EP2705903A1 - Rotor device, centrifuge vessel and centrifuge and method for producing same - Google Patents

Abstract

The rotor device (20) has an internal area for receiving a sample to be centrifuged. An outer wall provided with an outer surface (21) is arranged around rotation of the rotor assembly of the fluid. The surface portion of the outer surface is provided with a micro-channeled structure. The grooves are extended at a distance less than 2mm of adjacent grooves. Independent claims are included for the following: (1) a centrifuge bowl for receiving rotor; (2) a centrifuge; and (3) a method of manufacturing a rotor assembly.

Description

The invention relates to a rotor device, a rotor device receiving centrifuge vessel and a centrifuge having this rotor device and / or the centrifuge vessel, and the manufacturing method of these parts.

Centrifuges are used in particular as laboratory centrifuges to separate samples with components of different densities, e.g. to separate particles contained in fluids from the fluid or to separate liquids of different densities from each other. It uses the inertia of the particles, which have a greater density (mass per volume) compared to the surrounding fluid. The rotation of the sample about an axis of rotation of the centrifuge produces a centrifugal force whereby the denser constituents within the sample become radial, i. be driven outwards perpendicular to the axis of rotation. In biochemical and biomedical laboratories, in particular, macromolecules, living cells or cell fragments are separated from liquids, or liquids of different densities are separated from one another. The sample may be, for example, a solution of DNA in aqueous solution. To carry out a centrifugation, the sample container with the sample is placed in the area provided inside the centrifuge rotor for receiving the sample to be centrifuged. Then, as required, the sample is rotated at, for example, 14,000 rpm. For example, with such a number of revolutions, the DNA can be separated from the aqueous phase in the case of a sample consisting of an aqueous DNA solution. Centrifugation at up to 500,000 revolutions per minute is referred to as ultracentrifugation. This can be used e.g. Isolate lipoproteins from an aqueous solution.

Because of these high rotational speeds, centrifuge rotors must be made of a material that provides sufficient stability to the centrifugal forces encountered. Most of the rotors are made of aluminum, sometimes made of plastic, and have a high strength corresponding to the required strength on. Due to their large surface area and the high speed, the rotors experience high air friction, which is noticeable on the one hand in an undesirably high heating of the rotor and thus of the rotated samples and on the other in an increased power consumption of the centrifuge. It is therefore desirable to reduce the power dissipation caused by air friction, based on a predetermined number of revolutions of the centrifuges.

The object of the present invention is to provide a rotor device for a centrifuge, a centrifuge vessel and a centrifuge with at least one of these parts and a method for the production thereof, wherein, when using the centrifuge or at least one of the parts, a lower, related to a predetermined number of revolutions Power loss of the centrifuge results.

The invention solves this object in particular by the centrifuge rotor according to claim 1, the centrifuge vessel for holding the centrifuge rotor according to claim 13, and the method for producing at least one of these components according to claim 15. Preferred embodiments are in particular subject matters of the subclaims.

The invention is based on measurements and computer simulations in which it was surprisingly found that with large fixed-angle rotors a power loss of more than 500 watts is produced only by air friction. It turned out that almost the entire air resistance is generated by air friction on the rotor and on the boiler walls. It is this air friction that causes the rotor to heat up considerably at high speeds and then has to be counter-cooled by the boiler wall. The countercooling increases the air density in the boiler and thus the air friction.

According to the invention, the contact surface of the centrifuge exposed to the fluid flow, in particular the outer surface of the rotor device and / or the inner surface of the centrifuge Centrifuge vessel, at least partially provided with a microgroove structure. By locating the turbulent flow components within the grooves, the energy exchange between the turbulent flow regions and the free flow is reduced at some distance from the outer surface, so that the fluid friction or the power loss of the centrifuge can be reduced by up to about 10%. The optimization of the microgroove structure can be carried out, preferably as a function of the requirements of the intended use and the number of revolutions of the centrifuge, by setting various geometric parameters, which will be described below. The arrangement of groove structures on surfaces for friction reduction have been proposed after analyzes of the skin of sharks in other fields of technology ( Bechert, DW. et al .; Experiments on drag-reducing surfaces and their optimization with an adjustable geometry; J. Fluid Mech. 338 (1997) p. 59-87 ).

As a groove structure, in particular synonymous as a microgroove structure, a plurality of preferably substantially parallel grooves of the outer surface is referred to in the context of this invention, which extend in particular at a distance d of adjacent grooves less than 2 mm. This distance d may be constant, but it may in particular also change along the longitudinal course of adjacent grooves, in particular change continuously. Two substantially parallel grooves are adjacent when there is no third groove between them, or when the two grooves are separated by a single partition called a rib. The side walls of a rib thus form the side walls of adjacent grooves. The width B of a rib may in particular correspond to the distance d.

As laminar flow and as turbulent flow, two fundamentally different flow forms of a fluid are described in fluid mechanics. Most of the currents that occur in technical applications are turbulent. Turbulent flows generally have higher friction losses than laminar flows. The increased friction in the turbulent flow is created by momentum transport transverse to the main flow direction in the boundary layer. The flow directly at the overflowed surface is dominated by vortex structures, the high-energy fluid transport to the wall surface. This additional exchange of momentum compared to the laminar flow is the reason for the increased wall friction in the turbulent boundary layer. In the present case, the surface around which it flows is in particular a section of the outer surface of a rotor unit or the inner surface of a centrifuge vessel.

Preferably, the microgroove structure is adapted such that approximately or exactly the local Reynolds number Re ⁺ = 17. In this case $${\mathrm{re}}^{+}=\frac{u_{\tau }\cdot s}{\nu }$$

• ν - charakteristische kinematische Viskosität des Fluids (m² s^-1). Die kinematische Viskosität von Luft ist temperaturabhängig, und beträgt bei Raumtemperatur etwa ν = 15 m² s^-1;
• u_τ - charakteristische lokale Schubspannungsgeschwindigkeit des Fluids gegenüber dem Körper (m s^-1) wobei $$u_{\tau }=\sqrt{\frac{T_w}{\rho }},$$
  
  
  mit T_w der lokalen Wandschubspannung und ρ der Dichte des Fluids.
  s - Rillenbreite.

The individual formula symbols stand for the following sizes:

• ν - characteristic kinematic viscosity of the fluid (m ² s ^-1 ). The kinematic viscosity of air is temperature-dependent, and at room temperature is approximately ν = 15 m ² s ^-1 ;
• u _τ - characteristic local shear stress velocity of the fluid relative to the body (ms ^-1 ) where $$u_{\tau }=\sqrt{\frac{T_w}{\rho }}.$$
  
  
  with T _w the local wall shear stress and ρ the density of the fluid.
  s - groove width.

The relative reduction resistance RR is defined as RR = (FR ₁ - FR ₂₎ / FR _2, wherein FR ₁ is the friction resistance of a surface with the micro-groove structure and FR _2, the frictional resistance of a surface without the microgrooves structure. The value obtained for RR depends on the Reynolds number Re ⁺ . RR as a function of the Reynolds number has a minimum at about Re ⁺ = 17, ie the largest drag reduction is achieved at a local Reynolds number of 17.

A reduction in resistance is particularly important in those sections of a surface around which the greatest friction losses occur.

wobei die Wandschubspannung tangential zur Kontaktfläche wirkt. Dabei ist µ die dynamische Viskosität, u ist die Strömungsgeschwindigkeit mit Bezug auf die angeströmte Kontaktfläche, die mit zunehmendem Abstand von der Kontaktfläche in Richtung y senkrecht von der Kontaktfläche weg größer wird.In general, the wall shear stress, ie the frictional force which a flow of a normal viscosity fluid (Newtonian fluid) exerts on a surface, can be characterized by: $${\mathrm{T}}_{\mathrm{w}}=\mathrm{\mu }*\mathrm{.DELTA.U}/\mathrm{Dy}$$

wherein the wall shear stress acts tangentially to the contact surface. Here μ is the dynamic viscosity, u is the flow velocity with respect to the flowed contact surface, which increases with increasing distance from the contact surface in the direction y perpendicularly away from the contact surface.

wobei k= 0,41 und u⁺ = U₀ / u_t. Hierbei bedeuten U₀ die Geschwindigkeit der freien Anströmung und u_t die Schubspannungsgeschwindigkeit, die definiert ist als: $${\mathrm{u}}_{\mathrm{t}}=\sqrt{T_w/\rho }$$

wobei ρ die Dichte des Fluids ist, und ν = µ / ρ.Above a viscous sublayer y ⁺ = u _t * y / v, the universal turbulent velocity distribution applies: $${\mathrm{u}}^{+}=\mathrm{1}/\mathrm{k}*{\mathrm{lny}}^{+}+\mathrm{5}.$$

where k = 0.41 and u ⁺ = U ₀ / u _t . Here U _{0 is} the velocity of the free flow and u _{t is} the shear stress, which is defined as: $${\mathrm{u}}_{\mathrm{t}}=\sqrt{T_w/\rho }$$

where ρ is the density of the fluid, and ν = μ / ρ.

s und h, wie nachfolgend noch definiert.At the top of a vortex filling a groove with the diameter D _w = 2h = s applies with optimal resistance reduction $${\mathrm{y}}^{+}={\mathrm{u}}_{\mathrm{\tau }}*\mathrm{s}/\mathrm{\nu }=\mathrm{17}.$$

s and h, as defined below.

By experiment and simulation of typical laboratory centrifuges, their rotors and centrifuge boilers, a possible approximation formula for the calculation of u _{τ was} developed for the determination of u _τ as a function of the velocity u _{0 of} the free flow $${\mathrm{u}}_{\mathrm{\tau }}\approx {\mathrm{u}}_{\mathrm{0}}/\mathrm{11}.\mathrm{9}$$

The shear stress velocity u _τ is a measure of the friction force occurring. It can be determined, for example, by means of a finite element simulation and modeling of the complete flow around the surface in question. Thus, the sections of increased air friction can be determined on the basis of the shear stress velocity.

The rotor device preferably has a lower rotor section and preferably an upper rotor section which is arranged along the axis of rotation above the lower rotor section. When the rotor device is used as intended, the lower rotor section is arranged below the upper rotor section with respect to the direction of gravity. The lower and the upper rotor section may be separate parts, in particular may be connected or connectable, or may be formed in one piece. The lower rotor section and the upper rotor section are preferably connected by a central rotor section, wherein the maximum diameter of the central rotor section preferably corresponds to the maximum diameter of the rotor device D _max and preferably the maximum diameter of the central rotor section is preferably greater than the maximum diameter of the upper rotor section and is preferably greater than the maximum diameter of the lower rotor section, wherein in each case the diameter in a plane of rotation of the rotor device is meant.

Preferably, the rotor device has a radially inner region and a radially outer region. The radially inward region comprises the sections of the rotor device that lie within the imaginary cylinder, concentric with the axis of rotation, with the outer diameter D _A = c * D _max , where D _{max is} the maximum diameter of the rotor device in a plane of rotation is perpendicular to the axis of rotation, and wherein preferably c is a number with 0.1 <= c <= 0.9, preferably 0.4 <= c <= 0.9, preferably 0.5 <= c <= 0.9 , preferably about c = 0.5. The radially outward region includes the portions of the rotor assembly which are outside the radially inward region.

The maximum diameter of the rotor device D _max is preferably between D1 _max <= D _max <= D 2 _max , wherein preferably the lower limit D1 _{max is selected} from the group of preferred values {10 cm, 20 cm; 30 cm; 50 cm; 100 cm} and preferably wherein the upper limit D2 _{max is selected} from the group of preferred values {20 cm, 30 cm; 50 cm; 100 cm; 300 cm} is taken.

Preferably, the at least one section, which has the microgroove structure, is arranged in the upper rotor section. Centrifuges rotor devices have particularly high shear stress velocities, as has been shown in finite element simulations. It is possible and preferred that the at least one section, which has the microgroove structure, is arranged in the lower rotor section, alternatively or additionally. Preferably, the at least one section, which has the microgroove structure, is arranged in the radially outer region of the rotor device, since the larger shear stress velocities also occur here in the calculated rotor shapes; this is immediately understandable, because in the outer area, web speeds are higher at the same angular velocity. Alternatively or additionally, however, it is also possible and preferred for the at least one section, which has the microgroove structure, to be arranged in the radially inner region of the rotor device. By arranging the microgroove structure only in sections on the surface to be flowed around by the fluid, in particular an efficient balancing of production expenditure and reduction of friction is achieved. This also applies to the preferably provided according to the invention with microgrooves inner surface of the centrifuge vessel.

Preferably, the at least one section, which has the microgroove structure, is arranged in the region of the surface to be flowed around by the fluid, in particular outer surface of the rotor device or inner surface of the centrifuge vessel, in which based on this surface A, a proportion A _F with 40% <= A _F / A <= 60% of the greatest shear stress rates occur. Preferably 5% <= A _F / A <= 95%, preferably 40% <= A _F / A <= 60% and more preferably 40% <= A _F / A <= 60%. As a result, the expense of providing the microgroove structure is reduced, while the reduction in air friction caused by the microgroove structure is sufficiently achieved.

Preferably, substantially the entire outer surface of the rotor device is provided with the microgroove structure. As a result, the fluid friction can be greatly reduced.

Preferably, the grooves are formed as depressions in the surface. This can be achieved by machining the outer surface of the rotor means or the inner surface of the centrifuge bowl, e.g. by ablation techniques, e.g. by means of machining, by means of laser ablation, by wet or dry etching, in particular with the aid of photolithographic methods. It is also possible and preferable that the grooves are formed by rib members on the outer wall between which the grooves are formed. Such ribs may e.g. as an additional material to the surface to be patterned in a coating process, e.g. by vapor deposition of material onto the surface, in particular with the aid of photolithographic processes, in particular by means of sputtering or CVD (chemical vapor deposition). Furthermore, it is preferred that the microgroove structure is produced by printing a material, in particular a lacquer, on the outer surface of the rotor device or inner surface of the centrifuge vessel. The two geometric structures created by a removal process and a deposition process can be indistinguishable. The microgroove structure of the surface may also be made by attaching a microgroove patterned film to the surface and / or inside surface.

wobei s1 = (1-f) * s und s2 = (1+f) * s, f ausgewählt aus der Gruppe von Zahlen {0,01; 0,02; 0,2; 0,5; 0,6; 0,7; 0,8; 0,9; 0,98; 0,99}, und
vorzugsweise $$\mathrm{s}={\mathrm{Re}}^{+}*\mathrm{\nu }/{\mathrm{u}}_{\mathrm{\tau }},$$

insbesondere $$\mathrm{s}={\mathrm{Re}}^{+}*\mathrm{\nu }/\left({\mathrm{u}}_0/11,9\right),$$

wobei Re⁺ die lokale Reynoldszahl für die rotierende Rille ist, ν die kinematische Viskosität des Fluids und u₀ eine durchschnittliche Anströmgeschwindigkeit des Fluids gegenüber der Rille, wobei insbesondere die Reynoldszahl Re⁺ = 17 ist und wobei insbesondere bei Raumtemperatur 21°C die Viskosität von Luft ν = 15 * 10^-6 m² / s ist.Preferably, the microgroove structure is formed so that adjacent groove walls are arranged at a distance S _R from each other, wherein the distance S _R in the maximum Height h - or alternatively half the height h, for example, if a measurement at maximum height is not meaningful - adjacent groove walls and parallel to the surface portion with this groove or the outer surface or inner surface is measured, the height h starting from the point of lowest height of Groove in the direction perpendicular to the longitudinal direction of the groove and perpendicular from the outer surface of the rotor device away, or the inner surface of the centrifuge vessel away, is measured, preferably $$\mathrm{s}\mathrm{1}<={\mathrm{s}}_{\mathrm{R}}<=\mathrm{s}\mathrm{2}.$$

where s1 = (1-f) * s and s2 = (1 + f) * s, f selected from the group of numbers {0.01; 0.02; 0.2; 0.5; 0.6; 0.7; 0.8; 0.9; 0.98; 0.99}, and
preferably $$\mathrm{s}={\mathrm{re}}^{+}*\mathrm{\nu }/{\mathrm{u}}_{\mathrm{\tau }}.$$

in particular $$\mathrm{s}={\mathrm{re}}^{+}*\mathrm{\nu }/\left({\mathrm{u}}_0/11.9\right).$$

where Re ^{+ is} the local Reynolds number for the rotating groove, ν is the kinematic viscosity of the fluid and u _{0 is} an average flow velocity of the fluid relative to the groove, in particular the Reynolds number Re ⁺ = 17 and in particular at room temperature 21 ° C the viscosity of Air ν = 15 * 10 ^ -6 m ² / s.

Accordingly, the groove width s is preferably selected as a function of the shear stress rate to be expected in the section having the microgroove structure. The shear stress depends in particular on the rotational speed of a point of the outer surface v = r * ω, ω the angular velocity of the rotation and r the distance of the point from the axis of rotation. The velocity u _{0 of} the free flow can be assumed to be u ₀ = v or u ₀ = 0.5 * v. In particular, the groove width s becomes accordingly preferably selected as a function of a predetermined shear stress velocity and / or predetermined rotational speed.

The predetermined shear stress velocity may be that which is expected on average with respect to the typical revolution numbers, or which is to be expected in relation to the average of the higher revolution numbers of the centrifuge, where as higher revolution numbers those in the range of 0.5 times or 0 , 75 times the maximum number of revolutions up to the maximum number of revolutions of the centrifuge and / or the rotor device, or which is to be expected in relation to the average of the maximum occurring shear stress speed at maximum rpm, or that with respect to the average of those for the operation of the rotor device and / or the centrifuge bowl and / or the centrifuge most frequently expected number of revolutions is used. The predetermined shear stress velocity can also be determined so that the maximum friction reduction is achieved in the practical operation of a centrifuge designed in this way. This can e.g. be determined experimentally or by numerical simulation. Preferably, at least one - or each - of the groove parameters {s; H; T; B; α; β} is selected as a function of the predetermined shear stress velocity.

The local wall shear stress and thus the shear stress velocity vary with respect to their direction and magnitude depending on the position on the outer surface of the rotor means or the inner surface of the centrifuge bowl. The directions of wall shear stress, shear stress velocity, and near-surface flow of the fluid are the same. Optimal drag reduction is achieved when the groove width s at each point along the lengthwise direction of the groove is determined according to the equation s = Re ⁺ * ν / u _τ . However, a sufficient degree of resistance reduction is already achieved if the groove width is approximated to the optimum case. The groove width s may for example be constant over the longitudinal course of a groove, but is preferably variable over the longitudinal course of a groove. In particular, the groove width is preferably increasing Shear stress speed chosen smaller. In particular, the groove width is preferably selected to be smaller with increasing shear stress velocity.

Preferably, the groove width s _{i is} at least in a first portion of the outer surface of the rotor device smaller than the groove width s _ii in a second portion of the outer surface of the rotor device, wherein the first portion with respect to the axis of rotation radially outward than the second portion. Since radially outward, as a rule, larger shear stress velocities occur, the resistance reduction can thus be further optimized.

Preferably, the microgroove structure is formed such that adjacent groove walls are spaced from each other by a distance s, the distance s being measured at the maximum height h of adjacent groove walls, or in the middle height, perpendicular to the longitudinal direction of the groove and parallel to the outer surface of the rotor means, the height h being measured from the point of least height of the groove in the direction perpendicular to the longitudinal direction of the groove and perpendicularly away from the outer surface of the rotor device, where s is selected from a range for s with a lower limit s1 and an upper limit s2, such that s1 <= s <= s2, where s1 is selected from the values {1.0 μm; 5.0 μm; 10.0 μm; 20.0 μm; 30.0 μm; 40.0 μm} and s2 is selected from the values {40.0 μm; 50.0 μm; 60.0 μm; 70.0 μm; 80.0 μm; 100.0 μm; 200.0 μm; 500.0 μm}.

More preferably in the radially inner region of the rotor means, a first distance between adjacent groove walls wherein preferably S _inside unequal s _outside, and more preferably S _inside> S S is provided _inside, and a second distance provided S _outward in the radially outer region of the rotor device, _{on the outside} , which results from the mentioned dependence of s (u _t ). In a particularly preferred case, which was modeled in a simulation of a typical laboratory centrifuge, 60 μm <= s _inside <= 85 μm and / or 40 μm <= s _outside <60 μm. This results in optimal effects of friction reduction. Preferably, the average distance S _{means of} the grooves on a rotor device at 40 microns <= s _medium <= 80 microns, preferably 50 microns <= s _medium <= 70 microns, and more preferably 55 microns <= s _average <= 65 microns, preferably s _medium ≈ 60 microns.

The depth T of a groove corresponds to its height h. The height h of a rib corresponds to a height of the adjacent groove. Preferably, the microgroove structure is formed such that the height h of a groove is selected from a range for h having a lower limit h1 and an upper limit h2 such that h1 <= h <= h2, where h1 = (1-f2) * s and h2 = (1 + f2) * s, f2 selected from the group of numbers {0,2; 0.5; 0.6; 0.7; 0.8; 0.9}, preferably h = 0.5 * s, s as defined above.

Preferably, the microgroove structure is formed such that height h of a groove is selected from a range for h having a lower limit h1 and an upper limit h2 such that h1 <= h <= h2, where h1 is selected from the values {2, 0 μm; 5.0 μm; 10.0 μm; 20.0 μm; 30.0 μm; 40.0 μm} and h2 is selected from the values {40.0 μm; 50.0 μm; 60.0 μm; 70.0 μm; 80.0 μm; 100.0 μm; 200.0 μm; 300.0 μm}.

Preferably, B = 0.02 * s, where s is the spacing of adjacent groove walls, as defined above. This results in optimal effects of friction reduction. In a particularly preferred case, which was modeled in a simulation of a typical laboratory centrifuge, 60 μm <= s _inside <= 85 μm and / or 40 μm <= s _outside <60 μm.

Preferably, h = 0.5 * s, where s is the spacing of adjacent groove walls, as defined above. This results in optimal effects of friction reduction. In a particularly preferred case, which was modeled in a simulation of a typical laboratory centrifuge, 30 μm <= h <= 42 μm and / or 20 μm <= h <30 μm. Preferably, the average depth T _middle , equal to the average height h _medium , of all grooves of the rotor device T _medium ≈ 30 microns.

Preferably, the microgroove structure is formed such that the rib separating two adjacent grooves and thus forming the dividing wall has a width B which preferably corresponds to the distance d, the width B being at the maximum height h - or alternatively at half the height h - the partition wall, perpendicular to the longitudinal direction of the groove or rib and parallel to the outer surface of the rotor device or inner surface of the Centrifugal vessel is measured, where B is selected from a range for B with a lower limit B1 and an upper limit B2, so that B1 <= B <= B2, where B1 is selected from the values {0.05 microns; 0.1 μm; 0.5 μm; 1.0 μm; 10.0 μm} and B2 is selected from the values {0.5 μm; 1.0 μm; 1.5 μm; 3.0 μm; 5.0 μm; 10.0 μm; 50.0 μm; 100.0 μm}, where preferably B = 0.02 * s, where s is the spacing of adjacent groove walls, as defined above. In a particularly preferred case, modeled on a simulation of a typical laboratory centrifuge, 0.5 μm <= B <= 4 μm and / or 1 μm <= B <2 μm. The width B is in particular equal to the distance d of adjacent grooves.

Preferably, the microgroove structure is formed such that the rib separating two adjacent grooves has at least one side surface which subtends an acute angle α with a normal of the surface portion of the outer surface, preferably α from a range for α with a lower limit α1 and an upper limit α2 is chosen so that α1 <= α <= α2, where α1 is selected from the values {0,0 °; 5.0 °; 10.0 °; 20,0 °} and α2 is selected from the values {0,0 °; 5.0 °; 10.0 °; 20.0 °; 45.0 °}, preferably α = 0 °. This results in optimal effects of friction reduction. At least one side face of the rib, or both side faces, preferably does not run parallel to a plane of rotation which is perpendicular to the axis of rotation A. However, it is also possible and preferred that one or both side surfaces extend parallel to a plane of rotation.

Preferably, the microgroove structure is formed so that the rib, which separates two adjacent grooves, has a substantially rectangular contour in a cross section considered perpendicular to the longitudinal direction of the rib. This results in the largest effect of friction reduction, the 90 ° between groove bottom and groove wall, corresponding to the angle α = 0 ° correspond to the most preferred case.

However, it is also possible and preferred for the contour of the rib and / or the ribs and / or the groove structure, in a cross section considered perpendicular to the longitudinal direction of the rib, to have at least one of the following features: an edge at the transition between groove bottom and groove sidewall; a rounding at the transition between groove bottom and groove side wall; an edge at the junction between the groove side wall and the rib outer wall; a rounding at the transition between groove side wall and rib outer wall; a straight or rounded groove bottom; a straight or rounded rib outer wall. The contour of the rib (s) and / or the groove (s) in this cross-section may be triangular, in particular with respect to a triangle with equal sides. The contour of the groove structure may be serrated, wavy, with periodic or non-periodic progression along the outer surface, perpendicular to the longitudinal direction of the groove. Possible profiles of the groove structure are exemplary in the FIGS. 7a to 7h shown.

Preferably, the longitudinal direction of the groove or grooves, and / or its orbit, to which the grooves of the microgroove structure of the surface portion are aligned parallel, is formed so that at each point of its longitudinal course it has an angle β to the plane of a plane of rotation which is perpendicular to Rotation axis runs. Preferably, β is not equal to zero. However, it is also possible and preferred that β = 0 at least in sections or in the entire region of the surface section which has the microgroove structure, or in particular the entire surface which has the microgroove structure.

Preferably, β is substantially constant over the entire section having the microgroove structure. Independently thereof, β is preferably selected from a range for β with a lower limit β1 and an upper limit β2, so that β1 <= β <= β2, where β1 is selected from the values {0.0 °; 5.0 °; 10.0 °; 20,0 °} and β2 is selected from the values {0,0 °; 5.0 °; 10.0 °; 20.0 °; 45.0 °; 60 °}. This results in optimal effects of friction reduction.

For laboratory centrifuges determined by a finite element simulation, the ranges of preferably 5 ° <= β <= 20 °, 7 ° <= β <= 15 °, and particularly preferably 7 ° <= β <= 12 ° , more preferably β ≈ 9 °. In addition to a calculation by simulation, in particular a finite element simulation, the angle β can also be determined experimentally, for example by the China-Clay method, which is a kaolin spray-on method is, or by smoke visualizations. The direction of the shear stress velocity corresponds in particular to the direction of the near-surface fluid flow.

Preferably, the microgroove structure is designed so that at least two adjacent grooves differ in at least one parameter for determining the groove geometry, this parameter being selected from the group of parameters {s; H; T; B; α; β} is selected. At least one of these parameters, or all of these parameters, may change along the length of a groove or rib, or may be constant.

The microgroove structure is preferably designed such that the predetermined longitudinal direction of the grooves is adapted to the direction of the fluid flow flowing past this surface section, in particular corresponds to the locally applied direction of wall shear stress or the shear stress velocity, and in particular deviates from the concentric circulation direction with which each point of the outer surface rotated in a plane perpendicular to the rotation axis rotation plane.

The inner region of the rotor device can have a holding device for holding laboratory sample containers, in particular closable sample tubes. The holding device can have a fixed angle during rotation relative to the axis of rotation A of the rotor device, but in this case the holding device can be designed to adjust this angle by the user. Such a rotor device is called a fixed angle rotor. However, the retaining device can also have an angle which is variable during rotation relative to the axis of rotation A of the rotor device, in that the retaining device is designed to allow the sample vessels to swing radially outward about a pivot axis perpendicular to the axis of rotation A, following the centrifugal force and / or gravitation. Such a rotor device is called a swing-bucket rotor.

Particularly preferably, the rotor device is a fixed angle rotor. But it is also possible and preferred that the rotor device is a swing-bucket rotor, the one Has at least one, preferably three, four or more cup elements holding device, wherein a cup element rotatably mounted about a pivot axis on the base part of the rotor device. The base part is preferably arranged centrally along the axis of rotation A of the rotor device, preferably rotationally symmetrical to the axis of rotation A. A cup element is designed to receive at least one sample to be centrifuged. The at least one cup element has an outer surface with at least one surface portion which has the microgroove structure. It is also possible and preferable for the swing-bucket rotor to have a casing device which partially or completely encloses the holding device for the samples, partially or completely enveloped in the circumferential direction about the rotation axis and / or partially or completely enveloped upwardly and / or downwardly. The surface portion with the microgroove structure may in this case be arranged on the outside of the sheath device.

The rotor device or the casing device preferably has an outer wall section which is shaped in the manner of a cylinder and in particular carries this surface section with a microgroove structure. A cylinder-like shape can be particularly easily provided with a microgroove structure whose grooves extend at a distance d of adjacent grooves, in particular smaller than 2 mm.

The rotor device can have a cover device with which the inner region of the rotor device can be covered and / or closed. The cover device can have a closure element with which the cover can be fastened to the rotor device. The cover device and / or the closure element can have an outer surface with at least one surface section which has a microgroove structure whose grooves extend at a distance d between adjacent grooves of less than 2 mm.

The surface portion, which has a microgroove structure, in particular the surface portion of the outer surface of the rotor device and / or the surface portion of the inner surface of the centrifuge vessel, preferably runs partially or completely around the axis of rotation. A groove thus has, in particular, the shape preferably an open or preferably a closed loop. The microgroove structure preferably has the shape of a shell, which is in each case preferably rotationally symmetrical with respect to the axis of rotation A or, alternatively, is preferably not rotationally symmetrical to the axis of rotation A.

The invention further relates to the centrifuge vessel for receiving a rotor device according to one of the preceding claims, comprising an inner wall, which is surrounded by the fluid during rotation of the rotor device, the inner surface at least partially having a microgroove structure whose grooves - in particular substantially parallel to each other - at a distance d adjacent grooves smaller than 2 mm. The inner surface of the centrifuge vessel, and / or the centrifuge vessel itself, is preferably made of a metal, in particular a steel, or of plastic, or of ceramic, or comprises such a material. The centrifuge vessel may be a component composed of one or more components such that the internal volume, which contains the fluid in which the rotor device rotates, is partially or completely enveloped. Preferably, at least a portion of a side wall of the centrifuge tank is adapted to surround the axis of rotation A concentric and hollow cylindrical. Preferably, the side wall of the centrifuge tank is designed to surround the axis of rotation A concentric and hollow cylindrical. This hollow cylindrical region preferably has an inner surface with a microgroove structure which preferably partially or completely circumscribes the axis of rotation. The centrifuge vessel may have a bottom wall which may have an opening through which the drive shaft of the rotor means may be guided into the interior volume of the centrifuge vessel. The centrifuge bowl may have a top wall.

The invention further relates to the centrifuge, comprising a rotor device according to the invention and / or the centrifuge vessel according to the invention. The centrifuge is preferably a laboratory centrifuge, in particular for the centrifugation of chemical, biochemical, biological and / or medical samples. The centrifuge is preferably a tabletop device with a total volume of less than 0.5 m ³ , wherein the total volume is considered to be the volume of the smallest cuboid that can completely accommodate the laboratory centrifuge.

The centrifuge preferably has a bearing device for rotatably supporting the rotor device according to the invention within the centrifuge vessel according to the invention. The bearing device may comprise a ball bearing, roller bearings, or plain bearings. It may also have a rotating shaft which coincides with the (imaginary) axis of rotation.

The centrifuge may further comprise an electrical control device, in particular program-controlled control device, is controlled by the operation of the centrifuge. The centrifuge may comprise a data storage device and / or a computing unit, e.g. CPU or a microprocessor for processing / storing digital data. Preferably, an adapted set of control data is stored in the data storage device or can be stored subsequently. This data set is preferably adjusted so that the temperature inside the centrifuge, and / or the speed of the centrifuge are set to predetermined values, which are then automatically selected by the user of the centrifuge or the control program of the centrifuge, and in particular depending on the Choice of the user, to be optimally selected. The data set contains control data in which, based on the present microgroove structure of the rotor means and / or the centrifuge bowl, there is minimal air friction between fluid inside the centrifuge and the surface of the rotor means and / or the centrifuge bowl. These values can be determined by calculation, in particular a finite element simulation, and / or by experiments, wherein the air friction e.g. can be measured by the occurring waste heat.

Preferably, the centrifuge has a housing device which partially or completely shields its components, in particular the centrifuge vessel, from the environment. Preferably, the housing device has a lid device, through which the interior of the centrifuge can be opened and securely closed. Preferably, the centrifuge has a means for cooling the centrifuge bowl and thus indirectly for cooling the rotor means. It can be a heat transfer medium, for example a cooling fluid, which flows around the parts to be cooled and removes the heat, in particular the occurring fluid friction heat, which occurs between fluid in the centrifuge and the outer surface of the rotor device and / or the inner surface of the centrifuge vessel.

The centrifuge may further comprise a user interface, e.g. a display, touch screen, other input or output elements, via which the user can set the most important operating parameters, in particular the number of revolutions (s), the centrifugation (s) and / or Zentrifugiersequenzen can set, which is characterized by a certain number of revolutions and / or centrifugation or via which the user can select a centrifuging program or set the parameters of a centrifuging program, wherein a centrifuging program may include the number of revolutions, the centrifuging time (s) and / or centrifuging sequences, as well as pause times, the absolute start and / or end time , the time constant or variable cooling and / or tempering adjustment of the interior of the rotor device for receiving the samples, and the like.

The centrifuge may have a sensor device for detecting the actual rotational speed and / or vibrations. It may have an electrical control device for controlling the number of revolutions in dependence on the measured value. Possibly measured rotational speeds and / or accelerations / vibrations exceeding a tolerance value may be indicated e.g. cause the instantaneous braking of the rotation to a tolerable number of revolutions or to zero.

Preferably, the centrifuge is a laboratory centrifuge that achieves maximum revolutions up to 25,000 rpm. Preferably, the centrifuge is a high-speed centrifuge that achieves maximum revolutions up to 50,000 rpm. Preferably, the centrifuge is an ultracentrifuge that achieves maximum speeds of up to 500,000 rpm, especially when the latter Rotor device rotates in a vacuum. Also in the latter case, the inventive design with microgroove structure can reduce the power loss of the centrifuge.

The invention further relates to the method for producing a rotor device according to the invention or the centrifuge vessel according to the invention, wherein the microgroove structure is produced by a surface treatment, in particular by a removal method or a deposition method, as explained above, or by a casting method.

Preferred features of the centrifuge vessel according to the invention and the centrifuge according to the invention can, where appropriate, be derived from the description of the preferred features of the rotor device according to the invention, in particular with regard to the design of the microgroove structure.

• Fig. 1 zeigt schematisch ein Ausführungsbeispiel einer erfindungsgemäßen Zentrifuge, die eine Rotoreinrichtung und einen Zentrifugenkessel gemäß erfindungsgemäßer bevorzugter Ausgestaltungen aufweist.
• Fig. 2 ist die perspektivische Ansicht eines Ausführungsbeispiels der erfindungsgemäßen Rotoreinrichtung, die in dieser Ansicht entlang einer Ebene abgeschnitten ist, welche die Rotationsachse A enthält.
• Fig. 3 zeigt einen senkrecht zur Längsrichtung der Rippe betrachteten Querschnitt durch die Mikrorillenstruktur eines Flächenabschnitts der Außenfläche einer erfindungsgemäßen Rotoreinrichtung gemäß einer bevorzugten Ausgestaltung.
• Fig. 4 zeigt einen senkrecht zur Längsrichtung der Rippe betrachteten Querschnitt durch die Mikrorillenstruktur eines Flächenabschnitts der Außenfläche einer erfindungsgemäßen Rotoreinrichtung gemäß einer weiteren bevorzugten Ausgestaltung, in einem senkrecht zur Längsrichtung der Rippe betrachteten Querschnitt.
• Fig. 5 zeigt perspektivisch eine Mikrorillenstruktur eines Flächenabschnitts der Außenfläche einer erfindungsgemäßen Rotoreinrichtung gemäß einer weiteren bevorzugten Ausgestaltung.
• Fig. 6 zeigt eine Diagramm, das die Lage des Winkels β beschreibt, den eine Rille einer Mikrorillenstruktur, gemäß erfindungsgemäßer Ausgestaltung, in einem Punkt ihres Längsverlaufs mit einer Rotationsebene Re+ einschließt, die zur Rotationsachse senkrecht steht.
• Fig. 7a, 7b, 7c, 7d, 7e, 7f, 7g und 7h zeigen jeweils einen Querschnitt durch die Mikrorillenstruktur gemäß einer jeweils bevorzugten Ausgestaltung der Erfindung, wobei der Querschnitt senkrecht zur Längsrichtung der Rippe betrachtet wird.
• Fig. 8 zeigt eine perspektivische Ansicht einer erfindungsgemäßen Rotoreinrichtung gemäß einem weiteren Ausführungsbeispiel, bei der die Schubspannungsgeschwindigkeiten durch eine Finite-Elemente-Simulation ermittelt wurden, wobei die Richtungen dieser lokalen Schubspannungsgeschwindigkeiten als Pfeile eingezeichnet sind.

Further preferred embodiments of the rotor device according to the invention, the centrifuge vessel according to the invention and the method according to the invention will become apparent from the following description of the embodiments in conjunction with the figures and their description. Like components of the embodiments will be denoted essentially by like reference numerals, unless otherwise described or otherwise indicated by context. Show it:

• Fig. 1 schematically shows an embodiment of a centrifuge according to the invention, which has a rotor device and a centrifuge vessel according to the invention preferred embodiments.
• Fig. 2 is a perspective view of an embodiment of the rotor device according to the invention, which is cut in this view along a plane containing the axis of rotation A.
• Fig. 3 shows a perpendicular to the longitudinal direction of the rib considered cross section through the microgroove structure of a surface portion of the outer surface of a rotor device according to the invention according to a preferred embodiment.
• Fig. 4 shows a cross-section considered perpendicular to the longitudinal direction of the rib through the microgroove structure of a surface portion of the outer surface of a rotor device according to the invention according to a further preferred embodiment, in a cross section considered perpendicular to the longitudinal direction of the rib.
• Fig. 5 shows in perspective a microgroove structure of a surface portion of the outer surface of a rotor device according to the invention according to a further preferred embodiment.
• Fig. 6 shows a diagram which describes the position of the angle β, which includes a groove of a micro groove structure, according to the invention embodiment, at a point of its longitudinal course with a plane of rotation Re +, which is perpendicular to the axis of rotation.
• Fig. 7a, 7b, 7c, 7d, 7e, 7f, 7g and 7h each show a cross section through the microgroove structure according to a respective preferred embodiment of the invention, wherein the cross section is considered perpendicular to the longitudinal direction of the rib.
• Fig. 8 shows a perspective view of a rotor device according to the invention according to another embodiment, in which the shear stress velocities were determined by a finite element simulation, wherein the directions of these local shear stress velocities are plotted as arrows.

Fig. 1 shows a laboratory centrifuge 1, in this case a tabletop device for placement on a worktop, which has a rotor device 10 and a centrifuge vessel 100. The rotor device has an outer surface 11, the centrifuge vessel has a Inner surface 101 on. The rotor device is connected via a shaft 15 to a drive device 16, which may have an electric motor. The centrifuge also has a cooling device 17, with which the centrifuge vessel 100 is cooled controlled during operation. The cooling of the centrifuge bowl cools the fluid, here air, in the inner volume of the centrifuge bowl, and via the fluid also the rotor means, which rotates in the inner volume of the centrifuge bowl and heats the fluid and itself via the air friction. The centrifuge also has an electrical control device 18. The control means controls the drive means for bringing the rotational speed of the rotor means at the predetermined acceleration to the number of revolutions desired by the user, and also for shutting down again after the predetermined centrifuging time has elapsed. The inputs are made by the user via a user interface 19 of the centrifuge.

Fig. 2 shows an embodiment of a rotor device 20 according to the invention, which is cut in this view along a plane containing the axis of rotation A. The rotor device 20 extends concentrically to the axis of rotation A and substantially rotationally symmetrical, whereby an imbalance is avoided. The rotor device 20 has a base body 22, for example made of aluminum, a cover portion 23 which covers and closes the inner region of the rotor device, and a closure element 24, with which the lid portion 23 arranged in the closure position is securely fastened to the drive shaft 25, also on the base body 22 is securely fastened.

The rotor device 20 is designed as a fixed angle rotor. The rotor device 20 has a holding device for holding tubular sample vessels, whose tube containers are inserted through the openings of the holding frame of the holding device, and whose vessel caps are supported on the holding frame, so that the sample vessels are securely held by the holding device under the effect of gravity and centrifugal force ,

The outer surface 21 of the rotor device 20 has a surface portion 27. This has a microgroove structure for reducing the air friction, as described for example in the following figures. The surface section with the microgroove structure is arranged in a radially outer region which lies outside the imaginary cylinder 28 concentric with the axis of rotation with the outer diameter D _A = 0.75 * D _max and within the diameter of the cylinder 29 concentric with the axis of rotation D _max , where D _{max is} the maximum diameter of the rotor device in a plane of rotation perpendicular to the axis of rotation. The other regions of the outer surface 21 of the rotor device preferably also have a microgroove structure.

Fig. 3 shows a perpendicular to the longitudinal direction of the rib considered cross section through the microgroove structure of a surface portion of the outer surface 31 of a rotor device according to the invention according to a preferred embodiment. The grooves of the microgroove structure are at equal distances d = s apart and parallel to each other. The grooves are formed as depressions of the outer surface 31.

bestimmen, und die Schubspannungsgeschwindigkeit u_τ , vorzugsweise auch deren Winkel β, wird durch eine Finite-Elemente-Simulation bestimmt. Das Ergebnis einer solchen Simulation ist in Bezug auf eine erfindungsgemäß gestaltete Rotoreinrichtung 200 gemäß einem Ausführungsbeispiel in Fig. 8 gezeigt. Diese Rotoreinrichtung weist einen maximalen Außendurchmesser D_max von 24,5 cm auf. Die vorbestimmte Umdrehungszahl war 15000 U/min. Auf diese Weise konnten für die vorbestimmte Umdrehungszahl der Rotoreinrichtung, z.B. diese maximale Umdrehungszahl, die - insbesondere maximalen- Schubspannungsgeschwindigkeiten in Abhängigkeit von der Position an der Außenfläche der Rotoreinrichtung ermittelt werden - also die lokalen Schubspannungsgeschwindigkeiten, insbesondere deren Beträge und Richtungen.The optimum values for the groove spacing s can be calculated using the equation $$\mathrm{s}={\mathrm{re}}^{+}*\mathrm{\nu }/{\mathrm{u}}_{\mathrm{\tau }}.\mathrm{and}{\mathrm{re}}^{+}=17$$

determine, and the shear stress velocity u _τ , preferably also the angle β, is determined by a finite element simulation. The result of such a simulation is with respect to an inventively designed rotor device 200 according to an embodiment in Fig. 8 shown. This rotor device has a maximum outer diameter D _max of 24.5 cm. The predetermined number of revolutions was 15000 rpm. In this way, for the predetermined number of revolutions of the rotor device, for example this maximum number of revolutions, which are determined in particular maximum thrust velocities in dependence on the position on the outer surface of the rotor device, ie the local shear stress velocities, in particular their magnitudes and directions.

In the simulation in Fig. 8 In particular, the angle β was indicated by the near-surface flow, and thus the shear stress, and thus the shear stress at each surface point of the surface of the rotor device. Over large parts of the surface, in areas of the surface concentric with the axis of rotation, in particular in the regions located radially between the axis of rotation and the outermost wall, which extend at an angle not equal to zero to the axis of rotation, this angle β is between 7.6 ° and 10 , 3 °, which is a good approximation of 9 °. In the surface regions further inwards and outwards, which in particular enclose angles of approximately zero with the axis of rotation, ie extend essentially parallel to the axis of rotation, the angle β can, for example, be between 7.6 ° and -14.1 ° or -here in the innermost region- also partially between 10.3 ° and 13 °.

The calculation in the simulation according to Fig. 8 takes place, for example, taking into account a sufficiently small distance d _a , for example d _a = 1 μm, measured perpendicular to the outer surface of the rotor device, for the following reason: The boundary layer theory states that in a body flow, the flow velocity directly on the body surface must be zero, otherwise there would be no friction. Therefore, if the distance to the surface were set equal to zero in the calculation program when determining the velocity vectors, all the velocities would result in zero. In order to visualize a velocity field, one has to leave a sufficiently small distance between the surface and the computing plane to obtain even finite values for the velocity vectors. If this distance is increased, essentially only the absolute speed amount changes in accordance with the boundary layer profile. The situation is different with the shear stress. It is a measure of friction and greatest directly on the surface, with its direction coinciding with that of the velocity vectors.

In the example of Fig. 3 results in the radially outer region of the rotor device 20, a value u _τ = 5.0 m / s and in the radially inner region of a value u _τ = 3.5 m / s. Therefore, the optimum value for the groove pitch s is in the radially outward region s = 51 microns and _outside the radially inner region _inside s = 73 microns. The optimum groove depth h = T is set to T = 0.5 * s, ie T _outward = 26 μm and T _inward = 36 μm. The optimum distance between the grooves d = B, and thus the width B of the ribs separating adjacent grooves, is B = 0.02 * s, and thus B = 1.0 -1.5 μm. The angle between a groove wall 32 and a normal to the outer surface 31 includes here an angle α = 0 °. This corresponds to a preferred embodiment for α.

Fig. 4 shows a cross section through the microgroove structure of a surface portion of the outer surface 41 of a rotor device according to the invention according to a further preferred embodiment. The groove walls include here with the normal to the outer surface 41 an angle α> 0 °, namely in particular an acute angle, ie α <90 °, and in the present case about α = 7 °. This also corresponds to a preferred embodiment for α, because such grooves can be finished more easily, for example by means of laser ablation, than those with vertical walls (α = 0 °).

Fig. 5 shows in perspective a microgroove structure of a surface portion of the outer surface of a rotor device according to the invention according to a further preferred embodiment. The microgroove structure 64 has grooves 65 which extend parallel to an orbit about the axis of rotation and parallel to each other at a distance d of adjacent grooves less than 1 mm. An orbit can generally completely or partially revolve around the axis of rotation. A tangent C to the orbit is also a tangent C to the groove in the longitudinal direction. Fig. 6 shows a diagram which describes the position of the angle β, which includes a groove of a micro groove structure, according to the invention embodiment, in a point of its longitudinal course, and thus with respect to this tangent C, with a plane of rotation Re +, which is perpendicular to the axis of rotation. The optimum value for β, at which the air friction of the outer surface of the rotor device 21 is optimal, was calculated by means of a finite element simulation to β = 9 °. The angle β preferably varies along the longitudinal direction of a groove. Preferably, at least one of the parameters s, B, T also varies along the longitudinal direction of a groove.

wobei Φ = 90° - α. Δ ist die relative Widerstandsreduktion in %, als Funktion des Flankenwinkels Φ bzw. α, der Trennwand. Entsprechend sind die Rillen in dem betreffenden Flächenabschnitt auf der Außenfläche der Rotoreinrichtung angeordnet.The effect of the angle α of a side wall of the rib with the normal to the outer surface on the air friction can be estimated by means of the approximate equation $$\mathrm{\Delta }=-0.00003*{\mathrm{\Phi }}^2-0.0583*\mathrm{\Phi }+10.$$

where Φ = 90 ° - α. Δ is the relative resistance reduction in%, as a function of the flank angle Φ or α, the partition. Accordingly, the grooves in the respective surface portion are arranged on the outer surface of the rotor device.

Fig. 7a, 7b, 7c, 7d, 7e, 7f, 7g and 7h each show a cross section through the microgroove structure according to a respective preferred embodiment of the invention, wherein the cross section is considered perpendicular to the longitudinal direction of the rib / groove. The contour of a rib or a groove in this cross section or the profile is preferably rectangular ( Fig. 7a and Fig. 3 ), has angled side surfaces ( Fig. 7b and Fig. 4 ), is triangular, or the profile partially jagged ( Fig. 7c ) or quite jagged or from isosceles triangles ( Fig. 7h ), has rounded edges between side surfaces of the groove and the groove bottom ( Fig. 7d ) and / or in particular additionally has rounded edges between outer wall of the rib and side walls of the rib ( Fig. 7e ), has a rounded groove bottom, in particular with a circular contour ( Fig. 7f ) and / or in particular in addition to a rounded outer wall of the rib, in particular with a circular contour ( Fig. 7g ), wherein the profile can be wavy. The characteristics of these profiles can also be combined.

Claims (16)

Rotor device (10, 20, 200) of a centrifuge (1), in particular a laboratory centrifuge, designed for rotation about an axis of rotation A in a fluid, having an inner region for receiving a sample to be centrifuged,
an outer wall having an outer surface (21; 31; 41), which is surrounded by the fluid during rotation of the rotor device,
wherein at least one surface portion of the outer surface has a microgroove structure (34; 44; 64) whose grooves (35; 45; 65) extend in particular at a distance d of adjacent grooves, in particular with d <2 mm. Rotor device according to claim 1, characterized in that the grooves are formed as depressions in the outer wall of the rotor device and / or by rib elements on the outer wall, between which the grooves are formed. A rotor device according to claim 1, characterized in that the grooves are arranged so that they each extend in a substantially longitudinal direction parallel to the direction of wall shear stress resulting from the friction of the fluid on the outer wall when the fluid at a predetermined number of revolutions of the rotating Rotor device along the outer surface flows along. Rotor device according to one of the preceding claims, characterized in that a groove each having two adjacent groove walls, which are arranged at a distance s from each other, wherein the distance in the maximum height h of adjacent groove walls, perpendicular to the longitudinal direction of the groove and parallel to the outer surface of the rotor device is measured, the Height h is measured starting from the point of least height of the groove in the direction perpendicular to the longitudinal direction of the groove and perpendicular away from the outer surface of the rotor device, where s is selected from a range for s with a lower limit s1 and an upper limit s2, so that s1 <= s <= s2, where s1 is selected from the values {1.0 μm; 5.0 μm; 10.0 μm; 20.0 μm; 30.0 μm; 40.0 μm} and s2 is selected from the values {40.0 μm; 50.0 μm; 60.0 μm; 70.0 μm; 80.0 μm; 100.0 μm; 200.0 μm; 500.0 μm}. Rotor device according to one of the preceding claims, characterized in that adjacent groove walls are arranged at a distance s _R from each other, wherein the distance in the maximum height h of adjacent groove walls, perpendicular to the longitudinal direction of the groove and parallel to the outer surface of the rotor device is measured, the height h is measured starting from the point of least height of the groove in the direction perpendicular to the longitudinal direction of the groove and perpendicularly away from the outer surface of the rotor device, wherein $$\mathrm{s}\mathrm{1}<={\mathrm{s}}_{\mathrm{R}}<=\mathrm{s}\mathrm{2}.$$

where s1 = (1-f) * s and s2 = (1 + f) * s, f selected from the group of numbers {0,2; 0.5; 0.6; 0.7; 0.8; 0.9}, and
s = Re ⁺ * ν / (u ⁺ ), where Re ^{+ is} the local Reynolds number for the rotating groove, ν is the kinematic viscosity of the fluid and u ⁺ the shear stress velocity at a predetermined revolution number at the location of the distance determination, in particular the Reynolds number Re + = 17 and in particular ν = 15 * 10 ^ -6 m ² / s. Rotor device according to one of the preceding claims, characterized in that the height h of a groove is selected from a range for h with a lower limit h1 and an upper limit h2, so that h1 <= h <= h2, where h1 is selected from the Values {2.0 μm; 5.0 μm; 10.0 μm; 20.0 μm; 30.0 microns; 40.0 μm} and h2 is selected from the values {40.0 μm; 50.0 μm; 60.0 μm; 70.0 μm; 80.0 μm; 100.0 μm; 200.0 μm; 300.0 μm}. Rotor device according to one of the preceding claims and claim 3 or 4, characterized in that the height h of a groove is selected from a range for h with a lower limit h1 and an upper limit h2, so that h1 <= h <= h2, where h1 = (1-f2) * s and h2 = (1 + f2) * s, f2 selected from the group of numbers {0,2; 0.5; 0.6; 0.7; 0.8; 0.9}, preferably T = 0.5 * s. Rotor device according to one of the preceding claims, characterized in that the rib separating two adjacent grooves has a width B corresponding to the distance d, the width B being at the maximum height h of the partition, perpendicular to the longitudinal axis of the rib and parallel is measured to the outer surface, wherein the height h is measured starting from the point of least height of the groove in the direction perpendicular to the longitudinal direction of the groove and perpendicularly away from the outer surface of the rotor device, wherein B from a range for B with a lower limit B1 and an upper Limit B2 is selected such that B1 <= B <= B2, where B1 is selected from the values {0.01; 0.02; 0.05 μm; 0.1 μm; 0.5 μm; 1.0 μm; 10.0 μm} and B2 is selected from the values {0.5 μm; 1.0 μm; 1.5 μm; 3.0 μm; 5.0 μm; 10.0 μm; 50.0 μm; 100.0 μm}. Rotor device according to one of the preceding claims, characterized in that the rib separating two adjacent grooves has at least one side surface which forms an acute angle α with a normal of the surface portion of the outer surface, preferably α from a range for α with a lower one Limit α1 and an upper limit α2 is selected such that α1 <= α <= α2, where α1 is selected from the values {0,0 °; 5.0 °; 10.0 °; 20,0 °} and α2 is selected from the values {0,0 °; 5.0 °; 10.0 °; 20.0 °; 45.0 °}, preferably α = 0 °. Rotor device according to one of the preceding claims, characterized in that the rib, which separates two adjacent grooves, in a cross-section considered perpendicular to the longitudinal direction of the rib has a substantially rectangular contour. Rotor device according to one of the preceding claims, characterized in that at least two adjacent grooves differ in at least one parameter for determining the groove geometry, said parameter being selected from the group of parameters {s; H; T; B; α; β} is selected. Rotor device according to one of the preceding claims, characterized in that the grooves are arranged so that their longitudinal direction deviates from the concentric circumferential direction with which each point of the outer surface rotates in a plane perpendicular to the axis of rotation plane of rotation. Rotor device according to one of the preceding claims, characterized in that it comprises a cylindrical outer wall portion which carries this surface portion with the microgroove structure. A centrifuge vessel (100) for receiving a rotor device (10; 20) according to any one of the preceding claims comprising
an inner wall with an inner surface (101), which is surrounded by the fluid during rotation of the rotor device (10, 20),
wherein at least a surface portion of the inner surface of a microgroove structure (34;
44; 64) whose grooves (35; 45; 65) extend at a distance d between adjacent grooves, in particular with d <2 mm. A centrifuge (1) comprising a rotor device (10; 20) according to any one of claims 1 to 13 and / or the centrifuge vessel (100) according to claim 14. A method of manufacturing a rotor device according to any one of claims 1 to 13 or the centrifuge vessel of claim 14, wherein the groove structure is produced by a surface treatment or by a casting process, in particular by printing the microgroove structure on the outer surface or by applying a film with this microgroove structure.

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