CN106828849A - A kind of catheter propeller of the bionical conduit of application - Google Patents

Abstract

The invention provides a duct paddle applying a bionic duct, including a duct and a rotor, characterized in that: the duct surface is a periodic wave-like structure composed of concave-convex protrusions, and the projection of the protrusion nodes on the duct surface is a trigonometric function curve, And the trigonometric function curve satisfies: f(x)=0.1Lsin(x*20π), where L is the chord length of the duct section airfoil, and the value range of x is 0-1. The advantage of the invention is that the new bionic ducted propeller has a simple structure, can change the inflow of the ducted propeller, improve the tail vortex of the ducted propeller, and improve the propulsion efficiency of the ducted propeller, and is a bionic special propeller for realizing energy saving and emission reduction of ships.

Description

A ducted oar using a bionic duct

technical field

The invention relates to a ducted oar, in particular to a ducted oar using a bionic duct, which belongs to the field of ship propellers.

Background technique

With the development of the ship industry, people have higher and higher requirements for ship propellers. In the new era, green ships and the energy saving and emission reduction of ships are the theme of this era. In order to achieve this goal, energy-saving ship types, energy-saving propellers and energy-saving appendages have emerged as the times require.

The concave-convex structure is a bionic structure obtained by biology professor E. Fish when he observed the shape of the front fin of the humpback whale. The researchers applied the concave-convex nodules to the leading edge of the fin and found that the bionic fin has greater power and less drag than ordinary fins. Mechanistically speaking, the concave-convex structure on the leading edge of the wing can generate vortices on both sides of the protrusion, making the fluid closer to the surface of the object and reducing the flow separation of the fluid; the concave-convex nodules can change the thickness of the boundary layer and improve the vortex in the boundary layer. structure, thereby achieving the effect of drag reduction.

As a special propeller, ducted propellers have the following advantages compared with traditional propellers: ducted propellers have higher propulsion efficiency at low speeds, that is, under heavy loads, so they are currently widely used on large ships such as tugboats and bulk carriers ; In addition, the ducted propeller also has good anti-cavitation performance under heavy load; the duct of the ducted propeller can also be used as a rudder, which can improve the maneuverability of the ship.

The ducted propeller is composed of a duct and a rotor. The section of the duct is generally an airfoil or a simplified airfoil. The duct used in this invention changes the section of the airfoil into a broken line, but the propulsion efficiency of the two is almost the same. . In order to improve the propulsion efficiency of the ducted propeller, scholars at home and abroad have optimized the section airfoil of the duct, and finally obtained high-efficiency ducts such as duct 19A and duct 37, but these are improvements on the airfoil section of the duct at the two-dimensional level. The invention improves the leading edge and the trailing edge of the catheter from a three-dimensional perspective, and has certain forward-looking and innovative features.

Contents of the invention

The purpose of the present invention is to provide a ducted propeller using a bionic duct, a special propeller that can improve the propulsion efficiency of the ship, and its unique front and rear edge structures can change the inflow of the ducted propeller, improve the tail vortex of the ducted propeller, and The propulsion efficiency of the ducted propeller can be improved.

The object of the present invention is achieved in this way: it includes a conduit and a rotor, and it is characterized in that: the surface of the conduit is a periodic wavy structure composed of concave-convex protrusions, the projection of the projection nodes on the surface of the conduit is a trigonometric function curve, and the trigonometric function The curve satisfies: f(x)=0.1Lsin(x*20π), where L is the chord length of the duct section airfoil, and the value range of x is 0-1.

The present invention also includes such structural features:

1. The height of the protrusion is 0.1-0.15 times the section length of the catheter.

2. The number of protrusions is 10.

Compared with the prior art, the beneficial effect of the present invention is: the concave-convex structure of the leading edge of the duct of the present invention can make the inflow of the duct paddle closer to the surface of the duct, the fluid in the duct is not easy to be separated, and the inflow in the duct is improved. At the same time, the protrusion on the trailing edge of the duct can improve the outflow wake vortex of the duct, reduce the energy loss of the fluid in the duct, increase the velocity of the outflow in the duct, and then improve the propulsion efficiency of the duct oar.

The invention has a simple structure, can change the inflow of the ducted propeller, improve the tail vortex of the ducted propeller, and improve the propulsion efficiency of the ducted propeller, and is a bionic special propeller for realizing energy saving and emission reduction of ships.

Description of drawings

Fig. 1 is a sectional profile diagram of a catheter 19A;

Fig. 2 is a side view of the present invention;

Fig. 3 is an axonometric view of the present invention;

Fig. 4a is a structural diagram of the present invention, and Fig. 4b is a schematic diagram of a common ducted propeller.

In the figure: 1, the trailing edge is raised, 2, the leading edge is raised.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 is a cross-sectional airfoil of a common ducted oar duct, which is a high-efficiency duct most widely used at the present stage. Fig. 2 and Fig. 3 respectively show the bionic ducted oar of the present invention. The cross-sectional shape of the duct of the bionic ducted propeller of the present invention adopts an airfoil 19A, and the protrusions 2 and 1 having concave-convex shapes on the leading edge and the trailing edge of the duct. The projection of the protruding node on the surface of the conduit is a trigonometric function curve, and the expression of the curve function is f(x)=0.1Lsin(x*20π), where L is the chord length of the airfoil profile of the conduit section, and the value range of x is (0-1 ). Moreover, the protrusion and the front and rear edges of the catheter are smoothly transitioned.

The height of the protrusions is 0.1-0.15 times the section length of the duct, and the number of protrusions at the leading edge and the trailing edge of the bionic duct oar of the present invention is 10.

The comparison between the present invention and common ducted oars is shown in Fig. 2, Fig. 3, Fig. 4a and Fig. 4b, in Fig. 2, a is the concave-convex pipe contour line of the present invention, b is the common pipe contour line; compared with common ducted oars, the present invention The new duct can change the inflow of the ducted propeller, improve the internal flow of the ducted propeller, improve the tail vortex of the ducted propeller, and improve the propulsion efficiency of the ducted propeller. The mechanism that the duct of the present invention can improve the propulsion efficiency of the duct paddle is: the leading edge of the bionic duct of the present invention is a concave-convex structure that can induce vortices on the surface of the duct, inject power into the fluid in the duct, and make the inflow closer to the surface of the duct , so as to reduce the flow separation at the front edge of the duct and improve the inflow of the duct oar; the rear edge of the duct has a concave-convex structure, which can improve the vortex at the outlet of the duct, reduce the energy loss of the water flow in the duct, and improve the propulsion efficiency of the duct oar. This new type of bionic ducted propeller has a simple structure, can improve the propulsion efficiency of ships, and meets the current requirements for the development of green ships in my country. It is a special ship propeller with great development prospects and market demand.

Claims (3)

1. a kind of catheter propeller for applying bionical conduit, including conduit and rotor, it is characterised in that：The catheter surface is by concavo-convex The periodicity wavelike structure of shape projection composition, projection node is projected as trigonometric function curve, and triangle letter catheter surface Number curve meets：F (x)=0.1Lsin (x*20 π), wherein L are conduit section aerofoil profile chord length, and the span of x is 0-1.

2. a kind of catheter propeller for applying bionical conduit according to claim 1, it is characterised in that：The height of the projection is 0.1-0.15 times of conduit length profile.

3. a kind of catheter propeller for applying bionical conduit according to claim 1 and 2, it is characterised in that：The number of projection is 10.