Computational engineering

CFD simulations using ANSYS FLUENT 6.3.26 have been performed on a generic SUV design and the settings are validated using the experimental results investigated by Khalighi. Moreover, an add-on inspired by the concept presented by Englar at GTRI for drag reduction has been designed and added to the generic SUV design. CFD results of add-on model and the basic SUV model have been compared for a number of aerodynamic parameters. Also drag coefficient, drag force, mean surface pressure, mean velocities, and Cp values at different locations in the wake have been compared for both models. The main objective of the study is to present a new add-on device which may be used on SUVs for increasing the fuel efficiency of the vehicle. Mean pressure results show an increase in the total base pressure on the SUV after using the device. An overall reduction of 8% in the aerodynamic drag coefficient on the add-on SUV has been investigated analytically in this study.

Rocker arms are part of the valve-actuating mechanism. A rocker arm is designed to pivot on a pivot
pin or shaft that is secured to a bracket. The bracket is mounted on the cylinder head. One end of a
rocker arm is in contact with the top of the valve stem, and the other end is actuated by the camshaft.
In installations where the camshaft is located below the cylinder head, the rocker arms
are actuated by pushrods. The lifters have rollers which are forced by the valve springs to follow the
profiles of the cams. Failure of rocker arm is a measure concern as it is one of the important
components of push rod IC engines.Present work finds the various stresses under extreme load
condition. For this we are modeling the arm using design software and the stressed regions are
found out usingAnsys software. Here in this thesis we are observing that by changing different
materials how the stresses are varying in the rocker arm under extreme load condition. And after
comparing results we are proposing best suitable material for the rocker arm under extreme load
conditions

A strategy for adaptive control and energetic optimization of aerobic fermentors was implemented, with both air flow and agitation speed as manipulated variables. This strategy is separable in its components: control, optimization, estimation. We optimized parameter’s estimation (from the usual KLa correlation) using sinusoidal excitation of air flow and agitation speed. We have implemented parameter’s estimation trough recursive least squares algorithm with forgetting factor. We carried separate essays on control, optimization and estimation algorithms. We carried our essays using an original computational simulation environment, with noise and delay generating facilities for data sampling and filtering.

Our results show the convergence and robustness of the estimation algorithm used, improved with use of both forgetting factor and KLa dead-band facilities. Control algorithm used in our work compares favorably with PID using the integrated area criteria for deviation between oxygen molarity and critical molarity (set point). Optimization algorithm clearly reduces energetic consumption, respecting critical molarity. Integration of control, optimization and adaptive algorithms was implemented, but future work is needed for stability. Methods were defined and implemented for stability improvement. We have implemented data acquisition and computer manipulation of air flow and agitation speed for actual fermentors.

Cassava starch extraction machine that is easy to assemble, operate and maintain was developed
and tested. The major components of the machine are hopper, mixing unit, extraction chamber
which houses the screw conveyor (auger) and sieve, discharge outlets and the power unit. The
machine was powered by 2 Kw electric motor. The working principle of the machine is by feeding
cassava mash and water through the hopper, under gravity they both fall freely into the mixing unit,
the rotated stirrers mixed the mash and water properly before it is discharged to the extraction
chamber where the screw conveyor move and rotates it over a sieve thereby causing the moist
starch to viberate.The machine was tested with 5kg TMS 30572 cassava mash with different water
quantity (10 – 22)litres. It was observed that at 18litres of water and 120rpm stirrers speed. The
output capacity was 25.2kg/hr and the extraction efficiency was 80%. The total cost of production of
the machine was N86,400.00. The machine is recommended for small and medium producers of
cassava starch.

A supercharger is an air compressor that increases the pressure or density of air supplied to an internal combustion engine. This gives each intake cycle of the engine more oxygen, letting it burn more fuel and do more work, thus increasing power. Power for the supercharger can be provided
mechanically by means of a belt, gear, shaft, or chain connected to the engine's crankshaft. Superchargers are a type of forced induction system. They compress the air flowing into the engine. The advantage of compressing the air is that it lets the engine squeeze more air into a cylinder, and
more air means that more fuel can be added. Therefore, you get more power from each explosion in each cylinder. Here in this project we are designing the compressor wheel by using Pro-E and doing analysis by using FEA package.
An attempt has been made to investigate the effect of pressure and induced stresses on the blade. By identifying the true design feature, the extended service life and long term stability is assured. A structural analysis has been carried out to investigate the stresses, strains and displacements of the
blade. An attempt is also made to suggest the best material for an blade of a turbocharger by comparing the results obtained for different materials. Based on the results best material is
recommended for the blade of a turbocharger

IMACS Multiconference on "Computational Engineering in Systems Applications"(CESA), October 4-6, 2006, Beijing, China. ... SINGLE PARAMETER MODEL OF MINIMAL SURFACE CONSTRUCTION FOR DYNAMIC GARMENT PATTERN DESIGN ... R. Ng, W. Yu Institute of Textiles and ...

International Journal of Advanced Information Technology (IJAIT) is a bi monthly open access peer-reviewed journal, will act as a major forum for the presentation of innovative ideas, approaches, developments, and research projects in the area advanced information technology applications and services. It will also serve to facilitate the exchange of information between researchers and industry professionals to discuss the latest issues and advancement in the area of advanced IT. Core areas of advanced IT and multi-disciplinary and its applications will be covered during in this journal.

Multiple Criteria Decision Making (MCDM) models are used to solve a number of decision making problems universally. Most of these methods require the use of integers as input data. However, there are problems which have indeterminate values or data intervals which need to be analysed. In order to solve problems with interval data, many methods have been reported. Through this study an attempt has been made to compare and analyse the popular decision making tools for interval data problems. Namely, I-TOPSIS (Technique for Order Preference by Similarity to Ideal Solution), DI-TOPSIS, cross entropy, and interval VIKOR (VlseKriterijumska Optimiza-cija I Kompromisno Resenje) have been compared and a novel algorithm has been proposed. The new algorithm makes use of basic TOPSIS technique to overcome the limitations of known methods. To compare the effectiveness of the various methods, an example problem has been used where selection of best material family for the capacitor application ha...

An attempt has been made to rank and classify potential fluids for power production through organic rankine cycle (ORC) using technique for order preference by similarity to ideal solution (TOPSIS) method. In order to calculate subjective weights for the attributes under study, the modified digital logic (MDL) method has been used. It has been observed under two different case studies that R601 (pentane) shows promising results. These fluids are further classified using dendrogram, a hierarchical clustering technique. Finally Pearson's correlation coefficient is calculated for the attributes to find out the nature and degree of correlation between different attributes under study.

International Journal of Advanced Information Technology (IJAIT) is a bi monthly open access peer-reviewed journal, will act as a major forum for the presentation of innovative ideas, approaches, developments, and research projects in the area advanced information technology applications and services. It will also serve to facilitate the exchange of information between researchers and industry professionals to discuss the latest issues and advancement in the area of advanced IT. Core areas of advanced IT and multi-disciplinary and its applications will be covered during in this journal.

CFD simulations using ANSYS FLUENT 6.3.26 have been performed on a generic SUV design and the settings are validated using the experimental results investigated by Khalighi. Moreover, an add-on inspired by the concept presented by Englar at GTRI for drag reduction has been designed and added to the generic SUV design. CFD results of add-on model and the basic SUV model have been compared for a number of aerodynamic parameters. Also drag coefficient, drag force, mean surface pressure, mean velocities, and Cp values at different locations in the wake have been compared for both models. The main objective of the study is to present a new add-on device which may be used on SUVs for increasing the fuel efficiency of the vehicle. Mean pressure results show an increase in the total base pressure on the SUV after using the device. An overall reduction of 8% in the aerodynamic drag coefficient on the add-on SUV has been investigated analytically in this study.

The computational engineering community is facing new modeling challenges because the advent of nanotechnology is clearly demonstrating the limitations of classical continuum mechanics. The discrete nature of matter leads to nonlinear and scale-dependent phenomena at the nanoscale, which cannot be captured in simple homogenization schemes such as those used in classical continuum mechanics. Discrete molecular or atomistic modeling clearly indicates the reasons for the inadequacies of classical continuum mechanics. However, discrete modeling still requires intense computational investment that limits its use to problems of very small length scales (sub-microns) and very short time scales (nanoseconds). Thus, although discrete modeling is a valuable technique to gain fundamental scientific insights into nanoscale phenomena, it is not a feasible strategy over length scales and time scales that are important in nanoscale problems of engineering significance. For example, it is still computationally infeasible to construct a discrete atomistic model of a complete nano-electronic device for design optimization purposes. It is equally difficult to develop a discrete molecular description of the construction of a nano-bio sensor that is based on the self-assembly of hundreds of protein molecules onto a functionalized gold substrate. As a final example, consider the difficulty of developing a discrete molecular model of a composite nanodielectric consisting of hundreds of nanoparticles embedded in a continuous matrix material. Clearly, a formal framework is needed to bridge between discrete molecular modeling and classical continuum modeling, for nano-engineering problems

We introduce HPCx—the U.K.'s new National HPC Service—which aims to deliver a world-class service for capability computing to the U.K. scientific community. HPCx is targeting an environment that will both result in world-leading science and address the challenges involved in scaling existing codes to the capability levels required. Close working relationships with scientific consortia and user groups throughout the research process will be a central feature of the service. A significant number of key user applications have already been ported to the system. We present initial benchmark results from this process and discuss the optimization of the codes and the performance levels achieved on HPCx in comparison with other systems. We find a range of performance with some algorithms scaling far better than others. Copyright © 2005 John Wiley & Sons, Ltd.

The integral-differential equation was obtained to simulate unsteady evolutions of the slender axisymmetric ventilated supercavity with the use of one-dimensional inviscid flow of the incompressible gas in the channel between the cavity surface and the body of revolution. For small ventilation rates, the solution of this equation was expressed as asymptotic series. In the steady case the nonlinear differential equation and its solutions were obtained. It was shown that the ventilation can increase and diminish the supercavity dimensions. Examples of calculations for different hull shapes are presented. At some critical values of the gas injection rate the cavity dimensions can become unbounded. Stability of steady and pulsating gas cavities was investigated in the case of the low gas injection rate.

This paper presents the use of Exodus method for computing potential distribution within a conducting oblate spheroidal system. An explicit finite difference method for solving Laplace’s equation in oblate spheroidal coordinate systems for an axially symmetric geometry was developed. This was used to determine the transition probabilities for the Exodus method. A strategy was developed to overcome the singularity problems encountered in the oblate spheroid pole regions. The potential computation results obtained correlate with those obtained by exact solution and explicit finite difference methods.

Several explicit high resolution TVD methods and their detailed application to steady and unsteady one-dimensional free surface channel flow problems are presented. Some of these methods are widely presented in the literature. Their evaluation is based on computations ...

A new estimate of the probability density function (PDF) of the sum of a random number of independent and identically distributed (IID) random variablesXi (i=1, 2, …, N)is shown. The sum PDF is represented as a sum of normal PDFs weighted according to theNPDF. The analytical model is verified by numerical simulations. The comparison is made by the Chi-Square Goodness-of-Fit test.

A subset S of V of a nontrivial fuzzy graph G is said to be strong (weak) triple connected
dominating set, if S is a strong (weak) dominating set and the induced sub graph <S> is a triple
connected. The minimum cardinality taken over all strong (weak) triple connected dominating set is
called the strong (weak) triple connected domination number and it denoted by stc (wtc).we introduce
strong (weak) triple connected domination number of a fuzzy graphs and obtain some interesting
results for this new parameter in fuzzy graphs.