Research

Collision Detection between Moving Planar Objects Bounded by NURBS Curves.

 

Numerical collision detection is a basic and important process in various simulation applications. It is a low-level procedure which must be performed before higher-level applications can proceed. Its performance plays a crucial role in the overall efficiency and accuracy of many applications, such as simulation of rigid body dynamics, robotics and motion planning, tolerance verification, automatic assembly and disassembly, computer graphics and animation, and physical based modeling. For instance, when simulating physical and rigid body dynamics, interactions between large numbers of objects are computed based on the objects' geometry and physical laws. This computation may need to be done every millisecond. Collision detection often consumes 95% or more of the computation time in this kind of application as reported by Hahn [1]. Hence, collision detection is widely considered a computational bottleneck in many applications. In general, collision detection is needed whenever simulating solid objects in motion

 

This research will be conducted as follows:

 

•      - The types of collisions between objects will be identified.
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•      - The motion of objects will be described using the transformation matrices.
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•      - For each type of collision the governing equations will be derived.
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•      - Different types of bounding areas: axis aligned rectangle (AAR), oriented rectangle (OR), and sphere will be compared in terms of computation and intersection efficiency, The 'best' will be used in this research,
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•       - The bounding areas hierarchy to be used will be studied in terms of structure and construction method. This will include the study of the subdivision criterion.
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•      - The algorithm will be implemented in C++, and its performance and robustness will be evaluated.
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Flow and Heat Transfer Characteristics Downstream of Porous Sudden Expansion: A Numerical Study.

 

 

 

Flow in porous media has many important applications, including industrial furnaces, heat exchangers, thrusters, etc. Porous media can intensify fluid mixing and can increase the surface area in contact with fluids, making them effective in heat transfer augmentation.

Flow and heat transfer characteristics through porous media has been receiving much attention. Literature review, however, suggests that investigations on porous media have been conducted mainly for straight tubes or channels. The axisymmetric sudden expansion flow is encountered in numerous applications, including orifices, burners, and industrial duct and pipe systems. From a fundamental point of view, it is one of the most popular flows involving separation and reattachment. Work, therefore, is needed to characterize behavior of the flow and heat transfer through porous media in axisymmetric sudden expansion.

 

 

Investigation of the Numerical Solution of the Dynamics of Multibody Systems.

 

 

Abstract

Many variants of fast and readily-implementable recursive algorithms for the forward and inverse dynamics of serial manipulators have been formulated that are based on Newton-Euler and Euler-Lagrange formulation. The Newton-Lagrange (N-L) projection method results in a set of equations, which is a minimal, which has clear format that reveals the nature of the structure of the problem. Less work is devoted to study the numerical solution of these equations, which has the potential to render efficient recursive, modular, and parallel processing algorithms.

 

Recursive and modular algorithms for numerically solving of Newton-Lagrange equations will be investigated for their numerical efficiency, accuracy and stability as related to the system configuration, and as related to existing algorithms that are based on Newton-Euler or Euler-Lagrange equations.

 

 

The Effect of Using Nanofluids in Natural Convection Heat Transfer inside Horizontal Annulus.

 

 

Abstract

 

The Effect of using nanoparticles on natural convection heat transfer in horizontal cylindrical annuli will be investigated numerically using finite volume technique together with SIMPLE algorithm for different annulus diameter ratio DJDi. Aluminum oxide (Al2O3) nanoparticles in water as base fluid will be used in the current investigation. Different volumetric concentrations of nanoparticles will be examined.

 

The Effect of Using Nanofluids in Forced Convection Heat Transfer inside Circular Tubes.

 

 

Abstract

 

Circular duct is widely used geometry in fluid flow and heat transfer applications. Accordingly, its fluid flow characteristics have been analyzed extensively for various flow conditions including laminar, turbulent, fully developed, and developing flows. On the other side, its heat transfer characteristics have been analyzed extensively for uniform wall heat flux and isothermal wall boundary conditions. Circular channel flow is encountered in many applications including heat exchangers, boilers and solar energy applications. Advanced heat transfer fluids are required in many industrial applications. Fluid with high thermal conductivity is needed in energy-efficient heat transfer equipment.

The current project investigates numerically the effect of alumina/water nanofluid concentrations on heat transfer characteristics for turbulent flow inside circular tubes. Isothermal wall boundary condition is maintained and three inlet velocities are used. Various concentrations are considered and Nusselt numbers and shear stress profiles are obtained along the pipe length.

 

Turbulent Flow and Heat Transfer Characteristics in V-Tubes: A Numerical Study

 

 

Abstract

 

Due to secondary motion caused by the centrifugal force, curved tubes have been known to enhance heat and mass transfer. As such, they are being used extensively in heat exchangers and process industry. Examp.les of curved tubes incslude the helically coiled, spirally coiled, S-tubes, U-tubes, and others. Coiled tubes have received much attention. However, and due to turbulence complexities, mainly laminar flows have been investigated, albeit in detail.

 

In addition to the secondary flows present in curved tubes, turbulence poses another challenge to the analysts and experimentalists alike. Hence, few attempts have been made in the past to investigate turbulent flows in curved tubes, and mainly at low Reynolds numbers. In addition to the conventional effects of Reynolds and Prandtl numbers on flow and heat transfer characteristics in curved tubes, the Dean number becomes important as a non-dimensional parameter to characterize flow and heat transfer. Despite their practical importance in high performance heat exchangers, U-tubes have received relatively less attention. Unlike curved tubes, U-tubes are predominantly straight. However, the curvature has a substantial adverse effect on heat transfer characteristics downstream of the curvature.

 

 

Innovative Modeling Approach for the Lathe Machine, Part 1: Intermediate Turning Stage

 

 

Abstract

 

The importance of this research lays in solving the whirling motion problem in the lathe machine during turning employing an innovative modeling approach. This will have an impact on the needed high quality of the process. This mathematical modeling approach enabled us to solve the problem by modal analysis by transforming the problem into non-homogeneous equations with homogenous boundary conditions. The proposed approach enables us to predict the whirling motion at different locations on the cutting edge-work-piece system. This modeling approach can be the first step to start investigating some possible approaches to reduce the whirling motion in the lathe machine in the intermediate turning stage.

 

 

Synthesis and Characterization of Highly Uniform Hydroxyapatite Nanorods for Medical Applications.

 

 

Abstract

 

The significance and priority of scientific research and development in the field of health care steadily increase. Biomaterials -synthetic materials designed for prolonged use in contact with biomedia (implants for example) -are a particularly important field of research. The improvement of biomaterials is a major factor in the progress of many branches of medicine, particularly surgery. The most rapidly developing component of the biomaterials field is the use of various types of bioceramics, which substantially expands the surgeon's ability to restore many impaired functions of an organism. Therefore, the synthesis of high crystalline HA nanorod is of urgency and significance. Hence, HAp nanorods are desirable when biocompatibility is considered.

 

 

An Experimental Study on Thermal Performance and Emission of Hydrogen/LPG Fueled Engine

 

 

Abstract

 

Recently, many engines, usually converted from commercial compression or spark ignition engines, have been fuelled with alternative fuels such as natural gas (CNG, LNG), LPG (Liquefied Petroleum Gas), DME (Dimethyl Ether), and hydrogen is actively developed to solve these problems. This research will be focused on the study of a new alternative fuel and its effect on the thermal performance and pollutant emission of a spark ignition engine.

 

The specific objective of the present investigation is to initiate studies of the effect of hydrogen addition on LPG engine's thermal performance and emission of a spark ignition LPG engine using variable composition hydrogen/LPG mixtures (HLPG). Gasoline fuel will be used as a basis for comparison. The effect of using different percentage of hydrogen/LPG mixtures on engine power, specific fuel consumption, CO and NOx emission will be studied.

 

Spare Parts Quality when Produced by Traditional Machines and Universal CNC Machines.

 

 

Abstract

 

In industry, spare parts are produced by different methods. The most important one is the production using traditional machines such as lathes, milling machines and others. Also spare parts can be produced by using Universal CNC machines. The input to these CNC machines will be the raw materials and the product drawing introduced to the machine in a language known to the machine. In CNC machines the operator will not interfere in the manufacturing process. His work will be limited to selecting the suitable tool and fixing it. Then he will choose the suitable production speed.

 

Although the industry can use both traditional machines and the Universal CNC machines to produce spare parts. The quality of the product should be tested and compared to its cost. It is worth mentioning that some complicated spare parts cannot be produced by traditional machines.

 

Providing the necessary information about the product quality when both methods are used compared to the cost of production.