Abstract: This paper presents contact pressure prediction results based on numerical solution using implicit and explicit finite element method (FEM) verified by Hertzian contact theoretical solution. The contact pressure distributions are investigated for a simple cylinder-on-flat contact configuration model subjected to constant normal load. The FEM analysis is performed on two different aeroengine materials; Ti-6Al-4V and Super CMV (Cr-Mo-V) alloys. The predicted characteristics of the contact pressure distributions and the contact half-width lengths are verified with the Hertzian contact theoretical solutions. The results show that both implicit and explicit FEM are comparable with the Hertzian theoretical results. The difference of the calculated maximum contact pressure is less than 1%. The explicit method gives better agreement in terms of maximum contact pressure while the implicit approach has a better agreement in predicting the contact half-width length compared with the Hertzian contact theoretical solutions.

Abstract: The manufacturing process of drilling is considered the most efficient method for opening holes in a variety of materials. The present research aims to study the effects of the drilling parameters such as cutting speed, feed rate and tool diameter used on the prediction of the total thrust force and the thrust force due to the cutting action of the tool’s main cutting edges. The experiments were carried out by varying the drilling parameters and the output responses were mathematically modeled based on the response surface methodology. The analysis of variance was used to verify the adequacy of the mathematical models. The most significant input variables were recognized and the 3D response surfaces were plotted.

Abstract: We study the problem of thermosolutal convection in an annular cavity bounded by two very long cylinders, coaxial and isothermal, filled with a binary fluid considered incompressible and viscous. The partial differential equations modeling the problem are discretized using the finite difference method with ADI scheme. We focus our numerical simulation on the study of effects the control parameters (thermal Rayleigh number (10)^3≤(Ra)_T≤(10)^4, Lewis number 0.1≤Le≤20 and buoyancy ratio 0≤N≤30) on the flow structure, heat and mass transfer within the annular cavity. It is found that the increase of (Ra)_T number enhances the flow intensity, and improves the heat and mass transfer. On the other hand, in the ranges of variation of the control parameters, the flow structure remain unicellular. The Lewis number Le affects strongly the variation of heat and mass transfer. Also, there is a remarkable effect on the same quantities when we vary the aspect ratio R in the interval 1.2≤R≤1.6.

Abstract: To minimize the cost of inspecting the surface of a small battle ship, autonomous underwater vehicles (AUVs) can be used. However, it is extremely difficult to achieve both time and path tracking of an AUV for inspection. A robustness property of the velocity field control (VFC) is required to control an AUV while operating in an environment. The objective of this paper is to apply VFC-assisted linear quadratic regulation (LQR) for path trajectory to track an AUV while on a surveying mission. The results of the simulation and implementation were performed for circular path tracking.

Abstract: Anticipating potentialair transportation markets in the business jet type, the present work is devoted for exploring the possibilities of introducing some of a number of visionary and pioneering ideas and upcoming enabling technologies in the Aerodynamic and Conceptual Design Study of Quad-Bubble Business Jet (QB-BJ). In view of and driven by the vision for a fuel efficient, environmentally friendly and technology driven aircraft to meet global need within the next 15 years, the characteristics of the conceptually designed aircraft will be assessed in comparison to an appropriately chosen business jet as a reference. Major ideas derived from D8 are appropriately applied in the work, which starts with fuel efficient motivation, and followed by wing Aerodynamics and other critical factors related to the Design Requirements and Objectives.

Abstract: The enhancements of heat transfer characteristics in a vertical and horizontal uniformly heated circular tube fitted with conical nozzles of constant diameter ratio (d/D=0.538) and swirl generator for air flow with Reynolds number range of 5000-23000 are experimentally investigated. Three twisted-tapes of different twist ratios, Y=2, 3, and 6, are introduced in each run. The results show that the heat transfer process enhances as the tube position changes from vertical to horizontal. It is found that each application of the conical nozzle and the twisted tape can help to increase considerably the heat transfer rate over that of the plain tube by about 270% and 195%, respectively for vertical position and by about 280% and 207%, respectively for horizontal position. Empirical equations for Nusselt number, friction factor and performance analysis criteria for both positions to assess the real benefits in using the turbulators and swirl generator of the tube are developed.

Abstract: This paper reports on the analysis of human studies for the purpose of finger grasp using Gaussian-Principal Component Analysis (PCA) and PCA-Best Matching Unit (BMU). The method purposes to find the best grasping feature data using GloveMAP which is based on the fingers adapted grasping force movement. Gaussian filter method functions to smoothen the force signal at the same time capable to eliminate / remove the overshoot signal and suitable to be used for filtering grasping force input signals while minimizing the rise and fall time of the grasping object. Meanwhile for the finger grasping group features, the method of Best Matching Unit (PCA-BMU) was proposed whereas the concept of Euclidean Distance could be justify by the best grouping features according to the best neuron or winning neuron. The conclusion will determine grasping features of subject to grasp the experimental object with the thumb, index and middle fingers of GloveMAP. Based on fingers adapted grasping force movement, this study gives the grasping features in order to justify the best grasping for each subject grasp behavior.

Abstract: Turbo blowers are used in a variety of industrial applications including power plants. Recently, the problem of thermal management in the packaging of turbo blowers has garnered attention. Thermal problems occur because turbo blower capacity is increasing at the same that its volume is decreasing. Thus, in this paper, an experimental study was conducted to investigate the heat release performance of a 200 HP turbo blower. The experimental results successfully verified how the heat release performance of the 200 HP turbo blower could be optimized through an appropriate combination of air flow passage, fan, and filter.

Abstract: In this research study, aluminium-aluminium oxide (Al-Al2O3) metal matrix composites (MMCs) of different percentage reinforcements of aluminium oxide were prepared. Three different types Al-Al2O3 composite specimens having 10%, 20% and 30% volume fractions of aluminium oxide were fabricated using conventional powder metallurgy (PM) route. These composite specimens were fabricated under different compaction loads 15 ton and 20 ton. The effects of volume fraction of aluminium oxide particulates and compaction load on the properties of Al-Al2O3 composites were investigated. The obtained results revealed that density and hardness of the composites are significantly influenced by volume fraction of aluminium oxide particulates. Results also showed that density, hardness and microstructure of Al-Al2O3 composites are markedly influenced depending on the compaction load. The increase in the volume fraction of Al2O3 enhances the density and hardness of the Al-Al2O3 composites. It was found that for 20 ton compaction load, the composites show increased density and hardness as well as improved microstructure than the composites prepared under 15 ton compaction load. Moreover, optical micrographs revealed that aluminium oxide particulates are almost uniformly distributed in the aluminium matrix. It was also observed that after sintering process, flat and undistorted specimens were prepared successfully.

Abstract: Many factors affect total knee replacement TKR surgery success such as: fixation technique, geometry and material type of the implant. The implant material influences on the stresses developed in the surrounding bones of the artificial knee prosthesis and then will influence the bone stress shielding. It also causes high stress concentration at the stem tip region which leads to patient's pain. Mechanical stress shielding in the bone causes aseptic loosening of the tibial component and may lead to revision surgery. The bone/implant interface micro-movement is the main risk of aseptic loosening which means the implant loses its stability. These problems are a conflict that face implant design field. So this study investigates the effect of using uncemented titanium tibial tray with a thin polylactic acid hydroxyapatite PLA-HA coating material around the stem as a fixation technique to relieve this conflict. The results indicate a trend toward using thicker PLA-HA coating. It achieves an improvement for the stress shielding on cancellous bone and the stress concentration of the stem tip compared to the initial model. These outcomes indicate to reduce revision surgery need. This means low aseptic loosening as a result of a minimal micro-motion of the implant. It increases the implant performance and effectiveness. Also coating the implant has the ability to bond with bone tissue and that improves the implant stability with a long life.

Abstract: This work represents a comparison study between using the convenient titanium alloy used to manufacturing tooth implant with a novel material (eggshell powder with polyester). Total tooth implant model was analyzed through using finite elements analyzer ANSYS software (workbench) V.14 and with applying load and boundary condition it is easy to get all important design specification. Three percentages of volume fractions (represents percentage of eggshell powder to polyester) for the novel material (eggshell powder with polyester) had been studied where it was 0.3, 0.4, and 0.5 with mechanical properties measured by experimental tests. All the materials are assumed to be homogenous isotropic and experimental tests had been done for the novel material (eggshell with polyester) with different values of volume fraction 0.3, 0.4, and 0.5 in order to specify its mechanical properties. Results show high degree of agreement in stresses level between the convenient and the new material (at 0.5 volume fraction) for effective stress, Maximum principle stress (at 0.4 volume fraction) and equivalent elastic strain (at 0.3 volume fraction).

Abstract: Thermoelectric Modules are a useful way to extract waste energy such as exhaust heat from car engines. It works on the Seebeck effect, where an electromotive force will be generated when the junction of two dissimilar metals experience a temperature difference. The efficiency of these modules are low, but advantages of being small, lightweight and maintenance-free make it an attractive addition to applications where energy per unit weight or size is a primary factor. Among the key problems is obtaining a consistent voltage to power devices which depend on a consistent voltage more than maximum power. In applications where a higher voltage than the input voltage is needed, a boost convertor is able to reach the desired voltage at the expense of reducing current. This experiment aims to assess the performance of thermoelectric modules when connected to a boost convertor, taking into account: input and output voltage, current and power, as well as convertor efficiency against various temperature differences. The experimental test rig is using two HZ-20 thermoelectric modules connected in series to a 0.9-5V to 5V boost convertor. The hot side of the thermoelectric modules were heated through a heating block while the cold side were water cooled at room temperature through cooling blocks. The surface temperature region near the hot air inlet and outlet is measured using a temperature sensors and thermal imager. Testing showed that at a temperature difference of 71℃, the input voltage and current of 1.76V and 0.76A were increased and decreased respectively to 4.17V and 0.17A. At a temperature difference of 135℃, the input voltage and current of 4.09V and 0.89A were increased and decreased respectively to 5.14V and 0.66A. It was also noted that the efficiency of the boost conversion increases with temperature difference, ranging from 53% at 71℃ to 93% at 135℃. In conclusion, the usage of a boost convertor is able to increase the input voltage, decrease the input current, and reduce the range of output voltage over a range of temperature differences. The conversion process is also more efficient when the input voltage is close to the desired output voltage.

Abstract: This paper presents the development of an Image Based Visual Servoing control law for a differential drive mobile robot navigation using single camera attached on the robot platform. Four points image features have been used to compute the actuation control signals: the angular velocities of the right wheel and the left wheel. The actuation control signals move the mobile robot at the desired position such that the error vector in the image space has been minimised. The stability of the proposed IBVS control law has been validated in the sense of the Lyapunov stability. Simulations and real-time experiments have been carried out to verify the performances of the proposed control algorithm. Visual servoing platform (ViSP) libraries have been used to develop the simulation program. Real-time experiments have been conducted using a differential drive mobile robot where a Beaglebone Black Board was used as the main hardware controller.

Abstract: In this study, a composite material contains a matrix (Polyester resin) and a natural fiber (Date Palm) was prepared .The volume fraction for date palm fibers was 40% in all prepared composite materials. All samples were prepared by hand layup process, A chemical treatment with at 5% concentration Maleic acid solutions for 20 hours is conducted, and tested under erosion conditions. The results showed a weight with time due to presence of voids on the surface of composite. Also, the increasing of drying time leads to decrease water absorption in case of longitudinal direction and transverse direction for date palm fibers in composite materials.

Abstract: Mimicking flapping wing biosystems, a flapping wing ornithopter is modeled and analyzed to produce lift and thrust for forward flight by considering the motion of a three-dimensional rigid and thin bi- ad quad-wing in flapping and pitching motion with phase lag, Basic Unsteady Aerodynamic Approach incorporating salient features of viscous effect and leading-edge suction is utilized. Parametric study is carried out to reveal the aerodynamic characteristics of flapping quad-wing ornithopter flight and for comparative analysis with various selected simple models in the literature..