Abstract: This paper presents a dynamic modeling, simulation, and analysis of a Battery Electric Vehicle (BEV) according to vehicle dynamic characteristics. Mathematical model variants for the components of BEVs can be modeled and investigated using the Matlab/Simulink software. In order to compare the dynamic performance of BEVs under inverter fault and normal conditions, the CarSim co-simulation platform is configured with real vehicle calibration data. Using this approach, it was possible to quickly check for dynamic performance issues of an electric vehicle without incurring the time delay and cost. The simulation results such as motor output, vehicle speed/acceleration, and propulsion forces are discussed and compared for each drive mode.
Abstract: In this paper a three dimensional model of a spark ignition engine is presented using KIVA-3V code to investigate the combustion process of engine and gain a better understanding of what happens during this stage. The Whole engine cycle is simulated and the validity of the model is examined by experimental result of in-cylinder bulk pressure. the effect of ignition timing, spark plug location on the engine performance and pollutants of this engine has been investigated .The numerical results show that Relocating the spark plug near to the exhaust valves in order of taking advantage of higher temperature does not have the desired results. Using lean excessive air results in decreasing advancing the ignition results in an increase in the maximum bulk pressure and power of engine. Due to increase in maximum temperature of the combustion chamber the amount of NOx rises, too.
Abstract: — A finite volume method with non-gray gas model is applied to investigate radiative heat flux on the inside wall of nozzle. The radiative properties of non-gray gas are predicted by using weighted sum of gray gases model (WSGGM). Again, 4 gray gases and narrow band based WSGGM is used to predict total heat flux and spectral intensity on the nozzle wall. Finally, the hybrid use of 4 gray gases and narrow band based model is applied to reduce computational time preserving accuracy.
Abstract: —Metamodels have been widely applied in aircraft multidisciplinary design optimization (MDO) to alleviate the computation burden and improve the optimization efficiency. At present, there are various metamodel methods available, such as response surface method, Kriging model, moving least squares method, radial basis function, neural networks and so on. However, it is difficult to confirm which metamodel method is more promising, which is also an interesting question puzzled most designers. In this article, by using a series of numerical test problems with different inherent features, a comprehensive study is employed to compare five typical metamodel methods commonly applied in aircraft MDO under multiple metrics. In term of the comparison results, the conclusions are drawn and recommendations for selecting suitable metamodels in aircraft MDO practice are also summarized.
Abstract: Abstract—This paper presents the investigation of typical parametric geometry representation methods for airfoils, namely, PARSEC method, orthogonal basis function method and CST method. The investigation assesses the fitting accuracy of these parametric methods for various airfoils including the symmetric airfoil, cambered airfoil and supercritical airfoil. The design variables of these parametric methods are solved by the methods of least squares fit. The fitting results show that the fitting accuracy of CST method is better than other parametric methods for airfoil. The aerodynamics analysis models of these typical parametric geometry representation methods for airfoil are constructed. The pressure distributions calculated for different parametric methods are compared with the corresponding experimental pressure distributions for the actual airfoil geometry. Keywords-orthogonal basis function; PARSEC; CST; fitting accuracy; pressure distributions
Abstract: — In this paper thirty nine factors responsible for the dynamic loosening, under soft foot condition, of a bolted joint have been enumerated and its Interpretive Structural Modeling (ISM) has been developed. In this systematic approach of ISM, first of all a concept model of the problem has been formulated, followed by the formulations of Structural Self-Interaction Matrix (SSIM) and Reachability Matrix. The level of significance of each factor has been derived by level partitioning. The initial digraph is prepared on the basis of the canonical matrix. ISM based model is finalized after checking for conceptual inconsistency and necessary modifications. The MICMAC analysis is also conducted with the help of driving and dependence diagram, which states that factor 31 (vibration loosening) and 36 (additional stresses in the bolt) are the major threat for joint integrity and needs more attention.
Abstract: A stress analysis software based on MATLAB graphical user interface (GUI) has been developed. The developed software can be used to estimate internal loads on a fuselage and to compute the stresses at any point along the length of the fuselage of a given aircraft. The generalized formulation allows user to perform stress analysis even on tapered fuselages. The software is expected to be a useful tool for effective teaching learning process of courses on aircraft structures and aircraft structural design.
Abstract: —Temperature and pressure fields distribution during steam flooding through horizontal wells is very important to researches. The present experimental study is conducted to investigate the effect of steam flooding through horizontal injector-horizontal producer when high permeability section exists in the horizontal section and the ratio of permeability is 1:8. And 13 differential pressure transducers with high accuracy are installed in the model to measure the pressure field variation in reservoir during the experiments. And 13 differential temperature thermocouples are put on the model to measure the temperature field variation. Water cut and cumulative oil recovery are obtained. And effects of heterogeneity on temperature and pressure fields are obtained from experiment.
Abstract: The deep cave is an important storage space in the fractured-vuggy reservoir in the Tahe oilfield, with large differences in spatial structure and the complex relationship between oil and water features, so far, mainly in elastic energy as the driving force for mining; this paper, base on the elasticity theory, analyses mining characteristics of the three fractured-vuggy model, and found that the bottom hole pressure has a certain relationship with the fracture and cave properties, the bottom hole pressure equation was established, and verified the bottom hole pressure variation of three fractured-vuggy mode by physical simulation, and analyzed the relationship between cumulative production and accumulation of pressure drop curves, the results showed that: showed a single index of changes in bottom hole pressure for the single cave mode and single-fractured-cave mode, and the cumulative production and cumulative pressure drop curve is linear, the bottom hole pressure showed double-index change for the cave-fractured-cave model, and the cumulative production and accumulation of pressure drop curves have a bend segment, this research provide a basis for the development in the deep vuggy reservoir .
Abstract: Based on model of point-electrode and theory of vector sum, analytical expressions of electric fields on the basis of mathematical model has been deduced to reduce the ship corrosion electric field. Optimal result of current of compensatory anticathode has been gotten by appling evolutionary programming arithmetic and contrasted with actual effect. The simulation and experiment show that the electric fields around ship are reduced obviously, and the validity of the calculation method based on evolutionary programming arithmetic are proved.