Papers by Keyword: Simulation Research

Abstract: Simulation study of the quarter car model was carried out in this paper. The influence of the stiffness of the suspension spring and the damping on the performance of vehicle suspension system was analyzed by the evaluation indexes: transfer function of body acceleration, transfer function of suspension dynamic stroke, transfer function of tire dynamic deflection. The simulation results shown that increasing the stiffness of the suspension spring would reduce the vehicle's ride comfort and increase the value of the first natural frequency of the sprung mass. And increasing the damping would reduce the peak response of the body acceleration which increasing the vehicle's ride comfort, but at the cost of increasing the high frequency vibration.

Abstract: The fluorescent lamp circuit experiment and the power factor improving experiment are both two traditional experimental projects in electrotechnics. It is very important for students to understand basic theory and develop experimental operation ability. Based on studying the basic structure of fluorescent lamp circuit and its working principle, a fluorescent lamp circuit schematics was built by using Multisim interactively. The simulation experiments were done based on the circuit. It could effectively save the time and cost of development. The parallel-capacitor circuit was designed to improve the power factor, and the experiments were done to compare power factor and phase between with and without the parallel capacitor. The study could help students learn and understand well this part, which has good promotional value.

Abstract: Aerobic biological wastewater treatment processes are difficult to be controlled because of their complex and nonlinear behavior, however, the control of the dissolved oxygen (DO) level in the reactors plays an important role in the operation of the facility, which affects the activity of activated sludge. A mathematical model of aeration system is established with the actual pulp and paper wastewater aerobic biological treatment process in Shandong as the background. Three control strategies for DO are designed. MATLAB simulation was carried out to compare the PID control, fuzzy control and fuzzy PID control of the step response. The robustness analysis of the three control systems is also researched. Conclusion is that the performance of Fuzzy PID control is the best.

Abstract: In order to study the effect of salinity wastewater discharging ways on the range of salt content rise nearby the outfall. Two three-dimensional numerical models of discharging ways which were single-port submerged-type and double-port submerged-type in the condition of subcritical flow were researched based on FLUENT. The range of salt content rise of the two discharging ways could be concluded according to the simulation results. The value of maximum salt concentration and average salt concentration of two discharging ways were compared and analyzed. The results showed that double-port submerged-type discharging way was better than single-port submerged-type discharging way.

Abstract: A grey box model of screw ground source heat pump unit has been established and operating characteristics of the unit using R22 refrigerants were simulated. The effects on refrigerating capacity, heating capacity, power consumption of the compressor and COP on conditions of cooling and heating have been analyzed with different inlet water temperature of evaporator and inlet water temperature of condenser. Results show that main factor which affecting COP of heat pump unit is inlet water temperature of condenser. The change of refrigerating capacity and heating capacity are mainly caused by inlet water temperature of evaporator. Measures can be done to decrease the inlet water temperature of condenser when the unit operates for a long time and to increase inlet water temperature of evaporator on very hot or very cold conditions.

Abstract: For a blow-off tunnel running, there is the large delay and lag issues. We build a mathematical model of the wind tunnel Mach number control by the test modeling method, then analyse the pros and cons of various control methods based on BP neural network control algorithm. Put forward genetic algorithm optimization neural network adaptive control method to solve the large inertia of the wind tunnel system, and large delay. A large number of simulation studies, run a variety of operating conditions for the wind tunnel simulation proved that the improved adaptive neural network PID control method is reasonable and effective.

Abstract: For a blow-off tunnel running, there is the large delay and lag issues. We build a mathematical model of the wind tunnel Mach number control by the test modeling method, then analyse the pros and cons of various control methods based on BP neural network control algorithm. Put forward genetic algorithm optimization neural network adaptive control method to solve the large inertia of the wind tunnel system, and large delay. A large number of simulation studies, run a variety of operating conditions for the wind tunnel simulation proved that the improved adaptive neural network PID control method is reasonable and effective.

Abstract: This work describes a simulation research concerning dynamic effect of multi-pad hydrostatic thrust bearing having rectangular recess, sector recess, ellipse recess and I-shaped recess in order to solve the loading capacity of the hydrostatic thrust bearing. Three-dimensional pressure field of gap fluid between the rotation worktable and the base has been computed by using the Finite Volume Method. This study theoretically analyzes the influence of recess shape on dynamic effect of the bearing according to computational fluid dynamics and lubricating theory, and the simulation results indicate that an improved characteristic will be affected by recess shape easily. Through this method, the safety of a multi-pad hydrostatic thrust bearing having different cavities can be forecasted, and the optimal loading capacity of such products can be achieved, so it can provide reasonable data for design, lubrication, experience and thermal deformation computation for hydrostatic thrust bearing.

Abstract: Along with the rapid development of China's economy, the CFD technology has become an indispensable new technology in industrial production, and it plays an important role in the development of industry. Using computational fluid dynamics software called FLUENT. The investigation was carried out in a mixer, which its internal flow of the 3-d numerical simulation. The unstructured tetrahedron grid and unsteady multiphase turbulent calculation model were used to analyze the mixer internal fluid concentration, speed and turbulent kinetic parameters e.g., which produce changes and distributions with the different stirring shaft speed, and reveal the law of internal flow. Through the simulation result, can conclude that the numerical simulation method can truly reflect the interior complicated flow state of mixing machine, and can provide theory basis for the design and improvement of the mixing equipment.

Abstract: The research and application of eco-driving has the important practical significance for the energy conservation and emission reduction of automobile industry. In this paper, a simulation model has been set up based on GT-Suite and mathematical models of driving operations to simulate three typical driving operations. The results show that the acceleration speed plays important role in the acceleration operation. As the acceleration speed increases, fuel economy significantly deteriorates. In the transmission operation, the engine should not be operated in the high speed region. Otherwise, the fuel economy would deteriorate. In the cruise operation, the gear should be selected to matching the speed. High-gear low speed operation will cause safety problems, while low-gear high-speed operation will cause significantly deterioration of fuel economy.