Applied Mechanics and Materials Vols. 448-453

Abstract: Coordinated engine control is an essential technology to improve shift quality. The influence of wet clutches’ towing torque in TC+AMT on shift synchronization process is analyzed, and a coordinated engine speed control strategy is proposed. Wet clutches’ towing torque and AMT shift synchronization process simulation models as well as the engine speed controller are developed by using MATLAB/Simulink. Finally the simulation of TC+AMT shifting process with wet clutches under engine speed coordinated control is carried out. The simulation results show that wet clutches’ towing torque can be used to reduce shift synchronization time, synchronization energy and the wear and tear of synchronizer as well as improving shift quality.

Abstract: The similitude requirement of excited load was deduced to maintain the consistent vibration between scaled model and prototype structure, based on the modal theory of multi-DOFs systems. The similitude of load frequency was another demand to maintain the consistent vibration, with the similitude of structure size and load magnitude. The dynamic similitude problem of a liquid tank was studied by finite element method and test analysis respectively. The results show that the similitude of load frequency is the insurance for the consistency of prototype and scaled model structures vibration. In a case the magnitude error of displacement is 8% to 10%, and the displacement and acceleration have all changed distinctly without the similitude of load frequency. All the results indicate that the similitude of load frequency is the key factor to analyze the scaled model dynamics correctly.

Abstract: In this thesis, a study was conducted on the magnetic phase transformation behavior and magnetocaloric effect (MCE) under a low magnetic field ranging from 0-1.5 T for the casted and annealed Gd₅Si₂Ge₂ alloys. The result shows that high-heat treatment significantly influences the structural and magnetocaloric properties of Gd₅Si₂Ge₂ alloy. High-heat treatment at 1573 K is beneficial to increasing Gd₅Si₂Ge₂-type monoclinic structure which benefits the first-order transition. The MCE of annealed Gd₅Si₂Ge₂ alloy drastically increases and the highest value of S_M~18.12 J/kg·K at 282 K upon H=1.5 T which is obviously larger than that of as-casted Gd₅Si₂Ge₂ ( S_M~5.03 kg·K at 276 K upon H=1.5 T). The giant magnetocaloric effect is obtained for Gd₅Si₂Ge₂ alloy by high-heat treatment.

Abstract: A multiple variable model is developed for a multiple-effect low temperature desalination system. Multiple-effect water desalination has been used in industry for decades due to its high efficiency and high quality of fresh water production. Here, its dynamical process is modeled based on the mass and heat conservation laws and then expressed in terms of a state space equation, enabling people to carry out analysis and design controllers.

Abstract: In order to optimize the structure and technology parameters of rotary drying, mathematical models of effective residence time and mass of loading were established based on the motion of solid particles in rotary dryer. Uniform design was applied in experimental design with material of rapeseed. Four independent variables such as structural parameter (cylinder inclination angle) and operating parameters (the rotation speed of rotary dryer, solids feed speed and airflow speed) were investigated. Prediction models of effective residence time and mass of loading were established by using software DPS7.05 to optimize the experimental design. The experiment results showed that under experimental conditions, the effects of airflow speed, rotation speed, the interaction of rotation speed with airflow speed and the interaction of rotation speed with solids feed speed on effective residence time were significant. Rotation speed, airflow speed, the interaction of cylinder inclination angle with solids feed speed and the interaction of feed speed with airflow speed had significant influences on mass of loading. By optimizing with multiple objective programming, the optimal parameters were obtained as follow: cylinder inclination angle of 1.8°, rotation speed of rotary dryer of 4 r/min, solids feed speed of 2.5 kg/s and airflow speed of 2.4 m/s. The research has important significance to well improve structure and technology parameters of rotary drying technology in solids drying.

Abstract: Advancements were made to the fuel supply system on the basis of the original X195 Diesel Engine correlating its structure features, and we designed exhausting performance experiments on the injection diesel engine burning the mixture of ethanol and diesel. The results show that: the exhaust smoke and the NOx emission could be significantly reduced by ameliorating the engine.

Abstract: Thermal film air flow sensor has the characteristics of high precision and fast response. The intake-air velocity in the engine inlet manifold is over the measurement range of the sensor, it is necessary to design special sampling flow channel which can reduce the flow velocity and achieve a stable flow state. The micro flow channel flow field was simulated with CFD meathod, the results show that a well-designed sampling port can obtain stable flow field and effectively low the speed, which can improve the velocity uniformity for measurement in the sensor location. The sampling channel conduces to obtain higher measurement accuracy.

Abstract: In this paper, differences between current major international and regional standards of foam extinguishing agent and China standard are analyzed. The reason of performance requirements and application characteristics are also stated and summarized. The research of this paper will greatly push forward the standardization development of foam extinguishing agent in China

Abstract: Multi-sensor information fusion is that fuses information of multiple sensors gained through use of redundant, complementary, or timelier information in a system can provide more reliable and accurate information. Under the research of mobile robot environmental information, a control method of fuzzy neural network based on T-S (Takagi-Sugeno) type is given, it can fuses effectively collected information from multiple ultrasonic sensors and a CCD camera, and realize the real-time control for mobile robot. The results on mobile robot obstacles avoidance verified the effectiveness of the method.

Abstract: Aiming at the nonlinear and time variant characteristics of a ramp control system, a fuzzy control method is applied to freeway ramp metering in this paper. A cell transmission model (CTM) to describe the freeway flow process is firstly established. Based on the model and in conjunction with nonlinear feedback theory, fuzzy control based ramp controllers are then designed. The ramp metering rates are determined by fuzzy control according to density tracking errors and error increments. Triangle curves are used for the membership functions of the fuzzy variables. The rule base including 56 fuzzy rules is also established. Finally, the controllers are simulated in MATLAB software. The results show that this method can achieve a perfect density tracking performance and eliminate traffic congestion. This approach is quite effective to freeway ramp metering.