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The structural concepts of Switch solenoid valve and proportional solenoid valve were proposed for the hydraulic shift control system of some hydrodynamic mechanical automatic transmissions. Shift oil pressure of stationary combination valve and proportional solenoid valve was modeled, simulated, contrasted and analyzed by dynamic simulation software in order to study the shift quality of heavy-duty vehicle automatic transmission. The results show that proportional solenoid valve is better to control the characteristic of shift oil pressure, reduce shift shock, improve shift quality and comfort than stationary combination valve. The correctness and validity of the model were verified through bench test, which reflected the dynamic characteristics of shift oil pressure of hydrodynamic mechanical automatic transmission. The results can be used to match the performance and predict heavy-duty vehicle shifting process, and to further lay the foundation for the enhancement of shift performance of the system.

Inspired by the successful applications of biological non-smoothness, the bionic non-smooth surface was integrated into the design of hydrodynamic torque converter (TC) to conduct the research on the drag reduction and efficiency improvement, the concaves model on non-smooth surface were established according to our analysis with the mechanisms underlying non-smooth unit mediated fluid drag reduction. The friction, shear and turbulent viscous in the concaves and adjacent areas on bionic non-smooth pump surface were found to decline after TC was subjected to transient numerical simulation tests using computational fluid dynamics (CFD) analysis method. The results showed that the head and efficiency of bionic pump was improved, compared with the original model, as well as the over performance of TC, the availability of the proposed design method could be thereby confirmed. As a kind of "green drag reduction" method, the bionic non-smooth surface was firstly applied to TC in this paper, the correlation reflected from non-smooth shell surface of pump can be provided for the design involving the drag reduction on surfaces of other internal components in TC.

This article presents a particle-tracking velocimetry experiment for studying internal flows of hydrodynamic torque converter whose guide vanes are adjustable. The torque converter in which the flow region is an enclosed space with multiple impellers has a complicated geometry of impellers. Complex flows in adjustable stator are experimentally analyzed using particle-tracking velocimetry, and some advanced measurement technique has been successfully applied. Under each opening, using the single-frame and triple-exposure method, images of the flow fields in the adjustable stator were recorded at three typical working conditions as the speed ratios were equal to 0 (stall), 0.5 (design), and 1 (idle). According to particle trajectories on the images, the displacements and corresponding velocity vectors were obtained. The internal flow pattern of the hydrodynamic torque converter with adjustable guide vanes were acquired and analyzed in two cases: the changing conditions under the same opening and the changing openings under the same condition.

For the design of double-row blades hydraulic retarder involves too many parameters, the solution process of the optimal parameter combination is characterized by the large calculation load, the long calculation time, and the high cost. In this paper, we proposed a multiobjective optimization method to obtain the optimal balanced solution between the braking torque and volume of double-row blades hydraulic retarder. Moreover, we established the surrogate model for objective function with radial basis function (RBF), thus avoiding the time-consuming three-dimensional modeling and fluid simulation. Then, nondominated sorting genetic algorithm-II (NSGA-II) was adopted to obtain the optimal combination solution of design variables. Moreover, the comparison results of computational fluid dynamics (CFD) values of the optimal combination parameters and original design parameters indicated that the multiobjective optimization method based on surrogate model was applicable for the design of double-row blades hydraulic retarder.

The flow characteristics research on fluid coupling has great important meanings to raise its performance. In order to study the three-dimensional flow characteristics of fluid coupling, the internal flow field of fluid coupling is analysised based on numerical simulation and experimental measurement. Numerical simulation computational results are compared with available experimental results. According to qualitative analysis of the internal flow field in fluid coupling based on experimental and theoretical research, visualization of internal flow field is achieved. It is found that flow phenomenon is nearly the same based on numerical simulation and experimental measurement.

The three-dimensional numerical simulation and analysis of the flow field in the dual-turbine torque converter was implemented with CFD, more details of the internal flow field in the torque converter and the torque distribution between the first turbine and the second turbine was analyzed. The non-steady-state solver has been used in the transient analysis of the internal flow in the dual-turbine torque converter, and the sliding-mesh theory is used in each interface of the inlet and outlet, making various components with the different rotary speed be united and calculated.

The internal flow that develops in hydrodynamic coupling is exceedingly complex, especially in incompletely liquid-filled hydrodynamic coupling which contain gas-liquid two phase. For such characterization, particle-image velocimetry (PIV) techniques are now regarded as a powerful tool .To investigate detailed knowledge and distribution characteristic of gas-liquid two phase flow field in hydrodynamic coupling, the PIV measurements are carried on braking condition and rated condition, liquid filled ratio are 50% and 75%. The results help us to understand the more information of flow field in hydrodynamic coupling.

In this paper, tailor-welded blanks (TWBs) of three dissimilar gages for the automotive body inner side panel were analyzed. The basic mechanical properties were measured through the tensile test. Based on this, a method of “rule of mixtures” for measuring the properties of weld metal in TWBs was introduced. Moreover, the error between the calculated results and the measured data for the weld-line specimen were analyzed.

The method of fault diagnosis of rolling bearings based on wavelet packet transform and support vector machine is presented. The key to fault bearings diagnosis is feature extracting and feature classifying. Wavelet packet transform, as a new technique of signal processing, possesses excellent characteristic of time-frequency localization and is suitable for analyzing the time-varying or transient signals. Support vector machine is capable of pattern recognition and nonlinear regression. According to the frequency domain feature of rolling bearing vibration signal, energy eigenvector of frequency domain is extracted using wavelet packet transform method. Fault pattern of rolling bearing is recognized using support vector machine multiple fault classifier. Theory and experiment show that such method is available to recognize the fault pattern accurately and provide a new approach to intelligent fault diagnosis.