Abstract: In this paper, k-Omega turbulence model is applied in the numerical simulation of the transit bus, several typical working conditions of the transit bus with windows open at a speed of 10m/s are investigated, and a custom function Q is introduced to characterize the amount of ventilation of each window. The results show that, when the transit bus travels with windows open, the air always flows into the carriage through the middle and rear side windows of the transit bus, and circulates in the carriage and then flows out of the carriage through the front side window. When the bus travels with sunroofs open in leeward mode and side windows open, the amount of ventilation is the maximum. This working condition is the best one when taking both drag coefficient and the amount of ventilation.
Abstract: Pipe can be regard as a dynamic system which is composed of quality, damping and stiffness matrix. The natural frequencies of the system will change when a crack occurs on the pipe. This paper studies the influence of a crack with various depths and directions on the natural frequencies of the system. Results of this paper give an experimental foundation for crack prediction.
Abstract: Based on overlapping grid, two cars were simulated numerically through computer when lane-changed overtaking and the aerodynamic characteristics of two cars were achieved. By analysis the coefficients of side force and yawing moment and the flow field around two cars when two cars’ position changed the flow motivation and rules of interference each other were researched. The conclusions can provide the theoretical foundation for the research of transient overtaking
Abstract: 2024 aluminium alloys are widely used in airframe construction.However,this series of alloys are susceptible to corrosion to limit their usefulness,In this study,electroless Ni-La-P alloy plating on aluminum alloy and the effects of pH value,temperature and concentration of LaNiO3 on deposition rate were investigated.Surface morphology and corosion-resistant of the electroless Ni-La-P deposits were evaluated.The results showed the corrosion-resistant in 5％ NaC1 solutions obviously enhance compared with original aluminum alloy using electroless Ni-La-P deposition method．
Abstract: In this work, steady air injection upstream of the blade leading edge was used in a transonic axial flow compressor, NASA rotor 37. The injectors were placed at 27 % upstream of the axial chord length at blade tip, the injection mass flow rate is 3% of the chock mass flow rate, and 3 yaw angles were used, respectively -20°, -30°, and -40°. Negative yaw angles were measured relative to the compressor face in opposite direction of rotational speeds. To reveal the mechanism, steady numerical simulations were performed using FINE/TURBO software package. The results show that the stall mass flow can be decreased about 2.5 %, and an increase in the total pressure ratio up to 0.5%.
Abstract: The satisfaction of customer requirements (CRs) is the objective of product configuration. A methodology Based on the Kano's model was proposed to explore customers' stated needs and unstated desires and to resolve them into different categories which have different impacts on customer satisfactions (CSs). The customer satisfactions are classified into group satisfaction and individual satisfaction, and each of them has three types with Kano theory. Group requirements items were selected frequently by the same kind of customers. Individual requirements were specified by the customer himself. Based on a combination of group satisfactions and individual satisfactions, the integrated satisfaction was determined. A case study is provided to illustrate the effectiveness of the presented method.
Abstract: In order to investigate the mechanism of mud membrane formation during slurry shield tunneling, mesoscopic particle flow method was carried out to examine the way of mud membrane forming in sandy soil stratum at granular level with combinations of the traits of (particle) discrete element model. This study showed that the type of mud membrane formed transit from mud cake to permeable mud cake zone with the increase of the diameter rate of strata soil and bentonite clay until an inability to form mud membrane in the same strata of the soil. Numerical simulation results and related laboratory test are in good accordance, it bear out that researching the It has been demonstrated that it is comparatively reasonable and effective to carry out research on the mechanism of mud membrane formation at a meso-scale level.
Abstract: The networked collaborative design has been the development trend of modern product design, the application of which has been constrained by the data access conflicts. This paper introduced the networked collaborative design method of product based on the Vault, and network collaborative function of Inventor by using the project management. Under the assistance of the Vault, we had solved the key technology of access conflict of networked collaborative design, and realized the remote design between the members of efficient coordination. In this way, we had optimized the design ideas, shortened the product development cycles and improved productivity.
Abstract: we studied the ground-state-transition of a vertically coupled three-layer single electron QDs system under a magnetic field by the exact diagonalization of the Hamiltonian matrix.
Abstract: Automotive chassis is an engineering system whose successful design requires harmonization of a number of objectives and constraints that, in principle, can be modelled as a constrained multidisciplinary design optimazation in the space of design variables. However, accurate recognition and effective management of coupling relationships among multisystem design models is fundamental to implementation of Multisystem Design. In view of the demand of complex automotive chassis system design, A model of multidisciplinary design optimazation(MDO) is built. Subsequently, The genetic algorithm is used for parameter recognition and representation among multidisciplinary model solvers (design systems). The parameter mapping approach enables integration of coupled disciplinary model solvers, and effective accelerates coordination of multidisciplinary computation processes. The parameter mapping approach has been applied to automotive chassis design, and which significantly improves the efficiency and quality of design.