Papers by Author: Jian Wei Yang

Abstract: In order to study the effect of oxygen-enriched combustion on the performance of exhaust emission of diesel engine, the 4jb1 diesel engine is taken as the research object and kiva-3v program was used to simulate the oxygen-enriched combustion progress by changing the concentration of oxygen and the concentration of carbon dioxide in the intake. The result showed that with the increased of carbon dioxide concentration, the ignition delay period was shorten and the rate of heat release rate was reduced effectively, the average pressure and the average temperature in cylinder were reduced and the emission of nitrogen oxide can be controlled effectively under the condition of oxygen-enriched.

Abstract: Hydroforming is a new deforming technology , Many of numerical analyzes of bulge forming processes have concentrated exclusively on the behavior of the deforming tube . Finite element models have been developed to simulate stroke-controlled tube , with particular emphasis on the state of stress and deformation of the work piece in the paper . The effects of using internal pressure alone and combined internal pressure and axial compressive load were investigated and it was found that the development of the location of maximum strain was dependant on the type of loading used.

Abstract: In order to establish the three-dimensional model of the crankshaft piston group, the application of characteristic modeling method was proposed directly through the designer to extract features from the BULL operations, and finally form a part model of the design and definition. Analysis of the expression of the crankshaft features and characteristics of the link, use Pro-E to build a diesel engine crankshaft and the piston rod group of feature modeling. a new three-dimensional assembly drawings was built. It provide a new design ideas for reserachers.

Abstract: To carry out electronic control EGR strategy in diesel engine the calculation model using GT-POWER is built. The thesis uses simulation software GT-POWER to establish the calculation model of 4JB1 intake system of turbocharged diesel engine with EGR system and the results agree well. According to the simulation results, it can predict the main performance indicators of the diesel engine when it works at the maximum torque condition, which includes A/F, IMEP, Maximum Pressure, and Intake Pressure and so on. Then after controlling the volume of gas by modifying the EGR valve, it can find out the regulation how EGR effects the engine's emissions, torque, power and the inlet temperature of turbo. Referring to the simulation results, it includes from four aspects：EGR can significantly improve the quality of emission gas; NOx and PM have a trade-off relationship; applying higher EGR rate in heavy load can lead to the low torque and power less; the inlet temperature of turbo increases with the augment of EGR rate. In the experiment, the inlet oxygen concentration method is used to determine the EGR rate, and to realize it, the oxygen concentration detection module is also successful designed. Then a close-loop control strategy is proposed based on the EGR rate. It proves it is feasible to guide the ECU programmer development by the simulation results of engine control strategy. It is also can be referred by other engine control systems development.

Abstract: To input rational customer requirements into engineering design process more effectively and improve product design quality and market response efficiency, this paper focuses on the interaction between market analysis and engineering design decision for the modular product. While many researchers have successful evaluated and optimized the design schemes, few, if any, have provided a bridge the customer selection and firms product development decision. After a review of the literature we introduce the flow of user-engineering design interaction including both maximize the utility of customer and the profit of the firm. On the user and market analysis flow, customer requirements are defined according to the target market, then the customer selection possibility link to the product attributes by utility function. Accordingly, the alternatives are corresponding to the module different product, and then using decision support problem method to search the optimal design parameters. Two design domains can share the design information and realize the cooperative design process by computer computing platform.

Abstract: To carry out product virtual design for diesel engine combustion system, the top-down method is used. The diesel engine combustion system is designed and each part is modeled in Pro/E. Pro/E is a solid modeler and this offers considerable advantage for solid model creation. Normally, the geometry is first sketched in 2-D and then extruded in the third direction to generate a 3-D model. In Pro/E, it is important to first create the base geometry. The base geometry is that captures the design intent of the part to be modeled. This base geometry can be created using either the EXTRUDE or the REVOLVE options. Once this base geometry has been created, additional features like holes, rounds, chamfers, fillets, ribs, etc can be added in the finishing stages of the part creation. The center of the bowl does not coincide with the center of the cylinder due to the presence of valve pockets. The obvious advantage of this configuration is that is gives the true geometry of the piston and the connecting rod ports can be accommodated when the piston is at the top dead center.