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INTELLIGENT DESIGN FOR AUTOMOTIVE INTERIOR TRIM STRUCTURES BASED ON KNOWLEDGE RULE-BASED REASONING
Xuebing Wei,Hang Yuan,Hui Wang,Yizhe Chen 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.5
An intelligent design method is presented for automotive interior trim structures based on rule-based reasoning. Design experience knowledge and design process are expressed as production rules, in which geometry model operations are integrated. Rule-based reasoning and model-associated operating are unified in one process. By rule-based reasoning, the intelligent design of interior trim structures is achieved. The method is designed as a three-layer architecture, including the interactive layer, the reasoning and executing layer and the knowledge library layer. The design of interactive dialog is implemented by NX/Open Block UI tool. The knowledge library, including the rule knowledge library and parameter knowledge library, is designed to store design knowledge rules and experience parameters. Each rule is designed in a class form. The data member is the condition of the production rule, and the member function performs operations described by the result of the production rule. The reasoning and executing module is designed through rule-based reasoning, which matches the design rules from the knowledge library according to known facts, calls model operations and updates facts. Based on NX platform, the intelligent design system is implemented by using NX/Open and C++ codes. Finally, the intelligence and efficiency of this method is verified.
Gas-liquid two-phase flow in the axial clearance of liquid-ring pumps
Renhui Zhang,Lei Tian,Guangqiang Guo,Xuebing Chen 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.2
In this study, the leakage flow in the axial clearance of a 2BEA-203 liquid-ring pump has been modeled through numerical simulation using the renormalization group k-ε turbulence model and the multiphase volume of fluid method. Numerical results show that the axial leakage flow reduces the inlet vacuum and efficiency of the liquid-ring pump. The gasliquid two-phase flow within the axial clearance region is completely separated. Several droplets are scattered outside the suction region, some of which flow back into the low-pressure suction region along the wall of the suction port. Given the axial asymmetry of the flow passage, the phase distribution within the impeller region is non-uniform along the axial direction. The numerically simulated pressure distribution within the axial clearance region accords well with the vortex distribution caused by the leakage flow. The leakage flow interacts with the impeller flow, and forms a corner vortex near the pressure side and a leakage vortex near the blade suction side. As the relative coordinate of the cross planes to the blade (sc −1 ) decreases from tip to hub, the corner vortex near the blade pressure side gradually weakens while the leakage vortex near the suction side gradually strengthens. These vortices mostly form in the suction and compression zones of the clearance region and significantly affect the overall pump efficiency. Findings of this study reveal the flow structure in the axial clearance of the liquid-ring pump and the interaction between the leakage and main flow.