小排量汽油机进气歧管CFD优化设计与试验

摘要

The flow perfonnanee of intake manifold has great influence on dynamic property anti fuel economy of engine. The flow condition of each intake manifold within given pressure difference in the entrance and existence has been calculated by using CAD/CFD. Analyzing the disturbance of turbulence kinetic energy in flow field, optimization of core structure is conducted. The steady-state flow performance of intake manifold is improved. Prototype of intake manifold has been made based on optimized CAD model. It is verified by rig-test that efficiency of air charging and torque performance of engine with new intake manifold has been improved remarkably by eornparing with former intake manifold in medium speed and high speed. The advantage of CFD analysis and optimization is proved.%进气歧管的进气流通性能对整机动力性和经济性有重要影响。通过CAD／CFD方法，计算了原进气歧管模型在进出口定压差下各支管的流动状况，通过分析流场中湍动能的分布，对型芯结构进行了优化，使得进气歧管稳态流通性能得到提升。基于优化后的CAD模型制作了快速成型样件，经过发动机台架性能试验验证，与原歧管相比，发动机充气效率与扭矩性能在中高速段有了明显提升，很好地印证了CFD分析与优化的正确性。