Laval喷管内高速混合气的流场研究

Flow Field of High- speed Mixture in Laval Spray Tube

该文采用有限元分析软件ANSYS对Laval喷管内的混合气流场分布进行了流体动力学的有限元数值模拟,得到了比较直观的混合气流动轨迹。经过计算仿真找到了空气补偿装置的较佳位置,经实验验证发动机油耗降低,尾气排放减少,功率、扭矩增加。获得了所研究流场内流体的流动特性,理论分析与实验结果比较一致,可对发动机尾气排放、电控化油器的技术改造等问题的研究提供参考。

Through the finite element simulation analysis for the mixed fuel in the Laval spray tube of the gasoline engine, the results reveal that the airflow velocity rapidly increases after it enters the Laval spray tube. There appear obvious vortices in the in - take pipe and the loop flow in two sides of nozzle. Tracking the particle locus, we find the mix proportion of fuel and air is small, and its mix uniformity is not good. Then we use an air - compensation equipment to improve the mixed standard of fuel and air. Experiments prove that the gasoline engine consumes less fuel, reduces the exhaust emission, but its power and torque increase. The experiment results coincide with theoretical analyses in a great degree. This may provide references for the research of the exhaust emission.