トルクコンバータに生じる気体性キャビテーションのモデルの検討

抄録

Development of gaseous cavitation model is becoming important issue for the development of automotive torque converter with more flattened shape. In the present study, cavitation simulation was carried out by using a popular homogeneous model based on simplified Rayleigh Plesset equation, but the Laplace's pressure instead of vapor pressure was applied for the driving pressure in the source terms. Two extreme conditions for partial gas pressure were considered; in model 1, fast diffusion due to highly turbulent flow inside torque converter is assumed so that the partial gas pressure is constant at its saturated value. In model 2, adiabatic bubble is assumed with sufficiently slow diffusion. As a result, both of two models could qualitatively well predict the appearance of cavitation as well as the gradual decrease of the pump torque, but the results were very different qualitatively; the torque dropped at higher cavitation number for model 1 but at lower cavitation number for model 2 than in the past experiments.