A Study on Combustion and Mixture Formation Under Transient Operation of Small SI Engines

In a small-type spark ignition engine with a carburetor, the mixture strength charged into a cylinder, that is, the combustion state and the exhaust emissions are remarkable influenced by instantaneous behavior of the fuel liquid-film flow on the inner wall of intake pipe, during transient running.

Accordingly, the authors carried out some experiments in order to explicate the instantaneous mixture formation in cylinder, and go a step further, they had numerically analysed on the model of fuel supply system during the transient operation as the carburetor's throttle valve is stepwise changed.