The Investigation of Mixture Formation and Combustion with Port Injection System by Visualization of Flame and Wall Film 2011-01-1887
Mixture formation is one of the most important factors for the combustion in the spark ignition engine with port fuel injection. The relation between combustion and mixture quality, however, is not quantitatively well established.
In this study, the connection of combustion and mixture formation was explored with various measurement techniques. Borescopes were used in order to investigate the flame propagation in the combustion chamber and behavior of spray and fuel film on the wall in the intake port. For the purpose of investigation on the effect of mixture formation, various port fuel injection systems and parameters were tested and compared: direction, timing, and size of droplet. An SI engine for small vehicle was used under condition of 4 000 rpm.
The investigation by images obtained has shown that inhomogeneity of mixture causes low combustion stability, especially due to direct introduction of fuel droplets into the combustion chamber. Injection timing and direction cause different flame behavior due to difference of mixture and wall film formation. The rather bulky luminous emission visualized in the combustion chamber has been well related to existence of wall film in the intake port under wide open throttle condition.
Citation: Yumoto, M., Goto, K., Kato, S., and Iida, M., "The Investigation of Mixture Formation and Combustion with Port Injection System by Visualization of Flame and Wall Film," SAE Technical Paper 2011-01-1887, 2011, https://doi.org/10.4271/2011-01-1887. Download Citation