An Experimental Investigation of Gaseous Fuel Direct Injection in a Constant Volume Chamber

The present study provides two methods to investigate the injection system for the direct injection of gaseousfuel in spark ignited direct injection engine. The first method studies the jet’s tip penetration and cone angle ofCompressed Natural Gas (CNG) which is directly injected into a constant volume chamber. Constant volumechamber is a cylinder with the height and diameter both in the length of 130 mm. Z‐type schlieren imagingtechnique is employed for photographing. The high speed camera MotionBLITZ Cube / EoSens with the ability ofcapturing up to 100,000 frames per second (fps) is used. The jet tip penetration and jet cone angle are calculatedwhen ambient pressure is 7 bar and injection pressure varies from 10 to 50 bar. The second experiment involvescalculating and analysis of the effects of injection pressure and pressure of vessels on mass flow rate,experimentally. In the second method, pressure of vessel and injection pressure are varying between 5 ‐ 10 barand 30‐60 bar respectively. Jet tip penetration and injection pressure are in direct relation, whereas jet coneangle decreases with increasing of injection pressure. Moreover, ambient pressure does not affect considerablyon mass flow rate, but mass flow rate increases with increasing of injection pressure.

کلیدواژه ها:

Engine ، Compressed Natural Gas ، Direct Injection ، Image Processing