The Shock Wave Generation Around the Diesel Fuel Spray with High Pressure Injection

It is well known that increasing the fuel injection pressure is effective for improving the diesel engine combustion. While studying the characteristics of the high pressure fuel spray which is injected in a high pressure vessel, the authors found weak shock waves generating around the fuel spray. To investigate the shock waves effect on the fuel spray the authors measured the propagation speed and pressure amplitude as functions of the injection pressure and ambient pressure. The results indicate that shock waves are generated when the fuel injection speed exceeds the ambient sonic speed. Also it was found that the pressure amplitude of shock wave is approximately 10 % of the ambient pressure and the shock waves spread at a sonic speed.

The above results make us think that, isn't it possible to use shock waves for combustion improvement.