Stimulation On Combustion Pressure Oscillation Of Diesel Engine Based On Kiva Program And Software Sysnoise

The contribution of the combustion noise of diesel engine to the whole noise of diesel engine takes up a significant position. The researchers in the field of internal combustion engine have recognized that the pressure oscillation play an important role for the combustion engine. However, there is still no definite theory about the pressure oscillation because of complicacy of the acoustic wave, therefore, it is of great importance to study the thermo-acoustic problems during the combustion of an engine.In this article, a diesel engine is chosen as the research object. Based on the diesel engine combustion cavity, the Thermo-acoustic model is established and the acoustic simulation is carried out. This article study on the character of pressure oscillation based on acoustic theory, as the fuel is burning in the combustion cavity.The program using the Fortran language combine KIVA program and the software SYSNOISE. From the KIVA program the sound source is calculated, and then with the sound source the software SYSNOISE display the pressure oscillation.Considering the factors of chamber volume and temperature on acoustic model of combustion cavity and the different fuel injection advance angle, the acoustic modes of the combustion cavity is calculated. The result shows that the resonance frequency rise up with the increase of chamber temperature, with the decrease of combustion cavity and with the increase of fuel injection advance angle of the engine. However, the temperature is the most important factor.Through studying on the pressure oscillation of diesel engine, it is found that the pressure oscillation starts from the phase of premixed combustion and the pressure oscillation rise up with the fuel injection advance angle. The pressure oscillation happen with several high resonance frequency. The fuel injection advance angle has little effect on the pressure oscillation frequency.