Study on the Influence of Low-Frequency Flow Oscillation on the Atomization Characteristics of Gas-Centered Coaxial Centrifugal Nozzle

Abstract

The dynamic atomization characteristics of gas center coaxial centrifugal nozzle under the condition of pressure oscillation in the supply system were studied by applying external excitation through the flow pulsator. Obtaining spray image by high-speed photography while using hydro-mechanical pulsator to get generate of supply system. The results show that the spray width changes periodically with low-frequency pressure oscillation. For self-pulsation sprays, it is challenging to maintain a “Christmas tree” shape with low-frequency oscillation. Pressure oscillation can effectively suppress spray self-pulsation. However, the pressure oscillation amplitude may be much larger than that of the self-pulsation itself. Therefore, the premise of applying this method is that the applied external excitation cannot stimulate or amplify the combustion instability. The gas post-pressure drop determines the amplitude and frequency of the self-pulsation, while the excitation frequency will slightly affect the amplitude and frequency of the self-pulsation.