Effect of Multi-Swirl Injector on Acoustic Damping for Reduction of Combustion Instability

Swirl injector with adjustable backhole length was analyzed to suppress high-frequency combustion instability in Liquid Rocket Engines. In order to analyze the effect of swirl injector as an acoustic absorber, swirl injector was regarded as a quarter-wave resonator and its damping capacity is verified in atmospheric temperature. Experiments were carried out with copied tubes on air core because the interior air core volume of injector has a direct effect on damping. From the experimental data, it is proved that increasing the number of injectors mounted at each anti-node point can increase acoustic damping effect. Also, when tuned injectors at 1L, 1T, 1L1T modes simultaneously are installed at each anti-node point of model chamber, the damping effect of tuned injectors with multi modes agree well with it of tuned injectors with single mode.會Ā᐀ﾖ⨀⡧綴ᄀĀ저會Ā저䂗ﾖ⨀큡綴Ā᐀會Ā᐀颗ﾖ⨀桢綴Ā᐀會Ā᐀ﾖ⨀つ綴瀀ꀏ會Ā䢘ﾖ⨀쁧綴Ā᐀會Ā᐀ꂘﾖ⨀塨綴ഀĀ㰀會Ā㰀ﾖ⨀綴Ā㈀會Ā㈀備ﾖ⨀衩綴Ā᐀會Ā᐀ꢙﾖ⨀綴Ā᐀會Ā᐀šﾖ⨀롪綴ሀĀ저會Ā저墚ﾖ⨀恥綴Ā저會Ā저낚ﾖ⨀綴ༀĀ저會Ā저࢛ﾖ⨀遦綴ഀĀ저會Ā저悛ﾖ⨀c綴؀Ā؀會Ā؀뢛ﾖ⨀顣綴㼀Ā切會Ā切ႜﾖ⨀졤綴Ā搀會Ā搀梜ﾖ⨀퀙鮬Ā저會Ā저삜ﾖ⨀栚鮬Ā저會Ā저ᢝﾖ⨀綴ࠀĀࠀ會Āࠀ炝ﾖ⨀롭綴