Combustion instabilities in a high-pressure, multi-element combustor are studied in order to understand the relationship between the chamber and injector dynamics. A linear array of seven injectors supplies premixed natural gas and air into a rectangular combustion chamber designed to promote high-frequency, transverse thermoacoustic instabilities. The effect of equivalence ratio on the combustion dynamics was investigated for two injector lengths, 62.5 and 125 mm. For all operating conditions, the 125 mm injectors promote high-amplitude instabilities of the fundamental transverse (1T) mode, which has a frequency of 1750–1850 Hz. Reducing the injector length significantly lowers the instability amplitudes for all operating conditions and, for lower equivalence ratio cases, excites an additional mode near 1550 Hz. The delineating feature controlling the growth of the instabilities in each injector configuration is the coupling with axial pressure fluctuations in the injectors that occur in response to the transverse modes in the chamber.

为了了解燃烧室与喷射器动力学之间的关系，研究了高压，多元素燃烧室中的燃烧不稳定性。由七个喷射器组成的线性阵列将预混合的天然气和空气供应到矩形燃烧室中，该燃烧室设计成促进高频横向热声不稳定性。研究了两种长度分别为62.5和125 mm的喷油器的当量比对燃烧动力学的影响。在所有工作条件下，125 mm进样器都会促进基本横向（1T）模式的高振幅不稳定性，该模式的频率为1750–1850 Hz。减小喷油器的长度可显着降低所有工况下的不稳定性幅度，对于较低的当量比情况，可激发1550 Hz附近的附加模式。