Effect of a head geometry structure on the ignition performance of a combustor

The effects of sleeve length and LCHs on the ignition characteristics of a triple-dome sector combustor are studied by combining experimental and numerical methods. During the ground ignition experiment, the lean IFAR of a combustor with different head structure parameters is measured. According to the experimental results, the combustor head geometry with the lowest IFAR is selected for the high-altitude ignition experiment. The numerical simulation of relevant ignition conditions is also conducted, and the numerical results are used to assist in explaining the experimental phenomena. The results show the following: 1) the ignition performance of the combustor is significantly improved after plugging the LCH; 2) as sleeve length is shortened, the IFAR of the combustor decreases gradually, and the ignition performance improves significantly; 3) after shortening the sleeve and plugging the LCH, the width of the CRZ becomes wider, so that the CRZs between the heads blend and incorporate with each other. The transferring rate of energy and reactive radicals between the heads increases because of the expansion of the CRZ, improving the ignition performance of the combustor.