Experimental Study on Ignition and Combustion Characteristics in a Sector Combustor with Three Pintle Injectors

With the growing demand for faster, higher, and more advanced aircraft, breakthroughs in aerospace propulsion technology remain an ongoing pursuit. In recent research and applications, pintle injectors have demonstrated outstanding performance due to their adjustable flow rate and stable combustion characteristics, making them the injector of choice for many new rocket engines. However, few studies have explored their feasibility in broader application scenarios. This study designed a sector combustion chamber equipped with three adjustable pintle injectors, using liquid oxygen/kerosene as propellants and an oxygen/kerosene torch igniter as the ignition device. A series of hot-fire tests were conducted. The experiments focused on the ignition process and combustion performance under idle-start conditions. Results showed that even at a low flow of 10% nominal rate, the sector combustion chamber maintained a combustion efficiency of 86.7%. The spray combustion characteristics of the pintle injectors governed the heat-release distribution, leading to high-temperature zones primarily located between two adjacent injectors. Consequently, thermal protection design must account for this circumferential variation in temperature distribution. This research verifies the feasibility of pintle injectors in sector combustion chambers, providing a basis for application in full-scale annular combustion chambers and offering a new explorable direction for the development of aerospace propulsion technology.