摘要

An experimental study on the combustion phenomena in a combustion chamber was performed by using a gaseous hydrogen/oxygen small rocket thruster with a single swirl-coaxial injector. The variables studied were the swirl intensity of the injector and the equivalence ratio between the propellants. Direct observation in the combustion chamber showed that a stable hydrogen/oxygen flame attached to the injector rim was formed independent of the swirl intensity. Applying swirl to the oxygen jet increased the flame diverging angle and decreased the flame length in the chamber, thus reducing the reaction time to reach completion of combustion. Measurements of the OH-radical intensity in the chamber revealed that the location of the actively reacting region moved with the swirl intensity and the equivalence ratio in the chamber. With oxygen swirl, high performance of Isp and C* was obtained, but without oxygen swirl the performance parameters decreased noticeably. This can be explained by the degree of completeness of combustion in the chamber attributed to the mixing between the propellants. The test results indicated that a small and simple thruster with a single swirl-coaxial injector offered good performance by increasing the mixing rate between the propellants.