Numerical study on combustion and heat transfer of a GOX/GCH4 pintle injector

Abstract

Aimed at providing a good thermal protection for a pintle injector from being overheated, a three-dimensional combustion and heat transfer coupled simulation is conducted based on a 500 N GOX/GCH4 pintle engine model. Further for such a pintle injector with double rows of injection holes, the effects of the ‘skip distance’ (Ls) and the interval between two rows of injection holes (Li) on the injector’s characteristics of combustion and heat transfer are studied. The results indicate that given the diameter of pintle injector body (Dp), the maximum temperature on the outer surface of the pintle injector decreases from 1756 K to 1404 K when Ls/Dp increases from 0.64 to 1.5, meanwhile the combustion efficiency has a change less than 0.2% with an average value of 0.9510. But when it changes Li, the lowest maximum temperature on the pintle surface of 1326 K and the biggest combustion efficiency of 0.9525 occurs at a middle value of Li/Dp = 0.18 when Li/Dp increases from 0 to 0.38. This paper tries to explain the influences of Ls and Li from the view of the changes of flowfield structures, which show an intensive sensitivity with different pintle injector configurations. The conclusions this paper gets would be greatly helpful for the engineering design of a pintle injector with double rows of injection holes.