Three-dimensional modeling of the combustion process of a scramjet by considering multi-stage reaction mechanism

In this investigation, the combustion process in DLR scramjet is simulated and studied by considering multi-stage reaction mechanism. This study is conducted both three-dimensionally and two-dimensionally with the help of Fluent. The results indicate that the general performance of the scramjet is nearly the same for both the two-dimensional and three-dimensional cases, that is to say the difference between calculated thrust and combustion efficiency in these two cases is only 0.9% and 1.4%, respectively. To consider the effect of the chemical mechanism on the obtained results, a two-dimensional simulation of the scramjet is done with a detailed chemical mechanism, which includes 19 reactions. The results illustrate that the general performance of the scramjet is nearly the same. More accurately, the difference between thrust and combustion efficiency in the one-reaction and the multi-reaction cases is only 1.4% and 4.4%, respectively. In contrast, the subsonic region behind the strut in three-dimensional case and multi-stage reaction mechanism case are 48.9% and 17.7% longer than the base case, respectively.