A parametric study on the role of near wall chemical reactions in O2/CH4 combustion chamber heat flux evaluation

Dealing with oxygen/methane thrust chambers, in case of extremely cooled walls, the near wall recombination plays a non-negligible role in predicting the wall heat transfer from the hot gas to the wall. Assuming as a reference test case the ISP1 oxygen/methane calorimetric thrust chamber in the case without film cooling, a parametric analysis is carried out varying chamber pressure, wall temperature and mixture ratio. In particular, for each test case the numerical solution obtained under the frozen flow assumption is compared to that of reacting flow taking into account the recombination of dissociated species. Comparing the numerical solution obtained by means of different kinetic mechanisms with increasing detail levels, the results show that the global Jones-Lindstedt kinetic mechanism including recombination reactions is able to capture the recombination heat increase and gives insight of boundary layer details.