LES study on the breakup mechanism of LOX core in LOX/G[formula omitted] supercritical combustion

Abstract

Large-eddy simulation (LES) employing a flamelet/progress-variable approach that considers the real gas effect is applied to liquid oxygen/ gaseous hydrogen (LOX/GH2) supercritical combustion, and the breakup mechanism of the LOX core is investigated in detail by comparing it to that in the inert case. The results show that in the reactive case, O2 is injected into the chamber in the liquid state; that is, LOX, successively shifts to the supercritical and gas states and then reacts with H2 in the gas state. The present LES in the reactive case generally succeeds in predicting the LOX core breakup location in the experiment. In the reactive case, the LOX core breakup location is observed to be further downstream than in the inert case. This is because in the inert case, the turbulent vortices that are produced around the injector exit act to break the LOX core, whereas in the reactive case, the turbulent vortices are suppressed by the volume dilatation and viscous forces around the LOX core. In the reactive case, the LOX core tends to be compressed and thinned by the thermal expansion caused by the combustion reaction around the LOX core, and at the same time, is stretched and broken by the shear forces caused by the thermal expansion.