Propulsive performance of hypersonic oblique detonation wave and shock-induced combustion ramjets

A comparative study is presented of the propulsive characteristics of hyper sonic detonation wave and shock-induced combustion ramjets, The same ramjet design methodology is used to assess the propulsive performance of both ty pes of ramjets, The lower-upper symmetric Gauss-Seidel scheme combined with a symmetric shock-capturing total variation diminishing scheme are used to solve the Euler equations describing the two-dimensional hydrogen/air comb ustible flowfield with nonequilibrium chemical reactions including 13 speci es (H-2, O-2, H, O, OH, H2O, HO2, H2O2, N, NO, HNO, N-2, and NO2), Results obtained for flight Mach numbers 12 less than or equal to M-infinity less t han or equal to 16 and for a Right dynamic pressure of 67,032 Pa (1400 psf) show that combustor entrance temperatures T-ce (or inlet compression ratio s) substantially lower than the near ignition values of hydrogen/air mixtur e, adopted for the generation of a near Chapman-Jouguet oblique detonation wave in the combustor, entail significant performance augmentation. For the considered range of Right Mach numbers and value of Right dynamic pressure , the thrust of a shock-induced combustion ramjet is maximum for 650 less t han or equal to T-ce less than or equal to 700 K, and at this point the com bustion is entirely shock induced. The thrust generation can be enhanced by more than 10% and the fuel specific impulses improved by more than one-thi rd over their magnitudes corresponding to maximum thrust detonation wave ra mjets.