Numerical Analysis of First and Second Cycles of Oxyhydrogen Pulse Detonation Engine

In the present study, numerical analysis of pulse-detonation-engine (PDE) cycles such as combustion, exhaustion, and fuel-injection phases is performed. A numerical scheme that is second-order accurate in time and space, MacCormack-total-variation-diminishing scheme, was used to solve the Navier-Stokes equations, where a simplified two-step chemical reaction model is introduced. The dependence of fuel-injection time on 1) the opening width of intake port, 2) reservoir pressure, and 3) injection angle is studied. Through the numerical analysis of PDE-cycle operation, the time required for each phase is estimated for each model PDE; the dependence on PDE tube length and the time required for PDE operation are studied. The performances (such as impulse and thrust density) of four straight model PDEs that have different tube lengths are estimated and compared with the theoretical result of Endo-Fujiwara analysis. The useful formula for impulse per unit area, which is similar to the expression in the theoretical analysis, is derived from the numerical analysis.