2006 Volume 48 Issue 145 Pages 281-292
A thermochemical model was newly proposed in the present study. The proposed model was developed to maintain an accuracy for detonation simulations with the detailed chemical reaction model under thermally perfect gas condition and to reduce computational load. The proposed model consists of three gas components, which are premixed detonable gas, burnt gas and inert gas. For chemical reactions, it is considered that premixed detonable gas reacts to burnt gas under the one-step irreversible chemical reactions. The thermodynamic data for premixed detonable gas and inert gas follow the enthalpy changes of the mixture as thermally perfect gas, and it is assumed that the burnt gas is isentropically expanded. In the present study, single-cycle and multiple-cycle operations of one-dimensional and two-dimensional single-tube Pulse Detonation Engine (PDE) were investigated with the proposed model. For one-dimensional simulations of single-tube, single-cycle PDE, advantages of the proposed model compared with some other models were shown using pressure and temperature profiles at the closed and open ends of the tube. Furthermore, two-dimensional simulations of single-tube, multiple-cycle PDE were carried out to investigate the spatial distributions and histories of the thermodynamic properties with the proposed and the detailed models. The spatial distributions and histories of the thermodynamic properties of the proposed model were in good agreement with those of the detailed model. The proposed model dramatically reduced the CPU time required for simulation to about 9 % for one-dimensional analysis and 14 % for two-dimensional analysis, compared with those of the detailed chemical reaction model.