Engineering calculation method for underexpanded supersonic rocket exhaust

An engineering calculation method for underexpanded supersonic rocket exhaust was presented, and the flow variables in three sections (near-field, primary section of the exhaust and far-field) were evaluated by using the quasi one-dimensional isoentropic flow model, the modified momentum-averaged behavior model and the self-preserving model respectively. The method suggested can be used to calculate the boundary of a jet, the velocity and temperature distributions in primary section and in far-field of the exhaust flow field. In comparison with the momentum-averaged behavior model, this method is more reasonable in dealing with the effect of Mach-disc and oscillating decline in supersonic core in primary section.