Recent Advances in Detonation Techniques for High-Enthalpy Facilities

Abstract

Detonations can be used to generate a high-pressure gas of high acoustic speed to drive a shock tube. Recently, detonation-driven facilities have been Implemented for meaningful hypervelocity testing. These facilities can be operated with the detonation wave propagat-ing downstream or upstream. The advantages and problems associated with these methods are discussed. In addition to a performance comparison between these two modes, com-parisons with other high-performance techniques, such as free-piston and gun tunnels, is also made. At present, detonation-driven facilities are generally of lower performance than free-piston tunnels. However, they appear easier to operate. Nomenclature a — acoustic speed M = Mach number p = pressure Pij = Pi/Pj, pressure ratio Pi,j = Pt/Pj ~ 1 u = velocity T = temperature 7 = specific heat ratio Subscripts o = stagnation conditions 1, 2, 3,... = regions in wave diagram corresponding to different gas states CJ = Chapman-Jouguet s = shoc