Force and moment measurements on the HOPPER configuration for high enthalpy conditions

Abstract

TH2-D is a high enthalpy hypersonic wind tunnel, for this test campaign driven by an upstream detonation driver [1]. An oxyhydrogen detonation in the high pressure section generates a shock wave in the low pressure section, compressing and heating the synthetic air used as test gas. Varying the filling pressures in both sections and/or diluting the stoichiometric oxyhydrogen with different percentages of helium or argon yields different test conditions. Table 1 shows the test conditions employed corresponding to two points of the HOPPER re-entry trajectory [2]. Figure 1 illustrates reservoir and pitot pressure (p₀, p_t2) as well as the stagnation point heat flux $\dot q_{t2}$, as a measure for the stagnation enthalpy. The nozzle flow is protected from water vapour contamination after the testing time by a fast acting center plug valve. The conical nozzle with a half apex angle of 5.8° is followed by the test section with a usable length of about 400 mm and a core flow diameter of 400 mm.