High-enthalpy hot-shot wind tunnel with combined heating and stabilization of parameters

Abstract

In the present paper, we consider instrumentation and the experimental procedure for conducting tests in a highenthalpy short-duration wind-tunnel facility, namely, a hypersonic hot-shot wind tunnel. We consider operation of the hot-shot wind tunnel with the test gas (TG) parameters kept constant during the regime and also operation of the tunnel as a traditional shock tube with a decay of the TG parameters that occurs as the TG leaves a constant-volume settling chamber. Stabilization of the TG parameters is achieved by using a pressure multiplier installed coaxially with the settling chamber, the configuration presenting a linear arrangement of the two components. Unloading of pressure multiplier dynamic component is achieved by using an equalizer whose piston moves in the opposite direction to the multiplier piston system. Several modes of wind tunnel operation with various combinations of different TG heating methods (electric arc, chemical energy, adiabatic compression, or heating in an external with respect to the settling chamber heat source) are possible. The design of a device responsible for diaphragm breakdown delay is considered. The design and dimensions of the wind tunnel provide for its normal operation under the following conditions: range of Mach numbers M = 4–20, range of settling-chamber temperatures T _ch1 = 600–4000 K, and settling-chamber pressure p _ch1 up to 200 MPa (in operation with a double settling chamber, the stagnation pressure p _0n = p _ch2 can be varied from 1 to 200 MPa). The settling chamber volume (80–100 dm³) is sufficiently large, allowing obtaining a 1-m diameter hypersonic stream in the test section during ∼ 100 ms (in combination with a second settling chamber).