I. Introduction

The simulation of the motion of various objects in Earth and planetary atmospheres requires the creation of gasdynamic facilities capable of providing flows with Mach numbers of M = 8 25 and Reynolds numbers of Re = 10 ⁶ 10 ⁸. Simple estimations prove that it is a hopeless task to duplicate completely all parameters of the flow around a real object in ground-based facilities, at least partly because of vast energy expenditures the power needed to create a flow 1 m in diameter reaches 800 MW (Ref. 1).

An effort to obtain long-term stationary flows for Mach numbers up to 10 was implemented in the T-117 blowdown wind tunnel at TsAGI.2 The large size of its test section (approximately 1 m) allows testing of models of a suitable scale there, including engine models. Unfortunately, relatively low initial pressures of the test gas (approximately 200 atm) do not provide complete simulation of Reynolds numbers for many problems. Moreover, T-117 shares the common drawbacks of all wind tunnels with electric-arc heating. These are related to the plasma generator producing stagnation temperature fluctuations, which under expansion lead to noticeable velocity oscillations considerably affecting the...