Katsuhiro Itoh

Numerical study of free-piston shock tunnel performance

A free-piston shock tunnel (FPST) is one of the most useful ground testing facilities for hypervelocity flow research of re-entry vehicles and scramjet engines. For an efficient operation with tuned piston motion, the design of facility and the comprehension of the physical phenomena in a FPST, a numerical simulation which can properly predicts the flow with actual losses is required. But there are few successful numerical methods which can simulate its overall performance. In the present study, numerical method was developed by using the KRC shock capturing scheme and by modeling the flow losses in suitable forms for a quasi-1D numerical computation. The present numerical results were compared with the data obtained in two different facilities, T4 and T5. The applicability of the present numerical method as a design tool is discussed briefly.

A Numerical and Experimental Study of the Free Piston Shock Tunnel

In the present study, a CFD-aided tuned operation of a free piston shock tunnel (FPST) was proposed. For that, a numerical method which can accurately predict characteristics of a FPST was developed by using a 4th order pointwise non-oscillatory scheme and models of the flow losses. The tuned operation condition for the FPST of the Shock Wave Research Center(SRC-FPST) at the Institute of Fluid Science, Tohoku University was estimated from the parametric calculations with the present numerical method. The experiments were conducted at the condition, in which the stagnation enthalpy and pressure were 10.6 MJ/kg and 570 atm, respectively. The test flows were observed by holographic interferometry.