Force measurements on a circular cylinder in a Cryogenic Ludwieg-Tube using piezoelectric transducers

Abstract

Force and pressure measurements were performed in a high Reynolds number facility, i.e. the Cryogenic Ludwieg-Tube (KRG). The balance based on multicomponent piezoelectric force transducers was applied totally in the cryogenic environment. The behaviour of the balance was tested ranging from ambient down to cryogenic conditions. As test cases, the flow around a circular cylinder was investigated at a sub- and supercritical Mach number. The highest possible Reynolds number in most nearly incompressible flow (Re = 5.8 × 10^6) was achieved at the temperature of T = −150°C, the highest pressure possible, p 0 = 10 bar, and the lowest attainable Mach number of Ma = 0.28. The results show that, in spite of the pulse operating mode of the tunnel, the steady and unsteady processes can be measured very well by means of a piezoelectric balance.