A skin-friction balance for shock tunnel applications

Abstract

Abstract An acceleration-compensated skin-friction balance based on the floating-head technique was developed to measure skin friction in a hypersonic impulse facility. The balance consisted of measurement and acceleration units, the outputs of which can be coupled using a full-Wheatstone bridge to obtain pure shear output. The working of the balance was tested on a flat plate model exposed to a laminar flow with Mach number, stagnation enthalpy and Reynolds number of 8.2, 0.65 MJ kg−1 and 2.9 × 106 m−1, respectively. The measured wall shear stress agreed reasonably well with that predicted by Reynolds analogy.