Direct measurement of skin friction in hypersonic wind tunnel

The experiments of direct measurement of skin friction in hypersonic wind tunnels FD-03 and FD-07 of CAAA are introduced.Two-component and one-component strain-gage bal-ances are developed to the application of moving compression ramp experiment and wave rider ex-periment,respectively.In the experiments,the total pressure is 1MPa,total temperature is 360K and Mach number is 5.There are two balances installed in each model as measuring points. In the moving compression ramp experiment,the skin friction of plate is measured.The flow field is found to be interfered by the moving compression ramp,and the skin friction of the com-pressed ramp motion interference region is measured.In the wave rider experiment,the skin fric-tion of the model is measured and the relationship between the skin friction and the angle of at-tack has been found.Temperature correction is introduced to the experimental data processing. In all the experiments,the uncertainty is less than 1 2%.