Unsteady Pressure Measurements on Scaled Configurations of ASLV

Unsteady pressure measurements were carried out, on the scaled configurations of Augmented Satellite Launch Vehicle (ASLV)Measurements were confined to the heatshield region and flare region of the vehicle . Measurements in the cylindrical region of the heatshield indicate presence of the unsteady flow due to shock wave oscillations in the Mach number band of 0.84 to 0 having dominant frequencies at 38Hz,61i &95 riz_ In the boat-tail region, the amplitude of pressure fluctuations due to shock oscillations are considerably lower as compared with those observed on the cylindrical region. Analysis of measurements in the flare region which were carried out at M = 1.8, 2.1 and 2.5 indicates the presence of unsteady flow with dominant frequencies at 875Hz and 1750Hx . An increase in the amplitude of pressure fluctuations is observed in the region of shoulder where the booster shock interacts with the f low on the core vehicle