Publication

Abstract : Accelerometer based force balance system is a common technique used in shock tunnels to measure aerodynamic forces over models. This internally mountable force balance has rubber bushes, which facilitate an unrestrained movement of the model during the short test times of the tunnel. In some particular model-balance systems, when there are high energy flows, we may find the rubber bushes used in those balance systems shearing out. However, the behaviour of these rubber bushes on the predetermined acceleration history is not much familiar. To find out the effect of rubber bushes, a numerical approach is explored. An unsteady analysis of the flow through the shock tunnel and a blunt body has been carried out first. Finite element analysis is then executed to predict the acceleration and this value is analysed with that of the experimental value of acceleration. The prediction of acceleration values for different blunt bodies can be made with these results with different flow conditions and also for different angles of attack. © 2017 Pushpa Publishing House, Allahabad, India.