A drag measurement technique for free piston shock tunnelsA new technique is described for measuring drag with 100-microsecond rise time on a nonlifting model in a free piston shock tunnel. The technique involves interpretation of the stress waves propagating within the model and its support. A finite element representation and spectral methods are used to obtain a mean square optimal estimate of the time history of the aerodynamic loading. Thus, drag is measured instantaneously and the previous restriction caused by the mechanical time constant of balances is overcome. The effectiveness of the balance is demonstrated by measuring the drag on cones with 5 and 15 deg semi-vertex angles in nominally Mach 5.6 flow with stagnation enthalpies from 2.6 to 33 MJ/kg.
Document ID
19910034733
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Sanderson, S. R. (Queensland Univ. Saint Lucia, Australia)
Simmons, J. M. (Queensland, University Brisbane, Australia)
Tuttle, S. L. (Queensland Univ. Saint Lucia, Australia)