Drag balance for hypervelocity impulse facilities

A new technique is described for measuring drag with 100-/*s 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 a cone with 15-deg semivertex angle in nominally Mach 5.6 flow with stagnation enthalpies from 2.6 to 33 MJ/kg. Measurement repeatability of about 10% is achieved.

[1]  B. Hopkinson.  A method of measuring the pressure produced in the detonation of high explosives or by the impact of bullets , 1914 .

[2]  Brian W. Stump,et al.  The determination of source properties by the linear inversion of seismograms , 1977, Bulletin of the Seismological Society of America.

[3]  Sawasd Tantaratana.  Two-Stage CFAR Detectors for Multiple-Range-Bin Radars , 1983, IEEE Transactions on Aerospace and Electronic Systems.

[4]  M. J. R. Healy,et al.  Multichannel Time Series Analysis with Digital Computer Programs. , 1978 .

[5]  C. T. Kidd,et al.  Recent Developments in Heat-Transfer-Rate, Pressure, and Force Measurements for Hot-Shot Tunnels , 1968, IEEE Transactions on Aerospace and Electronic Systems.

[6]  C. C. Horstman,et al.  Cone drag in rarefied hypersonic flow , 1969 .

[7]  H. Kolsky.  An Investigation of the Mechanical Properties of Materials at very High Rates of Loading , 1949 .

[8]  Bruno O. Shubert,et al.  Random variables and stochastic processes , 1979 .

[9]  Geoffrey Ingram Taylor,et al.  The Air Pressure on a Cone Moving at High Speeds. II , 1933 .

[10]  Leonard Bernstein,et al.  A Laser-Interferometric Trajectory-Following System for Determining Forces on Freely Flying Models in a Shock-Tunnel, , 1981 .

[11]  George R. Duryea,et al.  An Improved Piezoelectric Balance for Aerodynamic Force , 1968, IEEE Transactions on Aerospace and Electronic Systems.

[12]  Jennifer E. Michaels,et al.  The inverse source problem for an oblique force on an elastic plate , 1985 .

[13]  H. Saunders,et al.  Finite element procedures in engineering analysis , 1982 .

[14]  Jacques Beaussier.  A Six-Component Balance , 1968, IEEE Transactions on Aerospace and Electronic Systems.