A new 6-component acceleration compensated piezoelectric Force balance was designed, built and used to perform force and moment measurements on a 6-inch diameter Apollo shaped capsule in the 48-Inch tunnel at CUBRC in cold hypersonic nitrogen flows. Results were compared with CFD computations and measurements with a 3-component acceleration compensated strain gage balance under the same nominal flow conditions on the exact same aerodynamic model. Excellent agreement was found between the two methods as L/D was within 1.5% and pitching moment within 8%. Agreement with perfect gas Navier-Stokes computations was within 5% for all the measured aerodynamic coefficients. Compared to a previous strain balance gage design, the new piezoelectric balance has both frequency response and sensitivity increased by a factor of approximately four. The current design is expected to allow force measurement in the new LENS-XX expansion tunnel for test times as low as 1 ms. Simple modifications to the existing design should allow measurements for test times as low as 0.3 ms and force levels as high as 3000 lbf.
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