Normal force and pitching moment is experimentally obtained on a slender cylinder at two different angles of attack at several static positions and translating motions from within a cavity to outside Mach 1.5 freestream. Measurements reveal a constant normal force and pitching moment within the cavity at 0° and large variations throught the shear layer to the outside freestream. At 5° angle of attack, force and pitching moment has constant positive gradient from the cavity ceiling to the shear layer. Frequency spectra is relatively well predicted by Rossiter's second- and third modes, and overall high-content frequencies translated slightly to lower frequencies. Dynamic motions has good repeatability and exhibit a different unsteady force and moment trajectory from quasi-steady, even at a motion as slow as 1790 convective times.
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