Techniques For Measurement Of Dynamic Stability Derivatives In Ground Test Facilities PDF Download

Wind tunnel tests were conducted to provide sting-support interference information for planning and directing wind tunnel tests at subsonic and transonic Mach numbers. Sting-length effects on dynamic stability derivatives, static pitching moment, and base pressure of a blunt, flat-base 7- deg cone were investigated at Mach numbers 0.2 to 1.3 in the Arnold Engineering Development Center (AEDC) Propulsion Wind Tunnel Facility (PWT). Two frequencies of oscillation, nominally 5.3 and 2.9 Hz, were investigated. The boundary-layer state at the model base was turbulent for all Mach numbers greater than 0.2. The interference effects of two types of model-wake splitter plates were also investigated. The results showed that the critical sting length depended on the Mach number, angle of attack, and type of data used as the interference indicator. A critical sting length of three model diameters was determined to be suitable for all test conditions for the ratio of sting-diameter-to-model-base- diameter (0.22) for this test.