Aerodynamics of a chined forebody oscillating in pitch
A low-speed experimental study of the effects of an oscillatory pitching motion on the flowfield of a chined forebody has been performed. These tests were conducted in the University of Illinois low-speed (0-240 ft/sec), low-turbulence ($<$0.1%), 3 by 4 ft, open circuit wind tunnel. The high fidelity, NC machined aluminum model was sting mounted and oscillated sinusoidally in pitch from 0$\sp\circ$ to 52$\sp\circ$ angle of attack without sideslip. The effects of reduced frequency as well as free-stream Reynolds number were investigated by running a range of tunnel velocity/model oscillation frequency combinations. Reynolds numbers, based on the 3-inch base diameter of the forebody, of 1.4 x 10$\sp5$ to 2.8 x 10$\sp5$ were tested. The experiments cover a range of oscillation frequencies from 0 to 1 Hz, corresponding to reduced frequencies, based on the 10.5-inch length, of 0 to 0.0275. Surface pressures were measured at all conditions using an array of 91 static pressure taps. Normal force and pitching moment were determined by integrating these data. Surface oil and smoke flow visualization were utilized to determine the vortex system and help interpret the surface pressure data.
Engineering, Aerospace, Engineering, Mechanical
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign