Drag Measurements in a Stream with Sinusoidally Fluctuating Velocity in the Longitudinal Direction

摘要

The drag coefficients of cylinders and plates in a stream with sinusoidal fluctuations in velocity are investigated. A tube with counterrotating vanes at the rear is used to produce the flow fluctuations. This tube was placed in the open jet of a low speed tunnel. The models were mounted on a vertical sting, which supported the one-component force transducer. The drag coefficients, based on average values of drag and dynamic pressure, show no variation with frequency parameter changes. The fluctuating component of drag does show a dependence on the frequency parameter. Also, a phase shift is noticed between the velocity and the force. (Author)