Roughness and turbulence effects on the surface pressure over yawed cylinders

A mean and fluctuating surface pressure analysis over both smooth and rough 45-deg yawed circular cylinders in low and moderate turbulent freestreams are presented. Results from mean pressure distributions indicate that infinitely long model conditions are established away from the disturbance of the free end. With the exception of the turbulent flow results, fluctuating pressure distributions show flow conditions not independent of span, suggesting that both mean and unsteady flow characteristics must be considered if infinitely long model conditions are required. Increasing freestream turbulence was found to promote infinitely long circular cylinder results, whereas surface roughness was found to produce highly asymmetric, unsteady flow results.