Drag and heat transfer in azimuthally oscillating turbulent pipe flow

Experiments are preformed to investigate the effects of transverse momentum injection on the drag and heat transfer of fully developed turbulent pipe flow. A driving system consisting of a crank-slider mechanism is employed to oscillate the pipe azimuthally, so that the spanwise wall velocity is varying sinusoidally in time. Pressure and temperature gradients along the oscillating pipe are measured to determine drag and heat transfer, respectively, and the results are compared to the power consumption of the driving system to characterize the overall energy efficiency. Results will be discussed for two friction Reynolds numbers of approximately 4000 and 8000.