Structural Waveguides for Aerodynamic Turbulent Drag Reduction

摘要

The objective of this project was to provide a proof-of-concept that travelling wave disturbances on the surface of a vehicle can generate viscous drag reduction benefits. This would be accomplished by developing structural waveguides within a cylinder that under actuation impart a structural surface wave disturbance in the form of a travelling wave. During the nine month performance of the work presented herein we were successful indesigning and fabricating structural waveguides. Structural characterization of the prototype demonstrates that the performance met the design expectation. Subsequently, initial aerodynamic testing was performed in order to validate that the proposed concept can impart flow disturbances that reduce turbulent viscous drag. At the time of this report only quantitative flow visualization under quiescent flow conditions had been performed and preliminary analysis of the results is presented. The PIV results showed a three stage cycle occurring, which creates a motion that sweeps the flow very close to the wall in a clockwise direction. This movement of fluid might interrupt the near-wall turbulence production.