Turbulent drag characteristic of small amplitude rigid surface waves
Abstract
The paper discusses an experimental and theoretical investigation of low speed turbulent flow over transverse rigid wavy surfaces having a wavelength on the order of the boundary layer thickness. In addition the results of theoretical investigations of laminar flow over short wavelength waves and turbulent flow over long wavelength (wavelength much greater than the boundary layer thickness) wavy walls are presented. Surface pressure and net drag measurements obtained for the short wavelength symmetric and asymmetric waves in a turbulent flow agreed with the results obtained with a NavierStokes spectral code and indicated no significant drag reduction. Several asymmetric wave configurations did significantly reduce the pressure drag compared to sine wave geometries, but these waves still did not produce a net drag reduction. The NavierStokes calculations for laminar flow indicated a drag reduction of up to 17 percent for certain short wavelength waves. Boundary layer calculations for turbulent flow over long wavelength surface waves indicated that net drag reductions on the order of 10 percent may be possible for largeradius waisted bodies.
 Publication:

AIAA, Aerospace Sciences Meeting
 Pub Date:
 January 1983
 Bibcode:
 1983aiaa.meetR....L
 Keywords:

 Drag Reduction;
 Pressure Drag;
 Skin Friction;
 Surface Roughness Effects;
 Surface Waves;
 Turbulent Flow;
 Computational Fluid Dynamics;
 Pressure Distribution;
 Rigid Structures;
 Sine Waves;
 Small Perturbation Flow;
 Viscous Drag;
 Fluid Mechanics and Heat Transfer