Stability theory and experiments in wall-turbulence

Abstract

Drag reduction is one of the most important areas of research. The main concept behind drag reduction is turbulence control. This could possibly be achieved in near wall turbulent flow by suppressing wall-mode instabilities (i.e., by interfering with the seeding mechanism of turbulence production). Wall-mode instabilities can be studied by applying hydrodynamic stability theory to wall bounded turbulent flows. It has been shown in Sen & Veeravalli, 2000 (Sadhana, 25, 423-437) that an anisotropic eddy viscosity model is crucial in capturing the wall mode instabilities. The main results of this theory are discussed and we present detailed experimental investigations carried out with the objective of verifying the Sen & Veeravalli theory