03.3 - Basic Fluid Dynamics and Flow Control
DIRECT NUMERICAL SIMULATION OF MACH WAVE INFLUENCE ON LAMINAR-TURBULENT TRANSITION IN SUPERSONIC FLOW OVER A FLAT PLATE
I.V. Egorovš, A.V. Fedorovš, K.H. Ding, Central Aerohydrodynamic Institute, Russia; šTsAGI, Russia
In this work influence of N-wave, generating by two-dimensional roughness on the side wall of the wind tunnels working section, on laminar-turbulent transition, induced by increase and nonlinear breakdown of the first mode in boundary layer on the flat plate at free stream Mach number 2.5, is studied using direct numerical simulation on basis of Navier-Stokes equations. Disturbances, corresponding to the first mode, are artificially excited in boundary layer using periodical injection-suction of gas through the narrow part of the surface. It is shown that disturbances, induced in boundary layer by the back front of N-wave, have no influence to transition onset, but shift nonlinear stage of the first mode development downstream; disturbances, induced by the leading front of N-wave, shift transition onset upstream.