Contrôle de la couche limite laminaire d’un écoulement stationnaire, visqueux, compressible et subsonique autour d’un profil bidimensionnel

Abstract

A numerical study of a laminar boundary layer of a stationary, viscous, compressible and subsonic flow around a two-dimensional NACA profile was conducted without and with control. The flow domain has been divided into two zones, one near-wall, the boundary layer, which is responsible for friction phenomena, and the other, an external zone where flow is considered potential. The potential flow is studied by the panel method for the determination of the external velocity distribution necessary for the treatment of the boundary layer. The boundary layer was studied using the PRANDTL model and the KELLER method by reducing the order of the first-order differential equations, the writing of the algebraic equations, and the linearization by the Newton method via an iterative calculation process and finally the resolution by the method of elimination by blocks. The distributions of the pressure and lift coefficients were determined and examined for different Mach numbers and different angles of attack with varying relative thickness. Thermal control by wall heating or wall cooling was studied and the results demonstrated only the effectiveness of the wall cooling control on the recoil of the separation point around 10% of the chord of the profile. The dynamic control by suction or blowing has demonstrated its effectiveness on the decline of the separation point; the decline has reached 10% of the chord of the profile. The superimposition of the thermal and dynamic control procedures demonstrated once again more efficiency on the retreat of the boundary layer separation point with a gain of 15% of the chord of the profile.