Abstract

No abstract

No abstract

No abstract

No abstract

This paper studies the similitude between the 3D cellular patterns which appears in the simulation of transonic buffet and subsonic stall phenomenon using RANS/URANS simulations. These wings are obtained from the extrusion of a 2D airfoil with an added sweep angle and periodic boundary conditions imposed at both ends. This numerical setup allows to study three-dimensional buffet on the simplest configuration possible. Numerical solutions exhibit three-dimensional flows in the form of buffet cells. The latter are convected towards the wing tip when a sweep angle is added leading to the superposition of two frequencies. The first one is independent of the sweep angle and is characteristic of two-dimensional buffet. The second one increases with the sweep angle and is related to the convection of the buffet cells. These cells are reminiscent of the stall cells which are well-known but for low speed flow conditions. Solutions of the URANS equations for infinite swept wings in stall conditions at low speed are computed showing the same convection of the cellular patterns. These results lead us to think the discrepancies between 2D and 3D buffet are caused by the appearance of stall cells, which are the same as buffet cells, and not from a modification of the shock wave boundary layer interaction.

No abstract

No abstract