Large-Eddy Simulation of a Turbulent Coanda Jet in an External Flow

Abstract

This work follows up a previous paper presented at the 28th International Symposium of Ballistics about the fluidic control of a 155 mm spin-stabilized projectile using the Coanda effect. A continuous jet is used to blow tangentially over a convex surface at the projectile aft end. Due to the balance between centrifugal forces and the radial pressure gradient, the jet attaches to the circular wall and generates significant aerodynamic forces. A large-eddy simulation of a highly simplified configuration is performed in order to acquire a better understanding of the physical mechanisms induced by the use of the Coanda jet. First, comparisons are performed with a similar work on a circulation control wing in order to validate the simulation. Then, the main effort focuses on the identification of existing vortices over the convex surface. Their natural frequencies and characteristic lengths are investigated through a spectral analysis.