Algebraic growth in boundary layers: optimal control by blowing and suction at the wall

✍ Scribed by Patricia Cathalifaud; Paolo Luchini

• Book ID: 104373163
• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 257 KB
• Volume: 19
• Category: Article
• ISSN: 0997-7546
• DOI: 10.1016/s0997-7546(00)00128-x

✦ Synopsis

The upstream perturbations that maximise the spatial energy growth in a boundary layer are called optimal perturbations. The optimal perturbations correspond to streamwise vortices and the downstream response corresponds to streamwise streaks.

The aim of the present paper is to find a control by blowing and suction at the wall that zeros the energy of perturbation, when the initial disturbance is itself optimal. We shall also address the question: which kind of blowing and suction at the wall is most effective in controlling optimal disturbances?

The problem is examined by a method of receptivity analysis based on a numerical solution of a system of equations adjoint to the linearised boundary layer equations. We shall investigate both cases of a flat and a concave wall.