European Conference on Computational Fluid Dynamics

ECCOMAS CDF 2006

P. Wesseling, E. Oñate, J. Périaux (Eds)

Ó TU Delft, The Netherland, 2006

COMPUTATIONAL STALL PREVENTION USING ELECTROMAGNETIC FIELDS

A. Sedaghat, A. R. Azimian and S. A. Akbari

Department of Mechanical Engineering

Isfahan University of Technology, Isfahan, Iran

e-mail: Sedaghat@cc.iut.ac.ir

Web page: http://www.iut.ac.ir

Key words: Electromagnetic Field, Lorentz Force, Flow Separation, Navier-Stokes, TVD Schemes.

Abstract. The dangers of exceeding stall margin for an aircraft wing or its engine are severe. Stall occurs at high angles of incidence where separation occurs over control surfaces. Separation may be controlled using magneto-hydrodynamics (MHD) techniques if the flow can be electrically charged. In this preliminary study, a flow solver was developed based on the governing Navier-Stokes equations for compressible flows. The flow solver uses an implicit, high resolution, and Total Variation Diminishing (TVD) scheme.  The flow solver was modified to include the effects of the electromagnetic field prescribed by Lorentz force. Two problems were investigated here. First, the separated subsonic flows are considered over a flat plate at high angles of attack. Second, an oblique shock wave leading to boundary layer separation is investigated for the flat plate in supersonic flows. For the case of subsonic flow, flow separation has been completely prohibited applying the electromagnetic field over the entire plate. The lift coefficient has been increased considerably. However, the overall drag coefficient has not been reduced noticeably. For the case of supersonic flow, the electromagnetic field was only applied in the vicinity of separated region in which it has been completely removed. Adequate amounts of the Lorentz force can be determined to evaluate feasibility of this technique for practical applications.