Numerical Simulation Of Magnetohydrodynamics

Abstract

Use of electromagnetic fields has been shown to be an effective way to control the behavior of electrically conducting fluids. Specifically, the modification of the boundary layer profile with electromagnetic fields can yield performance improvements such as reduced drag and improved heat transfer. Though this approach has been demonstrated computationally and experimentally with conducting liquids (i.e. seawater), application to aerodynamic devices operating in air has not seen the same success. Through the use of numerical simulation and eventually optimization, we hope to develop efficient designs that are effective for boundary layer control for low temperature conducting gases (non-thermal plasmas). The boundary layer control technique requires an electrically conducting fluid within the boundary layer and either intense magnetic fields or high voltage difference across electrode pairs. The plasma discharge at atmospheric pressure was suggested to ionize air and thus increase the electrical conductivity of the air. A numerical model was developed to assist in the design of physical experiments and to enhance the understanding of the physical mechanism of the plasma flow under the influence of electromagnetic fields. The model equations governing the flow of non-thermal plasmas in an electromagnetic field were discretized using finite volume method for MHD fluid equations and Galerkin finite element method for MHD electrodynamics equations on an unstructured mesh. It was observed that flows at low Reynolds number can be altered by electromagnetic fields with low applied voltage and relatively low magnetic flux density under the assumption of constant electrical conductivity of plasma.