Turbulent boundary layers as affected by weak magneto-hydrodynamic forces

The integral technique reported by Lessmann and Christoph (1975) for calculating turbulent skin friction is extended to include the effects of weak MHD forces. The analysis concerns the equation of motion for steady two-dimensional turbulent boundary-layer flow in the presence of a uniform transverse magnetic field for the case of small magnetic Reynolds number. The approach used in the analysis presented is to nondimensionalize the momentum equation using law-of-the-wall variables and integrate across the boundary layer. Since the analysis includes pressure gradient effects, several sample calculations for different pressure gradient flows at different values of the interaction parameter are presented. The product of the interaction parameter and the Reynolds number represents the ratio of the magnetic pressure to the dynamic pressure. This product must be of order one for the magnetic fields to have a significant effect.