Influence of magnetic field inclination on flow stabilization and pressure loss in a U-bend MHD channel

This study numerically investigates magnetohydrodynamic flow in a U-bend channel with electrically insulating walls using the AnuPravaha code. The main goal is to understand how the inclination angle of the magnetic field ( θ ) and Hartmann number (Ha) affect flow stabilization and the associated pressure penalty. The results indicate that the pressure drop increases gradually with an increase in the inclination angle, and the effect is more pronounced with an increase in Hartmann numbers since the Lorentz force exerts greater electromagnetic resistance, resulting in a greater pressure penalty. The pressure distribution also changes significantly. At θ = 0°, it is highly non-uniform due to curvature-driven inertial effects, while at θ = 90°, it becomes nearly uniform, indicating that the magnetic field effectively suppresses inertial pressure variations. The non-uniformity of velocity, quantified by a global flattening index, consistently decreases with an increasing inclination angle, indicating that an increasing magnetic influence weakens the flow and creates a more plug-like velocity field, which is indicative of better flow stabilization. Velocity stabilization improves most noticeably between θ = 0° and θ = 45°, whereas further increases in inclination provide only small additional stabilization, but cause a larger pressure penalty. It is also found that an inclination angle of θ = 45° shows a more balanced stabilization gain, reaching up to 25% at higher magnetic field strengths, while maintaining the pressure penalty in a moderate range of 5.37% to 12.62%.