Power Generation Characteristics of Disk-Shaped Magnetohydrodynamic Generator Driven by Rotating Detonation

The power generation characteristics of a disk-shaped magnetohydrodynamic generator driven by rotating detonation with potassium-seeded hydrogen-air mixture are examined via quasi-two-dimensional numerical simulations. For unburned gas injection in the outward and inward directions, the rotating direction of the detonation wave is set so that the azimuthal velocity enhances the radial electromotive force. The simulation results show that the power output in the outward flow configuration exceeds that of the inward flow configuration. In the outward flow configuration, the radial gas velocity around the contact surface is the main contributor to the power generation, while in the inward flow configuration, the low gas velocity in almost the entire region and the vortices around the contact surface lead to poor power output. The characteristics in not only the power output mode but also the power input mode in which the voltage is applied externally between the electrodes are investigated. Under the positive load voltage, high enough for providing negative current, the Lorentz force occurs in the same direction as the propagation of the detonation wave; otherwise, the Lorentz force is induced in the opposite direction of the detonation wave.