Numerical Investigation on Non-Uniformity in Channel Cross Section of Scramjet Driven Magnetohydrodynamic Power Generator

Hypersonic Vehicle Electric Power System (HVEPS) program, which is one of practical applications of Magnetohydrodynamic (MHD) electrical power generation, stated from 2001. Scramjet driven MHD electrical power generation experiments were conducted, and reasonable output electric power was successfully extracted. We carry out one-dimensional (1-D) in axial coordinate and steady-state three-dimensional (3-D) numerical simulations in order to explain experimental results. Hall potential distribution in the main part of generator channel agreed well with 1-D numerical results using adequate G-factor, which can introduce non-uniformity of conductivity and Hall parameter in cross section of the generator channel into the axial 1-D simulation. 3-D simulation could explain strong voltage drop in the inlet and exit region in spite of assuming 20%(=1/5) conductivity. Further, the effect of non-uniformity of gas temperature at the inlet was examined. Generator performance strongly depended on inlet non-uniformity both strength and structure. Direction of the structure of non-uniformity provided the opposite results of the output performance. We could conclude that the actual effects of non-uniformity of the working plasma on generator performance couldn’t explain simple G-factor.