On supersonic and subsonic diffusers for magnetohydrodynamic generator applications
Abstract
Experimental investigations were made of both supersonic and subsonic diffusers with coal combustion gas (for MHD generator applications) with high entrance boundary layer blockage factors in the subsonic diffuser. It was found that a constantarea supersonic diffuser performed adequately. The pressure recovery is approximately 0.6 of the normal shock recovery with a diffuser length of approximately 70 percent of generator channel length. The subsonic diffusers have a maximum pressure recovery coefficient of 0.76 with an inlet blockage factor (B) of 0.16, which decreases to 0.6 at a higher blockage factor of 0.20, with 6 deg half angle. A quasionedimensional analysis with friction, heat transfer and chemical reaction predicts well the pressure and heatflux distribution in the channel, supersonic diffuser, and subsonic diffuser with small divergence angles. At large divergence angles, experimentally determined correction factors are applied.
 Publication:

Fluids Engineering in Advanced Energy Systems
 Pub Date:
 1978
 Bibcode:
 1978feae.proc..139R
 Keywords:

 Diffusers;
 Magnetohydrodynamic Generators;
 Pressure Recovery;
 Subsonic Flow;
 Supersonic Diffusers;
 Boundary Layer Flow;
 Chemical Reactions;
 Coal Utilization;
 Energy Technology;
 Flow Resistance;
 Heat Transfer;
 Inlet Flow;
 Pressure Distribution;
 Plasma Physics