Two-dimensional acoustic instability in open-cycle supersonic disk MHD generator

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:254654

Matsuo, Tetsuji; Ishikawa, Motoo; Umoto, Juro ^[1]

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1. Kyoto Univ., Kyoto-Shi (Japan)

Both the guide vanes of the outflow disk MHD generator and the multiple inlets of the inflow disk MHD generator induce inlet azimuthal fluctuations, whose propagation along the channel may cause r-{theta} two-dimensional magneto-acoustic instability. The present paper evaluates the growth rate of r-{theta} two-dimensional disturbance during the propagation along supersonic disk channels by means of a sensitivity analysis. The generator analyzed here is a coal-fired outflow supersonic disk MHD generator of commercial scale. The paper proposes a method of sensitivity analysis for the azimuthally nonuniform disturbance. The sensitivity analysis shows that both low and high frequency two-dimensional disturbances have higher growth rate than one-dimensional ones. Time-invariant inlet azimuthal disturbances can tremendously grow during the propagation, which means that the fluctuation induced by the guide vanes may be quite dangerous. The azimuthal direction of traveling waves much affects the growth rate of waves. Two-dimensional time-dependent calculations also show that slight inlet azimuthal disturbances grow large during the propagation along the channel.

• OSTI ID: 254654
• Report Number(s): CONF-950697--
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
66 PHYSICS
COAL-FIRED MHD GENERATORS
DISK MHD GENERATORS
INSTABILITY
MHD CHANNELS
OPEN-CYCLE MHD GENERATORS
SENSITIVITY ANALYSIS
SUPERSONIC FLOW
TWO-DIMENSIONAL CALCULATIONS