Acoustic and entropy waves in a combustion MHD generator

Thesis/Dissertation · Fri Jan 01 00:00:00 EST 1982

OSTI ID:6352485

Simons, T D

Simultaneous, sensitive, high frequency measurements of pressure and temperature fluctuations associated with traveling acoustic and entropy pulses were made in a combustion MHD generator under conditions of applied magnetic field (up to 2.2 Tesla) and moderate current density (up to 1.0 amp per square centimeter). The experimental observations and a closed form analytical description of the magneto-acoustic interaction suggest that non-ideal phenomena, including near electrode phonomena, heat transfer, and possible secondary flows can substantially inhibit wave growth or attenuation caused by magneto-acoustic instabilities. Disturbances in the plasma temperature and pressure were created by the rapid discharge of a capacitor into the moving conducting plasma. These disturbances propagated as pulses into the active generator. Inside the generator transient measurements were taken at three locations. At each location were a probe-tube microphone for pressure measurements, a fiber-optic luminosity probe for relative temperature measurements, and transverse mounted voltage pins to measure local voltage profiles along the generator sidewalls. The pressure waves in a laboratory scale generator are not appreciably affected by MHD phenomena, as anticipated from analytical predictions. Temperature (luminosity) waves are affected by the presence of magnetic field and current, showing small attenuation at low currents, greater attenuation at higher currents, and greatest attenuation when either or both magnetic field or currentes are absent.

• Research Organization: Stanford Univ., CA (USA)
• OSTI ID: 6352485
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
MHD GENERATORS
MAGNETOACOUSTICS
BOUNDARY LAYERS
COMBUSTION CHAMBERS
ELECTRODES
ENTROPY
HEAT TRANSFER
INSTABILITY
PLASMA
PRESSURE MEASUREMENT
TEMPERATURE MEASUREMENT
ACOUSTICS
DIRECT ENERGY CONVERTERS
ENERGY TRANSFER
LAYERS
PHYSICAL PROPERTIES
THERMODYNAMIC PROPERTIES
300100* - Direct Energy Conversion- MHD Generators