Acoustic and entropy waves in a combustion MHD generator
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 phenomena, 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. Inside the generator, transient measurements were taken at three locations using 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. The pressure waves in a laboratory scale generator are not appreciably affected by MHD phenomena, as anticipated from analytical predictions. Temperature 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 currents are absent. These data are explained by a model for secondary flows which affects heat transfer from the plasma. Application of a model for the magneto-acoustic phenomena in large scale MHD generators indicates that property fluctuations may grow appreciably if the electrical resistance in the electrode boundary layers is small with respect to the resistance of the plasma core.
- Research Organization:
- Stanford Univ., CA (USA). High Temperature Gasdynamics Lab.
- DOE Contract Number:
- AC01-80ET15611
- OSTI ID:
- 5270441
- Report Number(s):
- DOE/ET/15611-T5; HTGL-203; ON: DE82017155
- Resource Relation:
- Other Information: Thesis. Portions of document are illegible
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
MHD CHANNELS
MAGNETOACOUSTIC WAVES
PLASMA INSTABILITY
MHD GENERATORS
COMBUSTION PRODUCTS
COMBUSTION WAVES
ELECTRIC CURRENTS
ELECTRIC POTENTIAL
FLOW MODELS
FLUCTUATIONS
HEAT TRANSFER
MATHEMATICAL MODELS
PLASMA
SOUND WAVES
SPATIAL DISTRIBUTION
CURRENTS
DIRECT ENERGY CONVERTERS
DISTRIBUTION
ENERGY TRANSFER
HYDROMAGNETIC WAVES
INSTABILITY
VARIATIONS
300104* - MHD Generators- Duct Engineering & Fluid Dynamics