RESEARCH ON NEW CONCEPTS IN ENERGY CONVERSION.
Abstract
The principal result of the investigation is that, near open circuit, the dominant loss in the large, supersonic nonequilibrium MHD generator studied here is due to shorting by the end loops. The loss is more severe than in equilibrium generators because the ends are coupled to the active section of the generator by layers of highly conducting gas along the electrodes. A simple model based on these ideas explains the variations of transverse and axial electric fields along the generator's length. One result of the comparison of the model with the data is an estimate for the effective bulk Hall parameter. It varies from unity to 1.6 as the microscopic Hall parameter varies from 4 to 5.4. The effective value may be determined by electrothermal wave instabilities. The axial short induced by the electrode wall-end loop mechanism is so severe as to prevent the generator's producing more than a tiny fraction of its ideal Hall field. Thus, it behaves essentially as a continuous electrode generator. As such, it has induced conductivities near short circuit which are at least 5 times those that are possible without nonequilibrium ionization. A possible cure for the shorting is to extend the magnetic field far forward and aft of the active section. Another is to quench the conductivity at the exit of the active section. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 15, 1967
- Accession Number
- AD0824666
Entities
People
- J. L. Kerrebrock
Organizations
- Massachusetts Institute of Technology