Energy Losses from a Heated Air Column
Abstract
Estimates are made of the energy losses from the hot channel produced by (laser-guided) electric discharges in the atmosphere. The loss processes considered are heat conduction, continuum radiation, and line radiation. For the conditions calculated to exist in such channels (Te approx. 20,000 K, sigma (i) N (i) equal 2x10 to the 18th power c per cu.cm), the total energy loss is found to be small compared to the measured energy input ( approx. 3 J/cm along the length of the channel). Therefore the assumption of negligible losses used to calculate the channeled conditions is valid and the expansion of the hot channel will be adiabatic except where compressional shock waves are involved. Since the dominant energy loss is through optically thick line radiation and this loss is strongly temperature dependent, such radiation effectively limits the temperature to which the air can be heated to approximately but less than 20,000 K.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 17, 1982
- Accession Number
- ADA114757
Entities
People
- Joseph R. Greig
- Michael Raleigh
- Richard F. Fernsler
Organizations
- United States Naval Research Laboratory