On water-vapor plumes, condensation, and their effect on laser propagation in the laser propelled rocket
Abstract
This paper investigates condensation and absorption of CO2 laser radiation in water vapor plumes at various altitudes with specific application to laser propulsion of rockets. Both absorption by water vapor and absorption/scattering by water droplets are considered. At high altitudes the plume was modeled as an expansion into vacuum; the expansion leads to cooling and condensation. Absorption both by condensed water droplets and by water vapor was found to be negligible (about 10 to the -4th to 5 x 10 to the -4th). At intermediate and low altitudes (not greater than 20 km) the plume cools by entraining ambient air. It is found that for typical engine conditions condensation is unlikely if the ambient air is dry, except possibly for a small altitude range near 12 km. Absorption by water vapor was found to be negligible at 20 km and small at sea level.
- Publication:
-
American Institute of Aeronautics and Astronautics
- Pub Date:
- June 1977
- Bibcode:
- 1977fpd..confR....W
- Keywords:
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- Carbon Dioxide Lasers;
- Laser Applications;
- Photonic Propulsion;
- Rocket Propellants;
- Water Vapor;
- Condensation;
- Drops (Liquids);
- Electromagnetic Absorption;
- Plumes;
- Rocket Nozzles;
- Lasers and Masers