AbstractLaser thermal propulsion refers to a concept in which power from a laser is beamed to a vehicle, where it is absorbed and used to heat a propellent gas that produces thrust at high values of specific impulse. The success of the concept depends upon the ability to create laser sustained plasmas that are stable in the presence of a forced convection flow and that absorb essentially all of the incident laser radiation. In addition, the thermal radiation losses from the plasma must be controlled to realize high performance without the penalty of thermal radiators. Extensive experiments have been performed and analyzed utilizing plasmas sustained in flowing argon by a carbon dioxide laser of less than 1 kW incident power. Spatially detailed measurements of the temperature in the plasmas have resulted in a detailed understanding of the energy conversion processes occurring within the plasma. This understanding has provided an explanation of the limited range of pressure and power observed for stable operation of laser sustained plasmas and suggests the means by which that range can be extended. A computational model based on a Navier-Stokes description of the flow has been developed which utilizes ray tracing for the optical interaction and temperature dependent transport and thermodynamic properties for the plasma. This model has been verified using the detailed experimental results for the argon plasmas and has been extended to provide predictions for higher laser powers in hydrogen.
Laser thermal propulsion using laser sustained plasmas
Acta Astronautica ; 15 , 6-7 ; 367-376
1987-01-06
10 pages
Article (Journal)
Electronic Resource
English