Plasma-Wall Heat Transfer in Electrodeless Radio-Frequency Discharges
Abstract
Alternative propulsion technologies and propellants have become important research topics within the space industry in recent years because of evolving mission needs, emerging interest in on-orbit refuelling, and the future strategic importance of in-situ resource utilization from the Moon, Mars, or asteroids. One novel proposed propulsion technology is a Radio-Frequency (RF) electrothermal plasma thruster, which makes use of an inductive RF coil to superheat propellant gas to temperatures as high as 10,000 oC. Thrust is then generated as the hot gas is accelerated through a converging-diverging nozzle. Although previous experimental work has validated this propulsion concept, the high-temperature plasma-gas environment produces strong heat losses to the thruster walls which currently represents a technical barrier to further technology development and adoption. Detailed plasma-wall heat loss measurements are however challenging because of difficulties associated with diagnostic access in actual thrusters, having complete control of all operating and thermal conditions, and the wide range of possible propellants. The main objective of this research project is to develop a reference RF plasma source and to use it to perform fundamental heat transfer studies with a range of different propellants (including argon, nitrogen, and water vapor). Heat transfer will be directly quantified use calorimetry techniques, while important plasma-gas properties (such as temperature, density, and discharge composition) will be inferred from a series of non-invasive diagnostics, such as optical emission spectroscopy. The outcomes of this project will provide an important foundation for the development of practical future devices for both space- and ground-based applications.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 06, 2025
- Source ID
- FA23862514011
Entities
People
- Trevor Lafleur
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of New South Wales