Experimental-Computational Study of Gas-phase and Gas-surface Interactions for High Speed Rarefied Flow
Abstract
This proposal describes the fundamental scientific challenges associated with gas-phase and gas-surface interactions for high speed rarefied flow. This flow regime is important for very high altitude flight that is too high for air-breathing subsonic and supersonic engines to operate, yet far too low for satellites to orbit. If aircraft, rockets, or spacecraft fly through such high altitudes, it is only for a brief time (seconds) on the way up or on the way down. Efforts continue to operate aircraft at higher altitudes and orbit satellites at lower altitudes, however, there are significant challenges to understand gas-phase and gas-surface interactions under these conditions. The atmospheric density is low and rarefied flow effects become important. Furthermore, above 100 km, the composition and temperature of the atmosphere change drastically. Both novel simulations and novel experiments are required to understand aerothermodynamics in this new flight environment. At low densities, molecular-level interactions between the gas and vehicle materials become important. This is an unexplored design space where novel materials may reduce drag and heat flux; however, they must be resistant to high energy O atom impacts. Furthermore, at high altitudes the most abundant gas species is atomic oxygen. These atoms are highly reactive and surface chemistry under low pressure conditions requires investigation. In particular, surface recombination (surface catalysis) could be a dominant reaction.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 29, 2024
- Source ID
- FA95502310162
Entities
People
- Thomas Schwartzentruber
Organizations
- Air Force Office of Scientific Research
- Regents of the University of Minnesota
- United States Air Force