Characterization of Supersonic and Subsonic Plasma Flows

Comparative Measurements of Earth and Martian Entry Environments in the NASA Langley HYMETS Facility

“…37. The normalized comparison establishes that L3K and the PLASMATRON agree to within 3% of each other for these test conditions 37 , indicating that HYMETS also compares favorably to the PLASMATRON facility by extension. Without normalization, the results for the PWK 1 and 2, and the COMETE facilities do not compare favorably with HYMETS.…”

“…An indirect comparison can be made by normalizing both subsonic and supersonic heat flux values by the method demonstrated in Ref. 37. The normalized comparison establishes that L3K and the PLASMATRON agree to within 3% of each other for these test conditions 37 , indicating that HYMETS also compares favorably to the PLASMATRON facility by extension.…”

High-enthalpy test environments, flow modeling and in situ diagnostics for characterizing ultra-high temperature ceramics

“…Previous investigations have shown that three parameters must be replicated to match stagnation point convective heating conditions in ground test facilities: (1) stagnation point enthalpy; (2) stagnation (or impact) pressure; and (3) velocity gradient at the boundary layer edge. 22,29 The velocity gradient is the rate that the velocity increases as gas flows around the test article. Thus, the convective heat transfer to the same test specimen exposed to arc-jet and ICP flows with similar free-stream enthalpy and total pressure values can be substantially different, owing to the large difference in velocity gradients between subsonic and supersonic test facilities.…”

Hypersonic Aerothermochemistry Duplication in Ground Plasma Facilities: A Flight-to-Ground Approach

“…This study was extended by Trimmer and Clark [13] to hypersonic flows on axisymmetric models with changing bluntness, and reached the same conclusion. Fletcher and Playez [14] use the velocity gradient scaling coefficients of Trimmer and Clark for hypersonic and subsonic flows as given in [15] for a blunt yet axisymmetric body and compared hypersonic and subsonic ground test facility measurements.…”