Salvatore ESPOSITO, Antonio SCHETTINO, Luigi CUTRONE, Domenic D’ AMBROSIO
DOI Number: N/A
Conference number: HiSST-2025-244
Plasma formation in hypersonic reentry flows affects electromagnetic wave propagation, with direct implications for vehicle communications and radar signature. Accurate prediction of ionization is therefore essential to quantify these effects. This work presents a numerical analysis of electron density under the examined flight conditions of the RAM-C II vehicle using the in-house solver NExT, compared against CFD++ results and flight measurements. The simulations solve the compressible Navier–Stokes equa-
tions for a multicomponent, chemically reacting air mixture in thermal and chemical nonequilibrium, incorporating a multi-temperature model for vibrational energy. The influence of chemical kinetics, vibrational–chemical coupling, and surface catalyticity is systematically assessed. Among the tested kinetic schemes, Park’85 consistently overestimates electron concentrations, whereas Park’93 and Kim achieve closer agreement with experimental data. Surface boundary conditions also affect results, with a hybrid
approach—non-catalytic for neutral species and catalytic for charged species—producing the most consistent match with experimental data. Differences between NExT and CFD++ are most pronounced at the lowest and highest altitudes, whereas chemical kinetics and wall treatments affect electron density predictions across the examined flight conditions. The study provides a quantitative evaluation of modeling assumptions in hypersonic plasma simulations, supporting the application of NExT to reentry flow analyses where plasma–electromagnetic interactions are relevant.