Chemical nonequilibrium ablation analysis of MUSES-C super-orbital reentry capsule

Analysis of Thermochemical Nonequilibrium in Post-normal Shock Flow of Nitrogen

“…Computational fluid dynamic results calculated by these temperature models show fairly good agreement with previous flight experiments [1]. However, in the studies of the intermediate hypersonic speeds between Mach numbers of 10 to 15 [2] and when the reentry velocity exceeds 10km/sec [3] in air, there exists disagreement between the calculated and measured data. These disagreements between the calculated and measured data show the uncertainties of the two-and multi-temperature models and also show that the thermochemical nonequilibrium behind a strong shock wave is not understood well at the intermediate and higher hypersonic speeds.…”

“…In these calculations, the upstream pressure is 1.0 Torr, the temperature is 300 K, and the shock velocity is 6.2 km/sec. In this case, the total enthalpy of the freestream is about 20 MJ/kg and the density is 1.497 × 10 −6 g/cm 3 . In figure (a), the rotational temperature relaxation time of the 4-T and Parker model is so fast that the mode is almost in equilibrium, and there exists discernable differences between the calculated temperatures and measured data.…”

Implementation of a Blowing Boundary Condition in the LAURA Code

“…However, some efforts at performing a coupled analysis have been reported (Refs. [1][2][3] where computational solutions of the flowfield and the ablating material were performed in an iterative fashion. While much success has been achieved using an uncoupled analysis for design, it is of interest to obtain higher fidelity (coupled) analyses in order to better assess the system and quantify design margins.…”

Reentry Motion and Aerodynamics of the MUSES-C Sample Return Capsule

“…To assess the aerodynamic heating, the convective and radiative heating at the stagnation point were modeled as a function of air density and flight velocity, whose parameters were evaluated by a series of aerothermodynamic analyses taking into account the radiant in the high-temperature shock layer and succeeding flow, and interaction between outer flow and ablation products. [9][10][11][12] From the results of ground heating tests of the thermal protection materials, 11,12) the acceptable maximum heat flux is 15.5 MW/m 2 and the acceptable total heat input is less than 360 MJ/m 2 . Table 2 summarizes the maximum heat flux and total heat input of several reentry trajectories where the flight path angles are changed parametrically from À10 through À14 .…”

“…On the other hand, the convective and radiative heating at the stagnation point was also modeled as a function of air density and flight velocity, whose parameters were evaluated by a series of aerothermodynamic analyses taking into account the radiant in the high temperature shock layer and succeeding flow and interaction between outer flow and ablation products. [9][10][11][12] The results of balloon-drop tests enabled data modification in the transonic region and also revealed that the angle of attack must be less than 15 at parachute deployment and less than 5. 5 at maximum dynamic pressure.…”