Investigation of Galileo Probe Entry Heating with Coupled Radiation and Ablation
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Aaron J Erb↗
Engineering topics
Aaron J Erb
Publications and source records attributed to Aaron J Erb.
Features of Afterbody Radiative Heating for Jupiter Entry
In this extended abstract, a preliminary analysis of a trajectory-based heating and ablation study in the afterbody of a Jovian entry probe is presented. The radiative flux in the afterbody impinging on the backshell of the probe is investigated with and without the presence of ablation product gas. The heritage tangent-slab approximation for radiative heating is shown to underpredict the radiative heating by as much as 50% in the afterbody making the highfidelity, yet computationally expensive, ray-tracing approach necessary to accurately predict the radiative heating predictions. An investigation into the merits of employing the ray-tracing approach for the prediction of the divergence of radiative flux in the afterbody flow field will be presented in the final manuscript. Nonequilibrium effects in the afterbody region will be investigated in the final manuscript including the impact of electron-ion recombination rates. To bound the problem based on the best available knowledge, an uncertainty analysis will be performed. Sources of uncertainty are identified in the ablation modeling, radiation modeling, flowfield kinetics, and thermodynamic properties of select species.
Thermophysics↗
CFD Validation Study of a Hypersonic Cone-Slice-Flap Configuration
Model validation is the process of determining the degree of accuracy between the real world and the model. The result of model validation can be used to either improve the model through calibration or quantify the model-form uncertainty. This work focuses on estimating the model-form uncertainty through an area metric for a hypersonic cone-slice-flap geometry configuration given the uncertainty in both the simulation and experimental data. A procedure that can give an accurate representation of the model-form uncertainty using a small number of high-fidelity runs is outlined. The work also assesses the impact of using different high-fidelity solvers and different turbulence models. The goal of performing this comparison is to provide a quantifiable measurement of the accuracy of each solver and turbulence model for this type of design. A low-fidelity analysis is also performed to get a model-form uncertainty for this type of analysis. The two high-fidelity CFD solvers used here are VULCAN-CFD and FUN3D, and the low-fidelity results comes from Cart3D.The experimental data comes from the 20-inch Mach 6 Tunnel located at NASA Langley Research Center. The work here shows that the models used tend to under-predict the drag and moment aerodynamic coefficients for this type of design leading to a model-form uncertainty estimate which can account for up to an 86% of the total uncertainty in the model predictions.
Laura M White↗