Modeling of radiative heating of base region of Jovian entry probe

The mechanism of radiative heating of the afterbody region of Jovian entry probe is analyzed. A theoretical model is derived to determine the average thermodynamic properties in the expanding region, recirculating region, recompression region, and neck region through application of one-dimensional conservation equations. Flow parameters are obtained from the shadowgraphs of a free-flight test. Radiative transfer is calculated using spectrally detailed computer codes accounting for nonequilibrium. The results show that the most severe heating occurs immediately behind the frustum, and that the recompression and neck regions are the major sources of radiation that heats the base stagnation point. The radiation flux to the base point is slightly stronger with ablation than without, its value being 0.11(43Pb/Ps)squared times that to the front stagnation point, where Pb/Ps is the ratio of base-to-front stagnation point pressures and its value is in the range 0.023-0.066. The time-integrated heat load to the base point is 18(43Pb/Ps)squared kJ/sq cm. Existing experimental data are shown to agree with the theoretical prediction.