Ablation-Products Radiation from Cones
Conical bodies with ablation heat shields have been proposed to reduce the total heating of vehicles entering planetary atmospheres at hyperbolic speeds. The radiant emission from the products of ablation constitutes a source of heat input into the body. This source of heating has previously been studied for blunt bodies (NASA TN D-1978), and ballistic-range data have been correlated by means of a boundary-layer analysis. In the present study, the correlation parameters derived from the blunt-body tests are combined with solutions of the boundary-layer equations for laminar flow with mass injection for cones. Predictions were thus made of the ablation-products radiation to be expected on cones. Tests of polyethylene and polycarbonate 30° half-angle cones have been conducted to test the predictions. It is found that the ablation-products radiation of the cone models is predicted within a factor of 2. It appears that the present approach may be used for other shapes.