A simplified means of providing first estimates to laminar heating rates on isothermal axisymmetric blunt bodies
An approximate scheme for the rapid calculation of first estimates to the laminar heat transfer distribution over isothermal axisymmetric blunt bodies is developed. The method devised is free of any integral relations and reduces the required computing effort to a simple slide rule task. The simplicity of the method is due to the introduction of a new heat transfer parameter which is shown, from a semiempirical study, to undergo only moderate variation in regions where the heat transfer experiences order of magnitude changes. Based on these results, a series expansion for the parameter of interest is obtained through the fourth order term. Even though the perfect gas laws are employed in the series expansion, the resulting effect on the heat transfer ratio is felt to·be small.
To substantiate the method, the heat transfer computed by the present scheme was compared with experimental, first-order exact, and Lees' approximate scheme for six body shapes of general interest. In all cases, fair to moderately good results were obtained. It is felt that any loss in accuracy is readily compensated for by the fact that the present method requires no numerical integration and therefore is extremely easy to apply.