A Comparison of Five Methods of Calculating Aerodynamic Stagnation-Point Heat Transfer at Velocities of 25,000 to 40,000 fps

Abstract

Five methods of calculating aerodynamic stagnation-point heat transfer at velocities of 25,000 to 40,000 fps are considered. Three of these methods are simple extrapolations of techniques previously developed for calculations below 25,000 fps. The other two are methods especially developed for velocities above 25,000 fps. The five methods are: The method of Fay and Riddell [1]; the method of Scala [2]; the reference enthalpy method [3]; the method of Adams [4]; and the method of Cohen [5]. Methods [4] and [5] are the methods developed for the higher velocities. The results are presented in graphical form. It is found that the extrapolation of the reference enthalpy method and the correlation formula of Fay and Riddell yield results so close to those of Cohen that, in view of the uncertainties involved in the latter method, using the former two methods over the range of values considered in the present paper yields results at least as satisfactory as those of Cohen for equilibrium flow. Furthermore it is found that extrapolation of the formula of Fay and Riddell for frozen flow yields results sufficiently close to those obtained by the method of Adams that, in view of the uncertainties of the latter method, the advantage of its use over the former in the range of values under consideration is questionable.