09 N Ö Entropy Layers

The entropy layer on a blunt-nosed cone is analyzed, in view of the difficulties it produces in numerical computations. A rule is given to determine at what distance from the nose the entropy layer is a given fraction of the shock layer, for a given free stream Mach number. A simple and very efficient way of computing flows with strong entropy layer effects is given. It consists of inserting two streamlines representing loci of rapid changes in entropy derivatives, and forbidding differentiation across such lines. This research was conducted in part under the sponsorship of the Office of Naval Research under Contract No. N00014-67-A-0438-0009, Project No. NR 061-135, and in part by the Advanced Research Projects Agency, monitored by the U.S. Army Research Office-Durham under Contract No. DAHCO4-69-C-0077. Professor, Dept. of Aerospace Engineering and Applied Mechanics. * Postdoctoral Fellow, Dept. of Aerospace Engineering and Applied Mechanics; on leave of absence from the Politecnico di Torino, Italy.