境界層を伴う先細ノズル流れのチョークに関する理論解析

抄録

To understand choking phenomena of real nozzle flows, an analysis of weak shock waves in duct flows with boundary layers has been carried out by the control volume method where an appropriate mean flow is assumed over a given cross section of the flows. Relations for plane sound waves as the limiting case of the weak shock waves are presented. The criteria for choking and discharge coefficients of convergent nozzles taking account of boundary layers are shown and discussed. As a result, it is found that the ratio of the boundary layer thickness to the duct half-height (or radius in axisymmetric geometries) at the nozzle exit of a convergent nozzle significantly affects choking conditions as well as discharge coefficients.