Structure of high-pressure low-density jets beyond a supersonic nozzle

Free underexpanded jets in a quiescent medium: A review

“…Surprisingly enough, the available data are quite poor and one may only say that it seems to be also dependent on the square root of the pressure ratio [69,70,123]; may sometimes depend on the convergence angle [68,70,117] even if it is not the case for some configurations [56,70].…”

“…16] or [11,Chap. 7] but the moment when this phenomenon occurs is quantitatively poorly known, especially the dependency (and interactions) on the pressure [96,29,62,30,[98][99][100]12,64,123,43,124,84,13,107,90,54]. Nonetheless, among the theoretical studies, the Mach disk location has been supposed to appear at a position such that the conservation equations are satisfied for the section perpendicular to the axis [95].…”

“…Among the available papers, experimental [62,30,12,64,123,124,90], theoretical [96,29,[98][99][100]107] or numerical [132,114,41,115], it is difficult to find quantitative results concerning the passage between regular and singular reflection. However, it seems that the boundary layer behavior and consequently the velocity field and the structure of the first cell are influenced by the shape of the nozzle (especially for CV-DV ones) [62,56,30].…”

“…[ 4-20 1.5, 2 N 2 4 CV-DV nozzles X Ref. [123] 101-73 Á 10 3 1 N 2 , CO 2 CV nozzle X Ref. [83] 1-100 1 N 2 , CO 2 , He 2 CV nozzles X Ref.…”

“…Diameter of the intercepting shock: More studies have been dedicated to this feature, both experimentally [56,[69][70][71]123], theoretically [69,70,72,99,76,139,100,102,140,105,128,107] and numerically [141,137,138,112,117,118,84]. Surprisingly enough, the available data are quite poor and one may only say that it seems to be also dependent on the square root of the pressure ratio [69,70,123]; may sometimes depend on the convergence angle [68,70,117] even if it is not the case for some configurations [56,70].…”