超临界燃油喷射特性受喷嘴长径比影响的实验研究

In order to obtain the effects of nozzle geometry on supercritical fuel injection characteristics, the performances of the supercritical injection of RP-3 aviation kerosene into a quiescent atmospheric environment were experimentally studied by a microscopic shadowgraphy system. The near-field shock structure, condensation length and jet spreading angle affected by nozzle length-diameter ratio were analyzed in detail. The intercepting shock, Mach disk, and condensation phenomenon downstream of the Mach disk were observed during the injection. With the increasing of the nozzle length-diameter ratio, the condensation length, Mach disk diameter and Mach disk distance were all decreased, and maximum reduction was 15.6%, 56.1% and 30.4% respectively, while the jet spreading angle increased, and its maximum increases up to 12.7%.