 central jet base pressur cylindr afterbodi superson stream central jet base pressur cylindr afterbodi superson stream report describ experiment investig factor base flow jet structur cylindr after-bodi central nozzl interchang nozzl test converg-diverg design mach number 2 0 jet base diamet ratio rang 0 2 0 8 nozzl diverg angl rang converg jet base diamet ratio 0 6 main experiment programm free-stream mach number 2 0 boundari layer turbul after-bodi nozzl measur base pressur surfac pressur distribut insid nozzl thrust nozzl mass flow rang jet pressur programm supplement compar test jet exhaust air static test read intern nozzl pressur jet thrust jet pressur schlieren photographi extens test extern flow present form curv show separ effect jet pressur ratio jet base diamet ratio nozzl design mach number nozzl diverg angl base pressur thrust special case base bleed discuss separ curv includ static test jet pressur ratio nozzl geometri jet thrust gener method correl data annular base pressur propos discuss essenti method compar pressur annular base calcul pressur correspond two-dimension base correl reason well success appli extens data 