High speed rotorcraft propulsion system studies

bofan and counterrotation propfan as leading convertible engine candidates. An advanced technology 8wo shp class turboshaft engine has been configured for high dpeed rotorcraft a p plications. The engine features a twoioncentric-shaft core with a front drive power turbine. Recent high speed rotorcraft airframe studies have identified a desired turboshaft engine constant powerhariable output speed o p erating characteristic. This paper presents the study results of incorporating variable geometry turbines in the engine to accomplish this power/speed characteristic,