Combined cycle integrated combustor and nozzle system
View Patent ↗An engine that operates and produces the entire required vehicle thrust below Mach 4 is useful for a Hypersonic combined cycle vehicle by saving vehicle and engine development costs. One such engine is a combined cycle engine having both a booster and a dual mode ramjet (DMRJ). The booster and the DMRJ are integrated to provide effective thrust from Mach 0 to in excess of Mach 4. As the booster accelerates the vehicle from Mach 0 to in excess of Mach 4, from Mach 0 to about Mach 2 incoming air delivered to the DMRJ is accelerated by primary ejector thrusters that may receive oxidizer from either on-board oxidizer tanks or from turbine compressor discharge air. As the TBCC further accelerates the vehicle from about Mach 0 to in excess of Mach 4 exhaust from the turbine and exhaust from the DMRJ are combined in a common nozzle disposed downstream of a combustor portion of the DMRJ functioning as an aerodynamic choke.
1. A method of operating a combined cycle engine, comprising the steps of:
operating a booster to produce a booster exhaust plume;
operating a dual mode ramjet (DMRJ) to produce an amount of DMRJ flow; and
creating using said booster exhaust plume an aerodynamic throat downstream of a low area ratio (AR) DMRJ combustor exit within a DMRJ nozzle.
2. The method of claim 1 wherein said booster exhaust plume is underexpanded.
3. The method of claim 1 wherein said booster is a rocket engine.
4. The method of claim 1 wherein said booster is a low speed accelerator.