Mach 4 Wind Tunnel Experiment of Hypersonic Pre-Cooled Turbojet Engine

Abstract

Pre-cooled turbojet engine is investigated to realize Mach 5 class hypersonic transport aircraft. The engine has been demonstrated under sea level static and Mach 2 flight conditions using hydrogen as fuel. Presently, Mach 5 propulsion wind tunnel test using liquid hydrogen is planned and the engine components such as pre-cooler, core engine, afterburner and exhaust nozzle are under development. The engine components were tested under Mach 4 simulating condition by connecting the pre-cooler inlet to an air supply facility. The engine was tested in a propulsion wind tunnel with Mach 4 flight condition. Liquid nitrogen was supplied to the pre-cooler as a coolant in place of liquid hydrogen. Gaseous hydrogen was supplied to the main burner to drive the turbine with the combustion gas. As a result, high temperature structure and cooling system was proved to endure Mach 4 high temperature airstream. Wind-mill starting sequence of the core engine under Mach 4 flight condition was confirmed. Gross thrust of the core engine was obtained as an initial evaluation of elemental performance. Nomenclature GH2= gaseous hydrogen GN2 = gaseous nitrogen LH2 = liquid hydrogen LN2 = liquid nitrogen TIO = Intake outlet (pre-cooler inlet) air temperature TFDI = flow duct inlet (pre-cooler outlet) air temperature TPCIN = pre-cooler inlet coolant temperature TPCOUT = pre-cooler outlet coolant temperature TEIN = evaporator inlet fuel temperature TEOUT = evaporator outlet fuel temperature PTIO = intake outlet air total pressure POUT = compressor outlet air total pressure

Starting Characteristics of Hypersonic Pre-cooled Turbojet Inlet

“…Pressure loss performance and heat exchange performance of the precooler are acquired by the engine direct connect firing tests 8 . Figure 11 shows the picture of the engine direct connect firing test (PCTJ5).…”