TWO-STAGE HEATER FOR A MACH 0 TO 8 FREE-JET ENGINE TEST FACILITY

A two-stage heater system has been installed in Leg IV at GASL to extend the aeropropulsion free-jet engine testing capability of the test leg to Mach 8. The test leg, which uses a pebble bed storage heater as the first stage to preheat the air, had previously been limited to approximately Mach 5.3 simulation. The newly-designed second stage burns hydrogen and oxygen to boost the operating temperature of the facility from 2500 R (1400 K) to 4500 R (2500 K) to achieve the Mach 8 capability. This stage, referred to as the booster heater, connects directly to the outlet of the pebble bed vessel. The combustion process employs hydrogen combustion with oxygen replenishment to