Development of the active gas generator for high altitude firing test benches

The results of research on increasing the efficiency of a firing test facility for testing thrusters under high-altitude conditions are presented. The increase in efficiency consists in reducing the expansion pressure generated by the ejector and the flow of the active gas (air) consumed by it. Experimental studies were carried out using three versions of gas generators developed by the author which ensure an increase in the energy of the active gas before it is supplied to the ejector. When using the GG-1 gas generator with working media such as air, kerosene and water, the vacuum of less than 1 mm Hg was achieved with the air mass flow rate of 1.1 kg/s (the ejector provides a vacuum of 13 mm Hg with the cool air flow rate of 2 kg/s). However, the design features of the gas generator led to a cumbersome system of supplying working fluids and a complicated start-up sequence. The GG-2 gas generator with air and kerosene as working media failed to provide the temperature of the active gas below 600°C, therefore, to prevent ejector malfunctioning, GG-2 was turned off when the rarefaction reached 13 mm Hg. The air mass flow rate was 1.1 kg/s. The working media of the GG-3 gas generator are air and kerosene or air and natural gas. The design of the GG-3 makes it possible to regulate the temperature of the produced active gas. When working on kerosene, a vacuum of 4 mmHg was reached with the air mass flow rate of 1.5 kg/s. The studies of GG-3 using natural gas as a fuel are going on.