Choice of gas temperature at the turbopump turbine inlet

The article considers some issues of choosing the gas temperature at the inlet of a liquid rocket engine turbopump turbine. The turbine is one of the key elements of the engine and its operability depends on the gas temperature. In addition, the turbine inlet gas temperature determines its power and main parameters of the engine – chamber pressure and thrust. The higher turbine inlet gas temperature, the higher the chamber pressure and the better engine performance. The permissible temperature of the turbine structure is determined by the required safety margins and durability of the turbine rotor blades. For expendable engines, the safety margin is determined by the material short-term strength at maximum gas temperature. For reusable engines with a long service life, the safety factor is determined by the material long-term strength. The article presents the main factors affecting the choice of the generator gas temperature. It shows that one of the main factors is the non-uniformity of the temperature field at the turbine inlet. The choice of maximum admissible temperature is determined not so much by the engine schematic – with the afterburning of oxidizing or reducing generator gas, but by the strength and durability of the structure with account of the influence of temperature factors.