Theoretical and experimental studies of gas preparation system for pressurization and reactive control system of launch vehicle

A new gas preparation system (GasPS-RCS) is proposed to solve two tasks: (A) to heat helium gas for tank pressurization; (B) to prepare gas for the Launch Vehicle (LV) Reactive Control System (RCS) at the LV orientation and stabilization sections of the LV on passive parts of the flight trajectory, to provide conditions for launching the Liquid Rocket Engine (LRE). The system includes a gas generator based on hydrogen peroxide, a separator for water separation, heat exchangers independent of the LRE, and gas-jet nozzles. The proposed new system allowed to reduce the length of pressurizing gas lines and reduce the increased helium gas consumption during the heat exchanger warm-up interval of the LRE during its launch. A special advantage of the proposed system is the possibility of ground testing of heat exchangers without an operating LRE. A mathematical model based on the first law of thermodynamics was used to perform a comparative analysis of GasPS-RCS with traditional pressurization and RCS systems. To validate the mathematical model, the experimental studies of helium pressurizing of a liquid nitrogen tank were conducted. The results show that the deviation of experimental and calculated values for pressure is 1.1% and for temperature up to 2%. According to the results of comparative analysis, the GasPS-RCS is 259 kg lighter for the first stage and 80 kg lighter for the second stage of the LV.