Thermal Performance Characteristics of an 80-Ton Variable-Thrust Liquid Engine for Reusable Launch Rockets

Abstract

In this paper, an 80-ton thrust liquid rocket engine (hereinafter referred to as an LRE) with a gas generator cycle, a 5:1 thrust throttling ratio, and an integrated flow regulator/gas generator (hereinafter referred to as an IFRGG) is analyzed. This LRE can be used during the first stage of launching, second-stage and upper-stage space missions, and moon/mars low-orbit hovering and soft landing, and it can also be used with various near-space multipurpose flight vehicles. The thermal performance model of the variable-thrust LRE is established, the influence of the main LRE design parameters on the performance optimization is analyzed, and an optimal selection of the design parameters under certain constraints is completed. A performance evaluation was successfully conducted, and we determined the main structural parameters at the sea-level design point; additionally, we evaluated the LRE performance, matched the system parameters under a 100–20% variable-thrust operation, and conducted an analysis on the LRE operating characteristics under a wide range of variable-thrust operations. The LOX/kerosene propellants were selected, and the vacuum-specific impulse of the LRE decreased from 303.2 s to 289.2 s; this followed an approximate linear law, with a decrease of about 4.62% when the thrust was varied in the wide range of 100–20%. The variable-thrust LRE still had a better vacuum performance under a very deep throttling condition. The reason why the specific impulse was low under the deep throttling condition is that it was greatly affected by the different atmospheric pressure that was caused by the varying flight height and the insufficient atomization and combustion of the propellant; however, because of its wide range of variable-thrust working abilities, it is suitable for various special flight missions.

Effects of Local Mixing Ratios and Mass Flow Rates on Combustion Performance of the Fuel-Rich LOX (Liquid Oxygen)/kerosene Gas Generator in the ATR (Air Turbo Rocket) Engine

“…The stages of liquid droplet breakup, evaporation, and mixing with oxidants in heated flow were planned to be added at later stages of the study. Yao and Zhou et al [23] established the thermal performance model of the variable-thrust liquid rocket engine and analyzed the influence of the main liquid rocket engine design parameters on the performance optimization, matched the LOX/kerosene propellants system parameters under a 100-20% variable-thrust operation, and conducted an analysis on the liquid rocket engine operating characteristics under a wide range of variable-thrust operations. Han J et al [24] conducted their experiments to investigate the propagation characteristics of the rotating detonation wave with fuel-rich gas generator, and the effects of the basic parameters on the rotating detonation KFRG.…”