Components Design of an Experimental System for a Lab-Scaled Electric Pump-Fed Cycle

An electric pump-fed cycle pressurizes the propellant using a pump, in a manner similar to how a gas generator cycle works. Because a pump is electrically driven by a motor, an electric pump-fed cycle has a relatively small number of components and a simple system compared to a gas generator cycle. Therefore, an electric pump-fed cycle has advantages in that the development costs and required skill levels are lower than those associated with a gas generator cycle. In addition, due to the improved technology of electric motors and batteries, it is considered that an electric pump-fed cycle can be efficiently operated in a commercial space launch vehicle. With regard to the battery technology prospects, the energy density of a battery will be improved by four times by 2050, which will increase the payload capacity of a launch vehicle with an electric pump-fed cycle. Therefore, studies of electric pump-fed cycles are underway in many countries. Most of the studies involve a theoretical performance analysis for a comparison with other feed systems or are limited to design studies of specific components of the electric pump-fed cycle. In order to develop integrated feed system technology for an electric pump-fed cycle, experimental work is done using test equipment. In this study, the 30 kN class engine of an electric pump-fed cycle with LOx/LCH₄ is scaled down to 500 N using lab-scale test equipment. A Run tank, feed line, motor pump assembly, and valves were designed as components of the electric pump-fed cycle. The initial pressurization and flow control method were also analyzed and designed. The oxidizer and fuel volume flow rates are determined to 5.79 and 4.53 lpm, respectively. In each pump, the pressurization performance requires pressure that exceeds 2.5 MPa. In addition, flow rate control by the opening of a valve can be controlled more broadly than the RPM controlling approximately 4.7%.