Constraint-Aware Multi-Parametric Mass Optimization and Volume Assessment of an Electric-Pump Feed System for Liquid Rocket Engines

This article presents a constraint-aware multiparameter methodology for mass optimization and volume assessment of an electric-pump feed system (EPFS) for a liquid-propellant rocket engine. Preliminary EPFS sizing must account for coupled battery energy and peak-power limits, electrical-distribution mass, and thermal feasibility across operating conditions. The proposed framework combines component-based mass estimation with DC-bus-dependent distribution sizing, motor–inverter thermal screening, and preliminary core hardware-envelope volume assessment across prescribed thrust and burn-duration scenarios. Particular attention is paid to the combined consideration of the energy and power limitations of the battery pack, which allows for determining the transition between power-limited and energy-limited modes. Additionally, the model treats battery peak-power capability and motor–inverter thermal admissibility as feasibility constraints, while the total EPFS mass is used as the primary launch-oriented objective. The results demonstrate that the governing EPFS limitation changes with operating duration, transitioning from peak-power-controlled battery sizing to energy-controlled sizing and ultimately to the subsystem mass constraint. For a 25 kN, 120 s scenario, the minimum-mass configuration identified within the evaluated design set yielded model-predicted reductions of 47.4% in EPFS mass and 47.1% in estimated core hardware-envelope volume relative to the adopted baseline. The methodology provides a quantitative basis for preliminary EPFS configuration screening, mass minimization, and core-hardware packaging assessment, subject to design-point efficiency assumptions and simplified thermal and volumetric models.