Investigation on the flow rate matching mechanism and energy losses in a two-stage double-ended fuel supply pump system

The two-stage double-ended fuel supply pump system (TDPS) features a design with multiple inlets and outlets. It can operate in series-parallel mode through various combinations to achieve fuel pressurization and matching. This adaptability enables its widespread adoption in the aviation sector. This paper employs numerical simulations and experimental verification to clarify the flow rate matching characteristics in series-parallel operation and their impact of leakage losses within the pump system. The research indicates that the difference in the performance curves of the first-stage pumps is a significant factor contributing to the uneven flow rate matching during parallel operation. The flow difference between the two first-stage pumps increases first and then decreases with the increase of flow rate, reaching the maximum at 0.6Qd, which is 0.15Qd. When the flow rate is close to the rated value, the difference gradually decreases. In the series operation mode, the pressure difference of the non-supplied side pump leads to leakage, which aggravates the fluid disorder in the pump. However, the presence of radial impeller increases the resistance of internal leakage and reduces the leakage. Entropy production analysis further confirms that the main sources of energy losses in the system are wall dissipation and turbulent dissipation. The leakage will increase the energy dissipation in the pump and the pump located downstream of the confluence section has the highest entropy production losses. The study reveals the mechanism of internal flow and energy losses in the TDPS. The findings establish a theoretical foundation for optimizing both the design and operational efficiency of similar systems.