Analysis of Fluid-Solid coupling heat transfer characteristics of hydrogen circulating pump

The hydrogen circulating pump (HCP) is in a high-temperature state during operation due to the heat generated by the pressure change of the transported gas. The current research on the flow characteristics of the HCP has not taken into account the influence of internal heat transfer factors, resulting in significant errors between the research results and actual test results. In this article, we define the contact modes of the fluid-solid interfaces based on heat transfer theory, propose a step-by-step calculation method based on different time scales, and complete the simulation of the fluid-solid coupling model. Compared with the test flow rate of 15.44 g/s, the fluid-solid coupling model considering heat transfer factors calculated a flow rate of 15.15 g/s with an error of only 1.85 %, while the single fluid model without considering heat transfer effects calculated a value of 14.67 g/s with an error of 5.0 %. Analyzing the internal mechanism of heat transfer leading to an increase in simulated flow rate, the external surface heat dissipation and internal heat conduction on one hand lead to a decrease in gap leakage flow rate, thereby reducing leakage volume, and on the other hand, increase the density of gas transported in the rotor cavity area, thereby improving the conveying capacity. The calculation method proposed in this article solves the problem of the large time difference between instantaneous fluid flow and slow heat transfer, shortens the calculation time, has higher calculation accuracy, and plays an important role in the precise design process of HCPs.