关键词: 微型阀, CFD, 流固耦合, 瞬态流场特性, 灵敏度分析

Abstract: Aviation miniature plug-in relief valve in aircraft hydraulic systems has micro channel structure. The mechanism of inducing transport characteristics of internal fluid as well as the mechanism inducing two-phase flow remain un-clear. The influence of characteristic parameters on product features is not yet well-defined. Therefore, it is an ur-gent need to develop relevant simulation models for analysis and perform experimental test. This research，taking an aviation plug-in relief valve in aircraft hydraulic systems as the object，conducts simulation and experimental studies. In the simulation calculation, the influence of the global structural changes and the migration of partial boundary conditions of valve caused by the spool motion process were considered. Based on the fluid-structure coupling technology, a CFD computational domain division coupling technology was proposed specifically for the complex flow passage structure of the relief valve researched in this paper, which was used to establish a numeri-cal calculation model for global domain of valve. Based on full cavitation model, turbulence model and spool dy-namics calculation model, this computational model can accurately simulate transient characteristics throughout the entire operating cycle, providing insights into the dynamic evolution law of distribution of pressure field, velocity field, cavitation characteristic, and the dynamic variation of spool kinetic characteristics with spool action. To ensure the accuracy of the simulation, performance test device is built. On this basis, a surrogate model for the input output mapping relationship of the valve CFD model was constructed which greatly improves the computational efficiency of the original model. It is applied to large sample model evaluation, and the global sensitivity analysis of the open-ing and closing and flow characteristic parameters to the input parameters is carried out. Results show that the opening and closing process of the researched valve are continuous, rapid, and stable which can effectively ensure system security. The pressure-flow rate results obtained from simulation are in good agreement with the experi-mental data, and the maximum error throughout the entire cycle remains within 5%. Furthermore, the spring char-acteristics and maximum displacement has a significant impact on the valve’s opening and closing characteristics, requiring particular attention on the design and manufacturing processes of this component. The studies contribute to a deeper understanding of the intricate flow mechanisms within the miniature plug-in relief valve. It also can pro-vide theoretical guidance for the development process and holds significant value in enhancing the operational reliability and stability of the hydraulic control system in which it is employed.

Key words: Micro valve, CFD simulation, Flow-structure coupling, Transient flow field characteristics, Sensitivity analysis