Abstract: Aiming at the structural strength of the valve adjusting structure of the marine gas turbine ejector under fluid-solid-thermal coupling， the three-dimensional flow field of the ejector and the structural model of the valve plate were established. The steady-state and transient simulation analysis of the flow field were carried out by using the computational fluid dynamics (CFD) method. Taking the transient simulation results as the boundary conditions of the finite element model， the sequential unidirectional fluid-solid-thermal coupling analysis including thermal， aerodynamic and centrifugal loads was carried out. The result showed that compared with the steady-state simulation， the trend of transient simulation results is similar， but the pressure difference is larger. The steady-state solution of the time-varying load may lead to underestimation of strength. For the valve adjusting structure， the thermal load plays a major role in the deformation and stress of the valve plate. The bending stress caused by the aerodynamic load can offset part of the bending stress caused by the thermal load， while the centrifugal load has little effect on the structure， which can be ignored. The analysis method can be used for the structural design and optimization of such typical motion adjusting structures as ejector valve adjusting structure.

Key words: motion adjusting structure; multi-field coupling; time-varying load; computational fluid dynamics (CFD); dynamic characteristics