Research on the Correlation Between Structural Deformation and Flow Field Characteristics of Ejector Baffle Based on Fluid–Structure Coupling Analysis

Abstract Natural gas extraction using the ejector to solve the problem of transport difficulties caused by the reduction of wellhead pressure, by adding a baffle structure at the outlet of the ejector nozzle can improve its performance, while the baffle length, shape, and wall thickness variations will affect the ejector's performance. The bidirectional fluid–structure coupling method is used to analyze the deformation of the ejector shell, then analyze the vortex nucleus and the turbulent kinetic energy distribution to research the internal flow change mechanism. The results show that the deformation of the ejector shell is mainly concentrated in the mixing chamber, the deformation of the nozzle and the baffle decreases with the increase of the outlet pressure, increases first with the rise of the baffle length and then decreases, which confirms that there exists an optimal range of the length, and the deformation is large in the case of a large variation of the baffle thickness. In addition, vortex structures with different velocities exist from the nozzle throat to the inlet of the diffusion chamber, and the vortex distribution has a certain relationship with the shape and the length of the baffle. Meanwhile, the distribution of flow vorticity and turbulence kinetic energy enables to analyze more intuitively the reasons for the performance enhancement of the baffle when it is added as well as the relationship between the variation of the baffle length or shape and the flow of the fluid.