双 S 弯喷管的流固耦合特性研究

In order to clarify the fluid-structure interaction characteristics of serpentine nozzle，the structural deformation features as well as internal flow and external jet characteristics of double serpentine convergent nozzle under the action of fluid-structure interaction had been numerically simulated. Results are obtained as follows：The non-uniform flow fields are produced by round inlet transiting rectangular outlet curved configuration of serpentine nozzle，which strengthens the elasticity of its own structure at the same time. Then，the coupling mechanisms of serpentine nozzle are formed by the transferring aerodynamic force and deformable displacement data between flow field and structure. The maximum value of deformable displacement of serpentine nozzle exerted by aerodynamic loads is 25.3mm along Y direction，which is located at the center of the upper wall of the nozzle outlet section. When the structural deformation is stable，the airflow on the lower wall of the second inflection accelerates to local supersonic where the wall static pressure is greatly reduced，the flow separation region is presented around the upper wall downstream of the first inflection，and the plume core region near nozzle exit deflects upward along the axial direction.The discharge coefficient and thrust coefficient decrease by 0.6% and 1.8% respectively under the action of fluid-structure interaction.