Study On Flow-induced Vibration Of Tube Using Finite Element Method

Tube system is involved in all areas of production, its dynamic problems may directly affect the safety of the entire engineering system, therefore it has important research significance and value and it is necessary to analyze and study the flow-induced vibration of the tube deeply. Based on finite element analysis software ANSYS Workbench and CFX, the flow-induced vibration phenomena of tube in engineering were studied in this paper. By using the Bi-directional fluid-solid coupling method,the single-tube and three-tube finite element analysis models under the transverse flow in high Reynolds number environment were established respectively. The response of the system at different flow rates was calculated and the corresponding results were analyzed.Firstly, based on the engineering example, the analysis method and the instability mechanism of the stability of the tube system under the transverse flow were summarized. Bi-directional fluid-solid coupling technology and several commonly used turbulence models were introduced. The single tube under the transverse flow was taken as an example; the applicability and accuracy of the different turbulence models were analyzed. Finally, the LES large eddy model was chosen as the turbulence model. Also, the size of the flow field was selected; the division of the grid and the setting of the calculation time step were discussed.Based on the parameters discussed above, by changing the flow velocity, the single tube model was numerically calculated. It was found that when the flow velocity exceeds the critical velocity,the trajectory of the tube is "8",and the flow field is also periodic. Furthermore,it was found that the amplitude of the structural response is largest when the frequency is close to the natural frequency of the structure, that is,the so-called "lock frequency" phenomenon.Finally, the stability of the ballistic stability of the parallel three tubes was analyzed. The influence of the tube spacing and material properties of the system was discussed and in some tube spacing and material characteristics of the case, the movement trajectory would not be "8" font oscillation.