Dynamic modeling and experimental study of a complex fluid-conveying pipeline system with series and parallel structures

Abstract

In this paper, the transfer matrix method is improved and the dynamic model of a complex fluid-conveying pipeline system with series and parallel structures based on the improved transfer matrix method (ITMM) is developed. Firstly, the structural coupling between parallel pipelines is realized by deducing the deformation coordination equation and expanding the matrix dimension. Then the time domain information is converted into frequency domain information by Laplace transforms. Finally, an efficient ITMM is derived according to the field transfer relationship. Compared with the traditional transfer matrix method, the ITMM can consider both fluid-structure interaction and structural coupling between two parallel liquid-filled pipes in a complex fluid-conveying pipeline system. And the model constructed in this paper is closer to the real aero-engine pipeline system. In addition, two auxiliary verification models (FEM-Beam, and FEM-Solid) are established. Furthermore, a self-designed pipeline system modal test rig is built, and the effectiveness of the dynamic model is verified by comparing the modal results of simulation and experiment. Finally, the effects of different excitation and damping on the dynamic characteristics of the complex fluid-conveying pipeline system are analyzed. The modeling method proposed in this paper can provide positive guidance for the vibration analysis and modal test of the specific aero-engine pipelines with complex series and parallel structures.