Numerical simulation of fluid-structure interaction for axial flow blade based on weak coupling

Abstract

Numerical simulation of three-dimensional flow in whole flow passage of axial flow hydraulic turbine was conducted based on the Reynolds-averaged N-S equations and the standard k-ε model. Stress analysis of axial flow blade were carried on by elasticity unsteady FEM. The fluid domain and solid domain were calculated by sequential iteration. Based on weak coupling technology, the fluid-structure interaction analysis of the axial flow blade was conducted. Instantaneous flow field characteristic and stress distribution on blade were analyzed. According to the comparing with the results of pure flow numerical simulation, the pressure difference between press side and suction side increases after considering the FSI, to a certain extent, which will worsen cavitations performance of the blade. Meanwhile, stress distribution on the blades do not change significantly, but the maximum stress value increases markedly, and the maximum displacement reduces slightly. The research demonstrates that the FSI not only changes the distribution of the flow field in blade area, but also have a greater impact on the stress of the blades. © Published under licence by IOP Publishing Ltd.