Numerical simulation of fluid-solid coupling of blades in the last stage of a steam turbine

From the standpoint of coupling of non-steady flow with elastic blade vibration, studied was the forced response of blades, which is of major significance for the high-cycle fatigue of blades. By using commercial programs CFX and ANSYS, a fluid-solid coupling calculation was performed of the last stage of a steam turbine at its design status with a passage-inside flow chart and blade vibration stress at a given damping level being obtained. A contrast analysis of the flow field unsteady calculation results with those under uncoupled conditions was conducted. It has been found that the coupled vibration and deformation exercise a relatively small influence on the time-averaged load of blades, but there exists a remarkable influence on the unsteady mutual reaction between the stator and rotor.