TY - JOUR
TI - Investigation on the unsteady pressure fluctuation characteristic in the blade tip seal of steam turbine based on spectrum
AU - Li Pan
AU - Cao Lihua
AU - Si Heyong
AU - Wang Wenlong
JN - Thermal Science
PY - 2020
VL - 24
IS - 6
SP - 3823
EP - 3834
PT - Article
AB - The paper presents the unsteady numerical simulation results of tip leakage flow in high pressure steam turbines, and also presents the influence analysis of leakage vortexes on pressure fluctuation characteristics of rotor cascade under different blade tip seal clearances. The numerical method for calculating is based on the large eddy simulation turbulence model and the pressure fluctuation of rotor cascade which induced by the unstable leakage vortexes is obtained by frequency spectrum analysis. The results show that the vortex frequencies in tip seal cavity contain both the wheel rotating frequency and the high frequency caused by the tip leakage flow breaking into small scale vortexes. The unsteady characteristics of tip leakage flow also induce steam exciting force which changes with the time.