PROPAGATION CHARACTERISTICS OF OSCILLATING PRESSURE IN TURBOMACHINERY PASSAGE

摘要

The propagation characteristics of oscillating pressure in complex turbomachinery passages were determined by solving the three-dimensional, unsteady N-S equations. Unsteady flow equations were transformed into amplitude equations using the oscillating fluid mechanics theory. The resulting partial differential equations were then reduced to ordinary differential equations using the Parametric Polynomial Method (PPM). This fast numerical method was used to determine the propagation characteristics of pressure oscillations in turbomachinery. Two turbomachinary accidents due to excessive oscillating pressures were analyzed and results were presented in this paper. One accident is the rupture of cast-in diaphragms in a steam turbine. The other is the failure of an oxygen pump inducer in a rocket. Both examples demonstrate that the propagation of oscillating pressures is a very important mechanism for the flow-induced vibrations, and needs to be studied systematically.