An Investigation of Nucleating Flows of Steam in a Cascade of Turbine Blading-Theoretical Treatment

Abstract

This paper describes the theoretical part of an investigation into nucleating flows of steam in a cascade turbine nozzle blading. The main flow field is regarded as inviscid and treated by the time-marching technique. The viscous effects are assumed to be concentrated in boundary layers which are treated by the integral method. The agreement obtained with the observed surface pressure distributions and overall efficiency measurements is very good.

A pressure based Eulerian–Eulerian multi-phase model for non-equilibrium condensation in transonic steam flow

“…Partial evaporation of the moisture is also observed through the oblique shock at the suction side of the trailing edge where the wetness fraction reduces from 5% to %4%. These flow features are consistent with that obtained by previous studies using different modelling approaches [5,8,9]. …”

“…However, since the real flow behavior in turbines is considerably more complex more advanced methods for two-dimensional calculations were developed [4,5]. These methods were based on inviscid time marching schemes with a Lagrangian tracking module included to track the particle motion explicitly.…”

Governing Equations

“…Another practical example of real gas is the simulation of steam or, which is more demanding, of wet steam in turbomachinery applications [29][30][31][32][33][34][35][36][37][38][39]. In the later case, where the steam is mixed with water droplets, so that we speak of multiphase flow, it is either possible to solve an additional set of transport equations, or to trace the water droplets along a number of streamlines.…”

Numerical simulation of a new hollow stationary dehumidity blade in last stage of steam turbine

“…The most effective existing measure to prevent or mitigate the water erosion is slotting suction ports in suitable locations of the hollow stationary blades' pressure surface or suction surface, by making use of static pressure between the inner and outer slots to remove the water film or stream on the surface [4][5][6]. In order to improve the efficiency of this method, many researches were conducted to study the effect of geometric parameters (as position, width, pressure, the angle between suction slot and the blade's surface, etc) on the dehumidity efficiency [7][8][9][10][11].…”