Numerical modeling and high-order scheme for wet steam flow

2015 ◽  
Vol 230 (11) ◽  
pp. 1846-1860 ◽  
Author(s):  
Zhirong Lin ◽  
Xin Yuan
Keyword(s):  
Supersonic Nozzle ◽  
Three Dimensional ◽  
High Order ◽  
Process Models ◽  
Steam Flow ◽  
Droplet Growth ◽  
Wet Steam ◽  
High Order Scheme ◽  
Order Scheme ◽  
Wet Steam Flow

A mathematical model of three-dimensional nonequilibrium condensing wet-steam flow is established in Eulerian form, based on conservation laws for a mixture of steam and water droplets. The method of moments is introduced in modeling the droplet spectrum. To describe the nonequilibrium condensing process, models for classical nucleation and enhanced droplet growth are applied. A special high-order implicit scheme is constructed for this condensing flow model. Tables based on IAPWS-IF97 formulae are used in solving the thermal properties of wet steam. The numerical results for a two-dimensional supersonic nozzle and a low-pressure steam turbine stage are compared with experimental data. The good agreement indicates the effectiveness of the condensation model and numerical scheme.

Numerical Solution of Wet Steam Flow through Blade Cascade

2016 ◽  
Vol 821 ◽  
pp. 31-38
Author(s):  
Vladimír Hric ◽  
Jan Halama
Keyword(s):  
Equations Of State ◽  
Suction Side ◽  
Steam Flow ◽  
Droplet Growth ◽  
Wet Steam ◽  
Two Phase ◽  
Blade Cascade ◽  
Flow Through ◽  
Wet Steam Flow ◽  
Non Equilibrium

The paper concerns with the numerical modeling of wet steam flow through a blade cascade in transonic regime with non-equilibrium condensation in 2D. Real thermodynamics of vapor phase is implemented in the way which mostly avoid iterations in order to calculate thermodynamic properties. This equation of state is represented by the function for non-dimensional entropy with independent variables scaled density and scaled internal energy. Other equations of state are used for comparison, namely special gas equation which comes from IAPWS-95 formulation and simple pseudo perfect gas relation. We applied simple homogeneous non-equilibrium approach to model two-phase flow. Laminar compressible Navier-Stokes system of equations is used for the mixture properties. Liquid phase is described by the standard method of moments of droplet number distribution function. We consider obtained numerical results to be in good agreement with the measured data. We note the fact that robust and accurate closure of supplementary liquid system (nucleation rate and droplet growth model) is still not available and most often ad-hoc corrections are proposed by the authors. Results show differences among used equations of state as well. This is apparent mainly in the vicinity of condensation shock region on the suction side.

Modelling and Validation of Wet Steam Flow in a Low Pressure Steam Turbine

2011 ◽  
Author(s):  
Jo¨rg Starzmann ◽  
M. Schatz ◽  
M. V. Casey ◽  
J. F. Mayer ◽  
Frank Sieverding
Keyword(s):  
Steam Turbine ◽  
Droplet Size ◽  
Low Pressure ◽  
Numerical Results ◽  
Steam Flow ◽  
Droplet Growth ◽  
Wet Steam ◽  
Test Rig ◽  
Pressure Steam ◽  
Wet Steam Flow

Results of numerical investigations of the wet steam flow in a three stage low pressure steam turbine test rig are presented. The test rig is a scale model of a modern steam turbine design and provides flow measurements over a range of operating conditions which are used for detailed comparisons with the numerical results. For the numerical analysis a modern CFD code with user defined models for specific wet steam modelling is used. The effect of different theoretical models for nucleation and droplet growth are examined. It is shown that heterogeneous condensation is highly dependent on steam quality and, in this model turbine with high quality steam, a homogeneous theory appears to be the best choice. The homogeneous theory gives good agreement between the test rig traverse measurements and the numerical results. The differences in the droplet size distribution of the three stage turbine are shown for different loads and modelling assumptions. The different droplet growth models can influence the droplet size by a factor of two. An estimate of the influence of unsteady effects is made by means of an unsteady two-dimensional simulation. The unsteady modelling leads to a shift of nucleation into the next blade row. For the investigated three stage turbine the influence due to wake chopping on the condensation process is weak but to confirm this conclusion further investigations are needed in complete three dimensions and on turbines with more stages.

Eulerian-Lagrangian Numerical Simulation of Wet Steam Flow Through Multi-Stage Steam Turbine

2013 ◽  
Author(s):  
Yasuhiro Sasao ◽  
Satoshi Miyake ◽  
Kenji Okazaki ◽  
Satoru Yamamoto ◽  
Hiroharu Ooyama
Keyword(s):  
Steam Turbine ◽  
Turbine Blades ◽  
Steam Flow ◽  
Droplet Growth ◽  
Computational Domain ◽  
Steam Turbines ◽  
Wet Steam ◽  
Multi Stage ◽  
Flow Through ◽  
Wet Steam Flow

In this paper, we present an inclusive tracking algorithm for water droplets in a wet steam flow through a multi-stage steam turbine. This algorism is based on the Eulerian-Lagrangian coupled solver. The solver continuously computes water droplet growth, kinematic non-equilibrium between vapor and droplets, capture and kinetics of droplets on turbine blades, departure of large droplets from the trailing edge of blades, acceleration and atomization of large droplets, and recollisions between blades and droplets. Our Eulerian-Lagrangian coupled solver is used to predict wetness in unsteady three-dimensional (3D) wet steam flows through three-stage stator rotor cascade channels in a low pressure (LP) steam turbine model which is developed by Mitsubishi Heavy Industries (MHI). Droplet groups tracked by the discrete droplet model (DDM) are placed in the computational domain according to the predicted wetness. Interference from the gas phase on the droplets is considered, to track their kinetic and behavior, until they reach the outlet of the computational domain. The aim of this research is to investigate those multi-physics phenomena that trigger all forms of loss in steam turbines. In addition, this method will also be applied to multi-physics problems such as erosion in future work. This paper is presented as a first step in the research. Overviews of model of current coupling solver and several test calculations are presented.

Wet steam flow and condensation loss in turbine blade cascades

2021 ◽  
Vol 189 ◽  
pp. 116748
Author(s):  
Chuang Wen ◽  
Yan Yang ◽  
Hongbing Ding ◽  
Chunqian Sun ◽  
Yuying Yan
Keyword(s):  
Turbine Blade ◽  
Steam Flow ◽  
Wet Steam ◽  
Wet Steam Flow

A fast response miniature probe for wet steam flow field measurements

2016 ◽  
Vol 27 (12) ◽  
pp. 125901
Author(s):  
Ilias Bosdas ◽  
Michel Mansour ◽  
Anestis I Kalfas ◽  
Reza S Abhari
Keyword(s):  
Flow Field ◽  
Field Measurements ◽  
Fast Response ◽  
Steam Flow ◽  
Wet Steam ◽  
Wet Steam Flow

Some Experiments on Wet Steam Flow Visualization in Large Steam Turbine Blading

1976 ◽  
Vol 98 (3) ◽  
pp. 573-577 ◽  
Author(s):  
J. Krzyz˙anowski ◽  
B. Weigle
Keyword(s):  
Steam Turbine ◽  
Steam Flow ◽  
Light Sources ◽  
Phase Flow ◽  
Wet Steam ◽  
Experimental Conditions ◽  
Advantages And Disadvantages ◽  
Primary Droplet ◽  
Last Stage ◽  
Wet Steam Flow

In a series of experiments aimed at the visualization of the wet steam flow in the exhaust part of a 200 MW condensing steam turbine a set of periscopes and light sources was used. The aim of the experiment was: 1 – The investigation of the liquid-phase flow over the last stage stator blading of the turbine mentioned. 2 – The investigation of the gaseous-phase flow through the last stage blading at full and part load. The first part of the program partially failed due to the opaqueness of the wet steam atmosphere for the turbine load higher than 10–20 MW. The detailed experimental conditions will be described. An assessment of the primary droplet size will also be given. The preliminary results of the second part of the program will be outlined. The advantages and disadvantages of the equipment used will be discussed.

HIGH-ORDER SCHEME IMPLEMENTATION USING NEWTON-KRYLOV SOLUTION METHODS

1997 ◽  
Vol 31 (3) ◽  
pp. 295-312 ◽  
Author(s):  
Richard W. Johnson ◽  
Paul R. McHugh ◽  
Dana A. Knoll
Keyword(s):  
High Order ◽  
High Order Scheme ◽  
Solution Methods ◽  
Order Scheme
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