Computational Fluid Dynamics Analysis of a Steam Power Plant Low-Pressure Turbine Downward Exhaust Hood

1996 ◽  
Vol 118 (1) ◽  
pp. 214-224 ◽  
Author(s):  
R. H. Tindell ◽  
T. M. Alston ◽  
C. A. Sarro ◽  
G. C. Stegmann ◽  
L. Gray ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Integrated Approach ◽  
Low Pressure ◽  
Operating Conditions ◽  
Exhaust Hood ◽  
Steam Power ◽  
Low Pressure Turbine ◽  
Computational Fluid Dynamics Analysis ◽  
Turbine Exhaust

Computational fluid dynamics (CFD) methods are applied to the analysis of a low-pressure turbine exhaust hood at a typical steam power generating station. A Navier-Stokes solver, capable of modeling all the viscous terms, in a Reynolds-averaged formulation, was used. The work had two major goals. The first was to develop a comprehensive understanding of the complex three-dimensional flow fields that exist in the exhaust hood at representative operating conditions. The second was to evaluate the relative benefits of a flow guide modification to optimize performance at a selected operating condition. Also, the influence of simulated turbine discharge characteristics, relative to uniform hood entrance conditions, was evaluated. The calculations show several interesting and possibly unique results. They support use of an integrated approach to the design of turbine exhaust stage blading and hood geometry for optimum efficiency.

scholarly journals Computational fluid dynamics analysis of the influence of injection nozzle lateral outflow on the performance of Ranque-Hilsch vortex tube

2014 ◽  
Vol 18 (4) ◽  
pp. 1191-1201 ◽  
Author(s):  
Nader Pourmahmoud ◽  
Alireza Izadi ◽  
Amir Hassanzadeh ◽  
Ashkan Jahangiramini
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Vortex Tube ◽  
Operating Conditions ◽  
Energy Separation ◽  
Physical Parameters ◽  
Dynamics Analysis ◽  
Computational Domain ◽  
Computational Fluid Dynamics Analysis

In this article computational fluid dynamics analysis of a three-dimensional compressible and turbulent flow has been carried out through a vortex tube. The standard k-? turbulence model is utilized in order to simulate an axisymmetric computational domain. The numerical simulation has focused on the energy separation and flow field patterns of a somewhat nonconventional vortex tube, which is on the basis of creating an external hole at the end of each nozzle. According to the selected nozzles geometry, some of unfavorable phenomena such as shock wave, high pressure regions and appearing of unsymmetrical rotating flow patterns in the vortex chamber would be recovered significantly. In this way the physical parameters of flow field are derived under different both inlet mass flow rates and outlet pressures of nozzles hole (OPH). The results show that increasing OPH value enhanced the cooling capacity of machine in the most of operating conditions.

scholarly journals CFD Analysis of Shrouded Diffuser Wind Turbine

2019 ◽  
Vol 8 (6S3) ◽  
pp. 2100-2104
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Turbine ◽  
Wind Velocity ◽  
Experimental Testing ◽  
Flow Characteristics ◽  
Operating Conditions ◽  
Computational Fluid Dynamics Analysis ◽  
Cfd Analyses ◽  
Physical Dimensions

The power in the wind is well known to be proportional to the cubic power of the wind velocity approaching a wind turbine. This means that even small amount of its acceleration gives large increase in the power output. Brimmed diffuser shrouds for small wind turbines are being used to accelerate the wind velocity in small wind regimes. The objective of the Paper is to analyze the flow characteristics of brimmed diffuser shroud and to optimize the physical dimensions. CFD analyses are carried out by varying its physical dimensions with the aim of achieving augmented velocity. The effect of flow parameters with the presence of diffuser is analyzed by comparing it with bare wind turbine. The physical dimensions of brimmed diffusers are the parameters considered in this study. The study has been carried with proposed splitted diffuser design. The power yield of the turbine for shifting speeds is gotten and analyzed.The CFD tool CFX would be used to anlayse the flow field around the diffuser. Performance of wind turbine under various operating conditions is generally obtained through an experimental testing and could be cost prohibitive. In this case the computational fluid dynamics analysis provides better results. The capability of using computational fluid dynamics is a test to determine its viability for determining its performance parameters

Computational Fluid Dynamics Analysis of a Hydrokinetic Turbine Based on Oscillating Hydrofoils

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Thomas Kinsey ◽  
Guy Dumas
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Numerical Simulations ◽  
Spatial Configuration ◽  
Operating Conditions ◽  
Power Extraction ◽  
Numerical Predictions ◽  
Hydrokinetic Turbine ◽  
Computational Fluid Dynamics Analysis

The performance of a new concept of hydrokinetic turbine using oscillating hydrofoils to extract energy from water currents (tidal or gravitational) is investigated using URANS numerical simulations. The numerical predictions are compared with experimental data from a 2 kW prototype, composed of two rectangular oscillating hydrofoils of aspect ratio 7 in a tandem spatial configuration. 3D computational fluid dynamics (CFD) predictions are found to compare favorably with experimental data especially for the case of a single-hydrofoil turbine. The validity of approximating the actual arc-circle trajectory of each hydrofoil by an idealized vertical plunging motion is also addressed by numerical simulations. Furthermore, a sensitivity study of the turbine’s performance in relation to fluctuating operating conditions is performed by feeding the simulations with the actual time-varying experimentally recorded conditions. It is found that cycle-averaged values, as the power-extraction efficiency, are little sensitive to perturbations in the foil kinematics and upstream velocity.

Computational Fluid Dynamics Analysis of 3D Hot Metal Flow Characteristics in a Blast Furnace Hearth

2010 ◽  
Vol 2 (1) ◽  
Author(s):  
Chenn Q. Zhou ◽  
D. (Frank) Huang ◽  
Yongfu Zhao ◽  
Pinakin Chaubal
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Blast Furnace ◽  
Metal Flow ◽  
Measurement Data ◽  
Operating Conditions ◽  
Hot Metal ◽  
Furnace Hearth ◽  
Blast Furnace Hearth ◽  
Computational Fluid Dynamics Analysis

The campaign life of an iron blast furnace depends on hearth wear. Distributions of liquid iron flow and refractory temperatures have a significant influence on hearth wear. A 3D comprehensive computational fluid dynamics model has been developed specifically for simulating the blast furnace hearth. It includes both the hot metal flow and the conjugate heat transfer through the refractories. The model has been extensively validated using measurement data from Mittal Steel old, new IH7 blast furnace and U.S. Steel 13 blast furnace. Good agreements between measured and calculated refractory temperature profiles have been achieved. It has been used to analyze the velocity and temperature distributions and wear patterns of different furnaces and operating conditions. The results can be used to predict the inner profile of hearth and to provide guidance for protecting the hearth.

scholarly journals Computational fluid dynamics analysis of a high-throughput viscous heater to process feces and a fecal simulant using temperature and shear rate-dependent viscosity model

2017 ◽  
Vol 8 (1) ◽  
pp. 27-32
Author(s):  
C. L. German ◽  
J. T. Podichetty ◽  
A. Muzhingi ◽  
B. Makununika ◽  
J. Smay ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Shear Rate ◽  
Operating Conditions ◽  
Rate Dependent ◽  
Annular Gap ◽  
Computational Fluid Dynamics Analysis ◽  
Fecal Sludge ◽  
Dependent Viscosity

Abstract Open defecation and poor fecal management facilitates the spread of disease. Viscous heating can pasteurize fecal sludge by creating a high shear field in the annular gap between a stationary, cylindrical outer shell and a rotating inner core. As sludge flows axially through the annular gap, thorough mixing and frictional heating eliminate cool spots where microbes may survive. A viscous heater (VH) compares favorably to a conventional heat exchanger, where cool slugs may occur. Computational fluid dynamics (CFD) was used to determine the effects of geometry and fluid rheology on VH performance over a range of conditions. A shear-rate and temperature-dependent rheological model was developed from experimental data, using a sludge simulant. CFD of an existing VH used the model to improve the original naïve design by including temperature and shear rate-dependent viscosity. CFD results were compared to experimental data at 132 and 200 L/hr to predict design and operating conditions for 1,000 L/hr. Subsequent experimentation with fecal sludge indicated that the CFD approach was valid for design and operation.

Computational Fluid Dynamics Analysis of Gerotor Lubricating Pumps at High-Speed: Geometric Features Influencing the Filling Capability

2016 ◽  
Vol 138 (11) ◽  
Author(s):  
Giorgio Altare ◽  
Massimo Rundo
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
High Speed ◽  
Operating Conditions ◽  
Geometric Features ◽  
Inlet Pipe ◽  
Computational Fluid Dynamics Analysis ◽  
Incomplete Filling ◽  
Computational Fluid Dynamics Cfd ◽  
Circuit Configuration

The paper presents an extensive analysis of the influence on the suction capacity of the main geometric parameters of gerotor lubricating pumps. The study was carried out using a computational fluid dynamics (CFD) model developed with the commercial software PumpLinx®. The model of a reference gerotor unit was validated experimentally in terms of delivered flow rate in different operating conditions, in open and closed circuit configuration. In the former case, different geometries of the inlet pipe were tested. In the latter, the influence of the suction pressure at constant speed was analyzed. After the model validation, several geometric features were changed to assess their influence on the volumetric efficiency in conditions of incomplete filling, such as the thickness and the diameter of the gears, the position of the inlet pipe with respect to the rotors (radial, axial, and tangential), and the shape of the port plate.

Numerical Investigation on the Aerodynamic Performance of a Low-Pressure Steam Turbine Exhaust Hood Using DOE Analysis

2020 ◽  
Author(s):  
Tommaso Diurno ◽  
Tommaso Fondelli ◽  
Leonardo Nettis ◽  
Nicola Maceli ◽  
Lorenzo Arcangeli ◽  
...  
Keyword(s):  
Flow Field ◽  
Steam Turbine ◽  
Low Pressure ◽  
Operating Conditions ◽  
Pressure Recovery ◽  
Exhaust Hood ◽  
Recovery Coefficient ◽  
Pressure Steam ◽  
Pressure Recovery Coefficient ◽  
Turbine Exhaust

Abstract Nowadays, the rising interest in using renewable energy for thermal power generation has led to radical changes in steam turbine design practice and operability. Modern steam turbines are required to operate with greater flexibility due to rapid load changes, fast start-up, and frequent shutdowns. This has given rise to great challenges to the exhaust hood system design, which has a great influence on the overall turbine performance converting the kinetic energy leaving the last stage of LP turbine into static pressure. The radial hoods are characterized by a complex aerodynamic behavior since the flow turns by 90° in a very short distance and this generates a highly rotational flow structure within the diffuser and exhaust hood outer casing, moreover, the adverse pressure gradient can promote the flow separation drastically reducing the hood recovery performance. For these reasons it is fundamental to design the exhaust system in order to ensure a good pressure recovery under all the machine operating conditions. This paper presents a Design of Experiment analysis on a low-pressure steam turbine exhaust hood through CFD simulations. A parametric model of an axial-radial exhaust hood was developed and a sensitivity of exhaust hood performance as a function of key geometrical parameters was carried out, with the aim of optimizing the pressure recovery coefficient and minimizing the overall dimensions of the exhaust casing. Since hood performance strongly depends on a proper coupling with the turbine rear stage, such a stage was modeled using the so-called mixing-plane approach to couple both stator-rotor and rotor-diffuser interfaces. A detailed analysis of the flow field in the exhaust hood in the different configurations was performed, detecting the swirling structures responsible for the energy dissipation in each simulation, as well as correlating the flow field with the pressure recovery coefficient.

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