scholarly journals A Rationalised CFD Design Methodology for Turgo Turbines to Enable Local Manufacture in the Global South

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6250
Author(s):  
Joe Butchers ◽  
Shaun Benzon ◽  
Sam Williamson ◽  
Julian Booker ◽  
George Aggidis
Keyword(s):  
Global South ◽  
Local Context ◽  
Multiphase Model ◽  
Operational Parameters ◽  
Design Changes ◽  
Ansys Cfx ◽  
Commercial Code ◽  
Technological Developments ◽  
Turbine Design ◽  
Hydropower Industry

In the Global South, pico- and micro-hydropower turbines are often made by local workshops. Despite several advantageous features, e.g., a high power density and capacity to handle silt, there is no commonly available Turgo turbine design appropriate for local manufacture. Technological developments including the internet, CAD, and additive manufacturing increase the opportunity to precisely transfer designs around the world. Consequently, design improvements can be shared digitally and used by manufacturers in their local context. In this paper, a rationalised CFD approach was used to guide simple design changes that improve the efficiency of a Turgo turbine blade. The typical manufacturing capacity of the micro-hydropower industry in Nepal was used to rationalise the variation of potential design changes. Using the geometry and operational parameters from an existing design as a benchmark, a two-blade, homogenous, multiphase model was developed and run using the commercial code ANSYS CFX. Initially, it was identified that the jet aim position had a significant effect on the efficiency. A design of experiments’ approach and subsequent analysis of numerical and visual results were used to make design changes that resulted in an improvement in efficiency from 69% to 81%. The design changes maintained the simple profile of the blade, ensuring that the resulting design was appropriate for manufacture in a local workshop.

scholarly journals Radial Turbine Design for Solar Chimney Power Plants

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 674
Author(s):  
Paul Caicedo ◽  
David Wood ◽  
Craig Johansen
Keyword(s):  
Power Plants ◽  
Reference Frames ◽  
Three Dimensional ◽  
Discrete Ordinates ◽  
Large Area ◽  
Solar Chimney ◽  
Cfd Simulations ◽  
Radial Turbine ◽  
Design Changes ◽  
Turbine Design

Solar chimney power plants (SCPPs) collect air heated over a large area on the ground and exhaust it through a turbine or turbines located near the base of a tall chimney to produce renewable electricity. SCPP design in practice is likely to be specific to the site and of variable size, both of which require a purpose-built turbine. If SCPP turbines cannot be mass produced, unlike wind turbines, for example, they should be as cheap as possible to manufacture as their design changes. It is argued that a radial inflow turbine with blades made from metal sheets, or similar material, is likely to achieve this objective. This turbine type has not previously been considered for SCPPs. This article presents the design of a radial turbine to be placed hypothetically at the bottom of the Manzanares SCPP, the only large prototype to be built. Three-dimensional computational fluid dynamics (CFD) simulations were used to assess the turbine’s performance when installed in the SCPP. Multiple reference frames with the renormalization group k-ε turbulence model, and a discrete ordinates non-gray radiation model were used in the CFD simulations. Three radial turbines were designed and simulated. The largest power output was 77.7 kW at a shaft speed of 15 rpm for a solar radiation of 850 W/m2 which exceeds by more than 40 kW the original axial turbine used in Manzanares. Further, the efficiency of this turbine matches the highest efficiency of competing turbine designs in the literature.

Effects of Stator Configurations on the Flotation Performance of Induced Gas Flotation Machine

2016 ◽  
Author(s):  
Ji-Gu Lee ◽  
Ji-Yun Kang ◽  
Youn-Jea Kim
Keyword(s):  
Flow Characteristics ◽  
Chemical Plants ◽  
Oil Sand ◽  
Two Phase ◽  
Ansys Cfx ◽  
Commercial Code ◽  
Flotation Cell ◽  
Flotation Performance ◽  
Forced Air ◽  
Phase Water

Induced Gas Flotation (IGF) vessel is used for water treatment of plant industries such as oil sand and chemical plants. An understanding of the interaction between the stator and rotor is essential for the design of IGF with consideration of geometric blade configuration is essential for the design of IGF. In this study, the effect of the number of stator blades on flotation performance was numerically investigated using the commercial code, ANSYS CFX ver. 16.1. The two-phase (water and air) flow characteristics in the forced-air mechanically stirred Dorr-Oliver flotation cell were considered. The flotation performance was evaluated on the basis of the correlations among the number of stator blades (8, 12, 16, 20, 24), power number and void fraction. By comparing the result of each case, the newly designed model with 12 stator blades which had the highest flotation performance was derived.

scholarly journals UPWARD FLOW AND HEAT TRANSFER AROUND TWO HEATED CIRCULAR CYLINDERS IN SQUARE DUCT UNDER AIDING THERMAL BUOYANCY

2020 ◽  
Vol 14 (1) ◽  
pp. 113-123
Author(s):  
H. Laidoudi
Keyword(s):  
Heat Transfer ◽  
Convection Heat Transfer ◽  
Circular Cylinders ◽  
Upward Flow ◽  
Square Duct ◽  
Thermal Buoyancy ◽  
Flow And Heat Transfer ◽  
Ansys Cfx ◽  
Commercial Code ◽  
Physical Phenomena

This paper presents a numerical investigation of mixed convection heat transfer around a pair of identical circular cylinders placed in side-by-side arrangement inside a square cavity of single inlet and outlet ports. The investigation provided the analysis of gradual effect of aiding thermal buoyancy on upward flow around cylinders and its effect on heat transfer rate. For that purpose, the governing equations involving continuity, momentum and energy are solved using the commercial code ANSYS-CFX. The distance between cylinders is fixed with half-length of cavity. The simulation is assumed to be in laminar, steady, incompressible flow within range of following conditions: Re = 1 to 40, Ri = 0 to 1 at Pr = 0.71. The main obtained results are shown in the form of streamline and isotherm contours in order to interpret the physical phenomena of flow and heat transfer. The average Nusselt number is also computed and presented. It was found that increase in Reynolds number and/or Richardson number increases the heat transfer. Also, aiding thermal buoyancy creates new form of counter-rotating zones between cylinders.

Computational Modeling of Interaction Between Actions and Action Effects of FPSO Topside Structures Subject to Jet Fire

2010 ◽  
Author(s):  
G. M. Katsaounis ◽  
D. Katsourinis ◽  
M. S. Samuelides ◽  
M. Founti ◽  
Jeom Kee Paik ◽  
...  
Keyword(s):  
Computational Modeling ◽  
Constitutive Relations ◽  
Finite Element Program ◽  
Effect Analysis ◽  
Ansys Cfx ◽  
Commercial Code ◽  
Time Histories ◽  
Element Program ◽  
Computational Fluid Dynamics Cfd ◽  
Nonlinear Elastic

This paper presents a computational modeling of accidental fire actions on the topside structures of a floating, production, storage and offloading (FPSO) unit. According to the assumed scenario, the accident results in a jet fire, which loads the structure by temperature increments and pressures generation on their exposed surfaces. Temperature distributions were obtained by computational fluid dynamics (CFD) simulations, using the ANSYS CFX commercial code. The temperature versus time histories computed were first approximated (idealized) by smoother curves, based on fewer time-points, while retaining the maximum and minimum values. A similar procedure was also followed for the pressure variations. For the consequence (action effect) analysis the LSDYNA nonlinear finite element program was employed and the structures were modeled using shell finite elements with nonlinear (elastic-thermal plastic) constitutive relations. On the structure surfaces non coinciding grids were used for the two kinds of analyses (i.e., the CFD and FEM), in order to accommodate the diverse requirements of the different problems. The procedure of assignment the pressure and temperature loadings directly from the CFD results to the FEM model is described and representative results are given through the application of the methodology to a sample problem.

Numerical Investigation of Aerodynamic Performance of a Three-Bladed Vertical Axis Wind Turbine

2010 ◽  
Author(s):  
Alexandrina Untaroiu ◽  
Lydia R. Barker ◽  
Houston G. Wood ◽  
Robert J. Ribando ◽  
Paul E. Allaire
Keyword(s):  
Wind Turbine ◽  
Cfd Simulation ◽  
Vertical Axis ◽  
Operating Speed ◽  
University Of Virginia ◽  
Vertical Axis Wind Turbine ◽  
Start Up ◽  
Ansys Cfx ◽  
Turbine Design ◽  
The University

As a pollution free source of energy, wind is among the most popular and fastest growing forms of electricity generation in the world. Compared to their horizontal axis counterparts, vertical axis wind turbines have lagged considerably in development and implementation. The University of Virginia Rotating Machinery and Controls laboratory has undertaken a systematic review of vertical axis wind turbine design in order to address this research gap, starting with establishment of a methodology for vertical axis wind turbine simulation using ANSYS CFX. A 2D model of a recently published Durham University vertical axis wind turbine was generated. Full transient CFD simulations using the moving mesh capability available in ANSYS-CFX were run from turbine start-up to operating speed and compared with the experimental data in order to validate the technique. A scalable k-ε turbulence model transient CFD simulation has been demonstrated to accurately predict vertical axis wind turbine operating speed within 12% error using a two-dimensional structured mesh in conjunction with a carefully specified series of boundary conditions.

Effect of Guide Vane Angle on Wells Turbine Performance

2014 ◽  
Author(s):  
Paresh Halder ◽  
Abdus Samad
Keyword(s):  
Guide Vane ◽  
Vortex Formation ◽  
Energy System ◽  
Flow Coefficient ◽  
Wells Turbine ◽  
Turbine Performance ◽  
Ansys Cfx ◽  
Commercial Code ◽  
Stagger Angle ◽  
Vane Angle

Wells turbines are used in oscillating water column wave energy system and the turbine has a stagger angle of 90°. Numerical analysis is performed to analyze the performance of the turbine in the present work. A commercial code ANSYS-CFX® v14.0 was used for the simulations at different flow coefficient, different angles and a constant rotational speed. The turbulence model was k-ω SST. Higher guide vane angle produced higher efficiency of the turbine and the efficiency (enhanced) change was contributed because of the vortex formation in different locations in the flow passage or near the blade surface.

Numerical and Experimental Investigation of a Low Order Radial Turbine Model for Engine-Level Optimisation of Turbocharger Design

2020 ◽  
Author(s):  
Karl Hohenberg ◽  
Ricardo Martinez-Botas ◽  
Piotr Łuczyński ◽  
Carola Freytag ◽  
Manfred Wirsum
Keyword(s):  
Design Parameters ◽  
Test Results ◽  
Baseline Design ◽  
Design Changes ◽  
High Power Operation ◽  
Loss Models ◽  
Turbine Design ◽  
Development And Validation ◽  
Wide Operating ◽  
Turbine Model

Abstract This paper presents the development and validation of a meanline model by means of numerical and experimental methods, to determine it’s feasibility as an optimisation tool for turbocharger matching. Using a parametric turbine model, numerical experiments were conducted accounting for variations of several key turbine design parameters and a wide operating range. The resulting dataset was used to test the accuracy of the meanline model when calibrated to a baseline design and thus evaluate it’s ability of extrapolating to different designs. The loss models were examined in more detail, and a set of loss models which provided the most accurate results is presented. The meanline model was further validated experimentally using dynamometer test results of 6 turbine designs from the same parametric turbine model. The result showed that for design point and high power operation, an error of less than 3.1% and 2.0% was achieved for efficiency and mass flow parameter respectively. This led to the conclusion that the model would be sufficiently accurate to represent design changes relevant to turbocharger matching.

scholarly journals Experimental and numerical tip leakage flow visualization in the LP turbine labyrinth seal

2019 ◽  
Vol 137 ◽  
pp. 01008
Author(s):  
Krzysztof Bochon ◽  
Włodzimierz Wrόblewski ◽  
Artur Szymański ◽  
Mirosiaw Majkut ◽  
Michał Strozik ◽  
...  
Keyword(s):  
Pressure Ratio ◽  
Main Idea ◽  
Labyrinth Seal ◽  
Tip Leakage Flow ◽  
Pressure Losses ◽  
Low Pressure Turbine ◽  
Flow Parameters ◽  
Ansys Cfx ◽  
Commercial Code ◽  
Lp Turbine

The subject of this publication is the identification of basic flow parameters and flow structures in the seal experimentally and compare them with CFD results. A straight-through seal with two leaning fins and smooth or honeycomb land was analysed. The sealing concept is characteristic for the tip seal of the last stage of an aircraft low-pressure turbine. Due to the limitations of the test rig the analyses presented here were conducted on a highly simplified, stationary model of the seal itself, with an axial inflow and no curvature in the circumferential direction. The characteristics of the discharge coefficient as a function of the pressure ratio for different clearances and the pressure distribution along the seal, for different pressure ratios are presented. In addition, an attempt was made to visualize the flow using the schlieren technique. The main idea of application schlieren photography was to observe the vortex and separation structures occurring during the flow through the labyrinth seal, which is the major source of pressure losses. CFD calculations were carried out using the Ansys CFX commercial code.

Numerical Analysis of Turbulent Flow Over a Wavy Wall in a Channel

2016 ◽  
Author(s):  
Vinicius Martins Segunda ◽  
Scott Ormiston ◽  
Mark Tachie
Keyword(s):  
Turbulent Flow ◽  
Turbulence Models ◽  
Moment Closure ◽  
Recirculation Region ◽  
Wavy Wall ◽  
Viscosity Models ◽  
Ansys Cfx ◽  
Commercial Code ◽  
Flow Phenomena ◽  
Second Moment Closure

A commercial CFD code (ANSYS CFX, release 16.2) is used to predict the turbulent flow phenomena over a wavy wall. The present work will provide numerical simulations of flow in a channel with a wavy lower wall using a variety of turbulence models available in the CFD commercial code. Eddy viscosity models and Second Moment Closure models were used with wall function available. Those turbulence models had different predictions for the flow field, in which were evaluated: velocity profiles, pressure distribution, wall shear stress, recirculation region and turbulence quantities. A comparison between their predictions will be presented. The validation of results is performed by comparison to experimental data from previous studies and also LES simulations.

Numerical Study on the Flow Characteristics of the Francis Turbine With Various Blade Profiles

2013 ◽  
Author(s):  
J.-H. Jeon ◽  
S.-S. Byeon ◽  
Y.-J. Kim
Keyword(s):  
Stokes Equations ◽  
Numerical Study ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Francis Turbine ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Ansys Cfx ◽  
Commercial Code ◽  
Sst Turbulence Model

The Francis turbine is a kind of reaction turbines, which means that the potential energy of water converted to rotational kinetic energy. In this study, the flow characteristics have been investigated numerically in a Francis turbine on the 15 MW hydropower generation with various blade profiles (NACA 65 and NACA 16 series) and discharge angles (14°, 15°, 17°, and 18°), using the commercial code, ANSYS CFX. The k-ω SST turbulence model is employed in the Reynolds averaged Navier-Stokes equations. The computing domain includes the spiral casing, guide vanes, and draft tube, which are discretized with a full three-dimensional mesh system of unstructured tetrahedral shapes. The results showed that the change of blade profiles and discharge angles significantly influenced the performance of the Francis turbine.

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