Wells turbines are used in oscillating water column wave energy system and the turbine has a stagger angle of 90o. Numerical analysis is performed to analyze the performance of the turbine in the present work. A commercial code ANSYSCFX ® 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. Copyright © 2014 by ASME.

Abdus Samad

Department of Ocean Engineering

Paresh Halder

Axial flow turbomachinery

Gas turbines

Hydraulic turbines

Turbomachine blades

Turbulence models

Vortex flow

WAVE ENERGY CONVERSION

Axial flow turbines

CONSTANT ROTATIONAL SPEED

Flow coefficients

GUIDE VANE

Higher efficiency

OSCILLATING WATER COLUMN

Tip clearance

WELLS TURBINE

TURBINE COMPONENTS

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Effect of Guide Vane Angle on Wells Turbine Performance

ASME 2014 Gas Turbine India Conference, GTINDIA 2014

Guide vanes (GVs) improve the performance of a turbine in terms of efficiency, torque, or operating range. In this work, a concept of different orientations of GVs in between a two-row biplane wells turbine (BWT) was introduced and analyzed for the performance improvement. The fluid flow was simulated numerically with a commercial software ANSYS CFX 16.1. The Reynolds-averaged Navier-Stokes equations with the k-Ï ‰ turbulence closure model were solved for different designs and flow conditions. For the base model, the results from simulation and experiments are in close agreement. Among the designs considered, the configuration, where the blades are in one line (zero circumferential angle between blades of two plane) and the midplane guide vane has concave side to the leading edge of the blade, performed relatively better. However, the performance was still less compared to the base model. The reason behind the reduction in performance from the base model is attributed to the blockage of flow and the change of flow path occurring due to the presence of the midplane GVs. The flow analysis of different cases and the comparison with the base model are presented in the current study. © 2019 by ASME.

Journal of Fluids Engineering, Transactions of the ASME

The effect of midplane guide vanes in a biplane wells turbine

Wells turbine is a self-rectifying airflow turbine capable of converting pneumatic power of the periodically reversing air stream in oscillating water column into mechanical energy. This paper reports the computational analysis on performance and aerodynamics of Wells turbine with the NACA 0021 constant chord blades. Studies have been made at various flow coefficients covering the entire range of flow coefficients over which the turbine is operable. The present computational model can predict the performance and aerodynamics of the turbine quantitatively and qualitatively. The model also predicted the flow coefficient at which the turbine stalls, with reasonable accuracy. © 2005 Elsevier Ltd. All rights reserved.

Renewable Energy

Computational analysis of performance and flow investigation on wells turbine for wave energy conversion

Oscillating Water Column based wave energy plants convert wave energy into low pressure pnuematic power in the form of bi-directional air flows. Air turbines which are capable of rotating uni-directionally in bi-directional air flow, otherwise also known as self-rectifying turbines, are used to extract mechanical shaft power which is further converted into electrical power by a generator. This paper reviews the state of the art in self-rectifying impulse air turbines. New results on optimum parameters for the fixed-guide-vane impulse turbine are also presented. Starting characteristics and conversion efficiencies of two types of impulse turbines are compared with the well known Wells turbine. © 2001 Elsevier Science Ltd. All rights reserved.

A review of impulse turbines for wave energy conversion

A Wells turbine has inherent disadvantages: Lower efficiency and poorer starting characteristics. Providing guide vanes on either side of the rotor could be one of the most effective ways of improving its performance. Several papers have demonstrated the usefulness of 2D guide vanes so far. In order to achieve further improvement in the performance of the Wells turbine, the effect of 3D guide vanes has been investigated experimentally by testing a model under steady flow conditions. Then, the running and starting characteristics under irregular flow conditions have been obtained by a computer simulation using quasi-steady analysis. It is found that the running and starting characteristics of the Wells turbine with 3D guide vanes are superior to those with 2D guide vanes. © 2000 Elsevier Science Ltd. All rights reserved.

Effect of guide vane shape on the performance of a Wells turbine

Energy Conversion and Management

Effect of duct geometry on Wells turbine performance

Applied Ocean Research

Numerical investigation on the performance of Wells turbine with non-uniform tip clearance for wave energy conversion

Effect of guide vane angle on wells turbine performance

Journal	ASME 2014 Gas Turbine India Conference, GTINDIA 2014
Publisher	American Society of Mechanical Engineers
Open Access	No