Influence of Turbulence Model for Wind Turbine Simulation in Low Reynolds Number

Masami Suzuki

doi:10.1155/2016/8072078

Abstract

In designing a wind turbine, the validation of the mathematical model’s result is normally carried out by comparison with wind tunnel experiment data. However, the Reynolds number of the wind tunnel experiment is low, and the flow does not match fully developed turbulence on the leading edge of a wind turbine blade. Therefore, the transition area from laminar to turbulent flow becomes wide under these conditions, and the separation point is difficult to predict using turbulence models. The prediction precision decreases dramatically when working with tip speed ratios less than the maximum power point. This study carries out a steadiness calculation with turbulence model and an unsteadiness calculation with laminar model for a three-blade horizontal axis wind turbine. The validation of the calculations is performed by comparing with experimental results. The power coefficients calculated without turbulence models are in agreement with the experimental data for a tip speed ratio greater than 5.

Highlights

Computational fluid dynamics (CFD) modeling and experiments both have advantages and disadvantages
CFD is more advantageous for predictions where experiments are difficult to carry out, for example, free stream conditions, it is generally difficult to obtain reliable results compared with experimental data
CFD is an efficient tool for turbomachinery and can complement uncertain experimental results [1]

Summary

Introduction

Computational fluid dynamics (CFD) modeling and experiments both have advantages and disadvantages. CFD is more advantageous for predictions where experiments are difficult to carry out, for example, free stream conditions, it is generally difficult to obtain reliable results compared with experimental data. CFD with and without a turbulence model have been attempted to solve for wind turbine performance and provide data for various detailed characteristics. In this paper, they are attempted to solve for more accurate characteristics of a wind turbine in the shortest time possible even on a personal computer, using coarse grid. Experiments clear and to make the calculation results contribute to the improvement of experimental method

Numerical Methods

General Performance

Findings

Detailed Characteristics