Task 5 Study of Wake Effects Behind Single Turbines and in Wind Turbine Parks

Overview

 

task_5_sm.jpgTask 5 Study of Wake Effects Behind Single Turbines and in Wind Turbine Parks


Duration: 1980-1984

Operating Agent: Netherlands Energy Research Foundation, the Netherlands

Participants: Canada, Denmark, Ireland, Japan, the Netherlands, Sweden, the United Kingdom, the United States

Objectives:

  • Measurements of individual wake structure and decay
  • Measurements of turbine performance in velocity fields of the type that may be encountered in a wake
  • Theoretical and experimental modeling of turbine cluster performance by combining information on individual wakes with knowledge of machine performance in wake-type flows

Progress and Achievements


Experimental wake effect studies were carried out as part of Task 1 Environmental and Meteorological Aspects of Wind Energy Conversion Systems. In Task 5, these studies were extended to cover horizontal-axis turbines and to include field measurements on real wind turbines. Work was performed in three major areas:

  • Measurements of individual wake structure and decay
  • Measurements of turbine performance in velocity fields of the type that may be encountered in a wake
  • Theoretical and experimental modeling of turbine cluster performance by combining information on individual wakes with knowledge of machine performance in wake-type flows

The Task resulted in a wealth of experimental data available to the participants. The data were analyzed and empirical correlations derived. The validity of simulators for wind tunnel tests of clusters was established. The comparison between the experimental results and predictive models for cluster efficiency showed a reasonable agreement. The major uncertainties of the predictive models lie in the equations used to describe the decay of a single wake.