Analysis of the Performance of a Wind-Turbine Airfoil under Heavy-Rain Conditions Using a Multiphase Computational Fluid Dynamics Approach

Abstract

A novel multiphase computational fluid dynamics model based on the coupled Lagrangian−Eulerian approach was developed to assess the performance of the S809 airfoil of a horizontal-axis wind turbine under rainy conditions. The model was utilized for simulations of water film formation over the airfoil. Our simulation showed significant performance loss due to an increase in drag and lift degradation.

High Humidity Aerodynamic Effects Study on Offshore Wind Turbine Airfoil/Blade Performance through CFD Analysis

“…It can be seen that, with the increase of humidity, the lift coefficient decreases, the drag coefficient increases, and the lift drag ratio decreases. The similar results were shown with heavy rain fall study from [7][8][9][10]. Because the drag coefficient is larger than other models, there may be some uncertainties;…”

“…wherėis volumetric mass source (kg/m 3 ⋅s). Equations (8) are used as a source terms within the source code of the UDF (Table 2).…”

CFD simulation of the effect of rain on the performance of horizontal wind turbines

“…To develop a comprehensive model to simulate the motion of rain droplets before they enter the water layer, the formation of the water layer from rain droplets on the wind turbine airfoils, and flow of the air and water layer on the surface of the turbine airfoils, two multiphase models (Lagrangian DPM and the Eulerian VOF model) were used (Cai et al and Cohan and Arastoopour). In the Lagrangian DPM model, the fluid phase is treated as a continuum, while the dispersed phase is solved by tracking the rain droplets through the calculated flow field.…”

“…The formation of the water layer on the surface of the airfoils was not considered in these studies. Later on, Cai et al used CFD models to simulate the formation of a water layer due to rain on the surface of a two‐dimensional (2D) airfoil from the rain droplets. They included in their model a continuous addition of rain droplet mass on the water layer on the surface of their 2D airfoil by coupling the Lagrangian discrete phase model (DPM) for rain droplets with a Eulerian volume of fluid (VOF) model for the water layer flow on the surface of an airfoil.…”

“…They included in their model a continuous addition of rain droplet mass on the water layer on the surface of their 2D airfoil by coupling the Lagrangian discrete phase model (DPM) for rain droplets with a Eulerian volume of fluid (VOF) model for the water layer flow on the surface of an airfoil. Recently, Cohan and Arastoopour further improved the Cai et al model by adding the surface tension and the rain droplet total momentum in addition to droplet mass to simulate the effect of lift and drag forces exerted on an airfoil due to rain.…”