Numerical Investigation of Wind Turbine Airfoils under Clean and Dusty Air Conditions

This paper focuses on the simulation of the airflow around wind turbine airfoils (S809 and S814) under both clean and dusty air conditions by using Computational Fluid Dynamics (CFD). The physical geometries of the airfoils and the meshing processes are completed in the ANSYS Mesh package ICEM. The simulation is done by ANSYS FLUENT. For clean air condition, Spalart– Allmaras (SA) model and realizable k-ε model are used. The results are compared with the experimental data to test which model agrees better. For dusty air condition, simulation of the two-phase flow is operated by realizable k-ε model and discrete phase model (DPM) in different concentration of dust particles (1% and 10% in volume). The results are compared with the data of clean air to illustrate the effect of dust contamination on the lift and drag characteristics of the airfoil

Numerical Investigation of Wind Turbine Airfoils under Clean and Dusty Air Conditions

The focus of research in this thesis is on numerical simulation of airflow around wind turbine airfoils (S809, S814 and S1210) under both clean and dusty air conditions by using Computational Fluid Dynamics (CFD). The physical geometries of the airfoils and the meshing processes are completed in the ANSYS Mesh package ICEM. The simulations and post-processing are done by ANSYS FLUENT. For cases of clean air condition, Spalart–Allmaras (SA), realizable k-ε and Wray-Agarwal (WA) turbulence models are employed in the calculations. The results are compared with the experimental data for validation. For dusty air condition, simulation of the two-phase flow is conducted using the discrete phase model (DPM) for various concentrations of dust particles using the realizable k-ε model and WA turbulence models. The results are compared with the clean air simulations to illustrate the effect of dust contamination on the aerodynamic performance of the airfoils. Finally, some conclusions are drawn on how several factors influence the aerodynamic performance of the airfoils and suggestions are made to improve the wind energy conversion efficiency of airfoils under clean and dusty air conditions

Aerodynamic Performance of a NREL S809 Airfoil in an Air-Sand Particle Two-Phase Flow

This paper opens up a new perspective on the aerodynamic performance of a wind turbine airfoil. More specifically, the paper deals with a steady, incompressible two-phase flow, consisting of air and two different concentrations of sand particles, over an airfoil from the National Renewable Energy Laboratory, NREL S809. The numerical simulations were performed on turbulence models for aerodynamic operations using commercial computational fluid dynamics (CFD) code. The computational results obtained for the aerodynamic performance of an S809 airfoil at various angles of attack operating at Reynolds numbers of Re = 1 × 106 and Re = 2 × 106 in a dry, dusty environment were compared with existing experimental data on air flow over an S809 airfoil from reliable sources. Notably, a structured mesh consisting of 80,000 cells had already been identified as the most appropriate for numerical simulations. Finally, it was concluded that sand concentration significantly affected the aerodynamic performance of the airfoil; there was an increase in the values of the predicted drag coefficients, as well as a decrease in the values of the predicted lift coefficients caused by increasing concentrations of sand particles. The region around the airfoil was studied by using contours of static pressure and discrete phase model (DPM) concentration