Dust Effect on the Performance of Wind Turbine Airfoils

Abstract

The full two-dimensional Navier-Stokes algorithm and the SST k-? turbulence model were used to investigate incom-pressible viscous flow past the wind turbine two-dimensional airfoil under clean and roughness surface conditions. The NACA 63-430 airfoil is chosen to be the subject, which is widely used in wind turbine airfoil and generally located at mid-span of the blade with thickness to chord length ratio of about 0.3. The numerical simulation of the airfoil under clean surface condition has been done. As a result, the numerical results had a good consistency with the experimental data. The wind turbine blade surface dust accumulation according to the operational periods in natural environment has been taken into consideration. Then, the lift coefficients and the drag coefficients of NACA 63-430 airfoil have been computed under different roughness heights, different roughness areas and different roughness locations. The role that roughness plays in promoting premature transition to turbulence and flow separation has been verified by the numeri-cal results. The trends of the lift coefficients and the drag coefficients with the roughness height and roughness area increasing have been obtained. What’s more, the critical values of roughness height, roughness area, and roughness location have been proposed. Furthermore, the performance of the airfoil under different operational periods has been simulated, and an advice for the period of cleaning wind turbine blades is proposed. As a result, the numerical simula-tion method has been verified to be economically available for investigation of the dust effect on wind turbine airfoils

External lightning protection system for wind turbine blades — preliminary aerodynamic results

“…protrusion) sensitivity studies (or designing one) [7,8,12,17]. Furthermore, the pressure coefficient distribution also provides useful information when considering aerofoil profiles modification (or alteration) to achieve a specific objective.…”

“…Furthermore, the pressure coefficient distribution also provides useful information when considering aerofoil profiles modification (or alteration) to achieve a specific objective. Normally, in aerofoil profiles modification, different aerofoil profiles are being compared (in terms of pressure coefficient distribution) and altered (or perhaps fine-tuned) to achieve better lift to drag ratio [7,8,12,18,19] (e.g. glider, wind turbine blade).…”

“…Previous experimental and numerical findings by other researchers addressed surface roughness due to ice accretion and dust accumulation on aerofoil surfaces; particularly on the leading edge where the roughness was just below 1 mm [7,8]. On the other hand, the Standards [1] has recommended that the typical cross section for down conductor is 50 mm 2 when considering lightning protection system.…”

A Damage Assessment for Wind Turbine Blades from Heavy Atmospheric Particles

“…Moreover particle collision, temperature jumps and freeze-thaw cycles may cause smaller coating cracks to propagate, promoting coating removal and eventually delamination and corrosion damage due to exposure of the internal composite structure. The originally smooth surface of the blades may change considerably, and the increased roughness will cause a drop of gross annual energy production (GAEP) and an increase in cost of energy (COE) [7][8][9][10][11][12][13] .…”

Optimization of Wind Turbine Airfoils Subject to Particle Erosion

“…The originally smooth surface of the blades may change considerably, and the increased roughness will cause a drop in gross annual energy production (GAEP) and an increase in cost of energy (COE). [7][8][9][10][11][12][13] Modern trends in the wind turbine market have shown the benefits of offshore megawatt-scale wind turbine installations 14,15 in order to maximize GAEP while reducing COE. However, offshore locations are subject to more intense sand erosion than the majority of land installations.…”