Research Of Airfoil Surface Roughness Effect On The Aerodynamic Performance

With the development of science and technology,energy demand is ever-increasing.At the same time,environment protection is an important problem that we have to confront of. As a green source of energy,Wind is recognized by the society.Adopting wind turbine to generate electricity is the major form of exploiting wind energy to deal with above problems.Blade is one of the most important components of the wind turbine,which costs up to 20% of the whole machine.Airfoil surface roughness is a major factor of influence to the aerodynamic characteristics.Firstly,on the basis of analyzing the development of domestic and foreign and dedicated airfoils for wind turbines, the basic theory of aerodynamics of wind turbine airfoils,including the geometric characteristics of airfoils,the traditional and dedicated wind turbine airfoil series, were described in detail,and various series of airfoil aerodynamic characteristics described.Secondly,DU93-W-210 airfoils are simulated mainly for lift,drag characteristic with the software Fluent.It attested that the selection of the SST k -ωtwo-equation-model as turbulence model can effectively simulating airfoil aerodynamic characteristics.Finally,the influence of airfoil surface roughness on the aerodynamic performance is researched,and the main laws are listed:(1) When the thickness of the airfoil is constant, the aerodynamic performance is more sensitive to the surface roughness for the smaller suction surface thickness near the front edge. There is lower sensitivity to the surface roughness for the thinner airfoils, and higher sensitivity for the thicker ones.(2) When the height of roughness boss on the airfoil surface is bigger than 0.32 mm, the aerodynamic performance will be affected: the lift coefficient will be smaller as the increase of the height of the roughness boss, and the resistance coefficient bigger. The aerodynamic performance lost significantly, and the loss will be more obvious when the roughness boss is bigger.(3) The airfoil aerodynamic performance will be more affected by the roughness near the front edge, and the aerodynamic performance can be directly dropped. The airfoil aerodynamic performance will be less affected by the roughness near the back edge. Especially, the roughness on the trailing edge can promote the aerodynamic performance of the airfoil.