In present work numerical two dimensions, steady, incompressible,
turbulent flow past S809 wind turbine airfoil with microtab at 95% of chord length
of leading edge in lower surface is analyzed by Fluent (6.2) program for model
consists of S809 airfoil without and with microtab at 95% of chord line have height
1.1% and other 2% of chord length undergo to turbulent flow k-. model, the flow
has Reynolds number is 106. The results are represented by velocity contour and
vector. Aerodynamic coefficients are drawn in graph. The results are showed an
increase lift and drag coefficient in existence microtab locate 95% of chord at it's
height 1.1% and 2% of chord to range of attack angle (0, 5, 10, 15, 20) degrees.
The results compare with experimental data of standard airfoil and existence 1.1%
chord length microtab and it is approximately good. Values of lift & drag
coefficient are increased for the existence of 1.1% chord length microtab while in
case the existence of microtab 2% chord length lift coefficient increased which it's
max. increment by 46% while, drag coefficient decreased it's min. increment to be
26% but not full range of attack angle.