Abstract: Boundary layer control on thick airfoils or airfoils at large angle of attack, whichuses very small power input, is studied. The control method is to use multiple slots on the airfoilupper surface tangentially blowing at small speeds. Boundary layer loses its kinetic energy dueto wall friction and adverse pressure gradient gradually along airfoil surface. Therefore, supplyinga small amount of energy at each of the slots located along the airfoil upper surface energizesthe boundary layer and suppresses the s...