Wing is the same as general object likeness, also have attrition obstruction and the obstruction that press difference. To wing, this both closes say " wing section obstruction " . Outside wing section obstruction is being removed on wing, still have " revulsive obstruction " (cry again " inductive instruction " ) . This is a kind of obstruction with wing particular place. Because this kind of obstruction is companion,arise as the generation that strength cites on wing. Perhaps can be in order to say it to produce a kind of price that cite strength and pays.
If a plane is greeting horny A to make horizontal flight with some, the intensity of pressure above its wing will be reduced, and the intensity of pressure below heighten, in the sky increase gas attrition power, arose to lift force Y then. This is air current action the force to wing, according to interplay law, necessarily a counterforce loses the power that raise a sword namely (- Y) , go up to air current by wing action, its direction is down, make air current is down a turn so an angle A, this one angle cries " next washing horn " . As next occurrence that wash horn, appeared to enrage the speed below flow direction at the same time. This one speed is called " next washing fast (W) " . The existence that washs below still can be observed by wind tunnel experiment come out.
By the experiment knowable: When the airlines flies, intensity of pressure of face leaving a wing is great, go up alar face intensity of pressure is little. The length that extends as a result of the ala is finite, so the intensity of pressure of fluctuation ala face officials post so that air current bypasses from face leaving a wing two upright wingtip, up alar face flows. Circle when air current when shedding wingtip, in wingtip there form ceaselessly vortical. Vortical the air that rotates namely is round. Fly to ahead as the plane, vortical from wingtip rearward flow, arose to be down next washing fast (W) . Wash below fast be in in two wingtip the biggest, reduce gradually to the center, decrease in central part the smallest. Because,this is vortical and OK revulsive the air all around rotates subsequently, and this is the effect that as a result of air agglutinant place has. When air is rotating, rely on inner ring more, rotate more quickly, rely on outer lane more, rotate slower. Accordingly, further from wingtip, air current is perpendicular be down next washing fast smaller.
Of graphic representation is certain ala section plane go up next washing speed. V comprised it and relative before speed to add up to speed U. The included angle of U and V issues the A1 that wash horn namely. Horn is washed to make below original strong role A was reduced. Case so according to lifting force Y justice, it answers as perpendicular as relative speed V, after but air current flows,crossing wing, because play the effect that washs fast W, make the direction of V is changed, be down a turn a next A1 that wash horn, and become U. Accordingly, the Y that cite strength also ought to deflexion one angle A1, and as perpendicular as U become Y1. Horn is washed below here very small, consequently Y and Y1 can regard as commonly equal. Time at this moment the plane still advances along the direction of original V. Y1 both neither is the same as original speed V perpendicular, there is one on its necessarily umbriferous for Q; . Its direction and plane flight way are opposite, the effect that has is the advancement of plane of block the way. It is a kind of obstruction actually. This kind of obstruction is by what cite strength revulsive and of generation, because this is called " revulsive obstruction " . Because the additional resistance that makes lift force deflexion so and be caused is washed below air current,it is, do not include it is in wing section obstruction.
A before the wing in the graph small arrowhead represents original velocity of flow, the deflexion after a from the back small arrowhead expresses to had shed wing the velocity of flow of an angle. Revulsive obstruction is the same as the planar appearance of wing, appearance of alar section plane, exhibit bowstring comparing, lift force to concern together especially.
