A M3TEOD OF RAPIDLY ESTI1dATING THE POSIT103 OF THE LAMINAR SEPARATION POINT

A method is described of rapfdly estimating the posi-tion of the laminar separation point from the given pres-sure distribution along a body; the method is applicable to a fairly wide variety of cases. The laminar separation point is found by the von K&man-Millikan method for a series of velocity distributions along a flat plate, wh$ch consist of a region of uniform velocity followed by a re-gion of uniformly decreasing velocity. It is shown that such a velocity distribution can frequently replace the actual velocity distribution along a body insofar as the effects on laminar separation are concerned. An example of the application of the method is given by using it to calculate the position of the laminar sep-aration point on the N.A.C.A. 0012 airfoil section at zero lift. The agreement between the position of the separa-tion point calculated according to the present method asd that found from more elaborate computations is very good. INTRODUCTIOK.-Of the various available methods of calculating the characteristics of the laminar boundary layer in two-dimensional flow and, in particular, the position of the laminar separation point, the van Karman-Millikan method (referonce 1) seems to be the most reliable. This method, when applied to the boundary-layer flow about an elliptic cylinder, showed good agreement with experiment when Father methods failed (reference 2). The von HBrm&n-Wfllikan method, however, has the disadvantage that the computa-tions are usually cumbersome and lengthy. Because of th