Stability of spatially developing boundary layers

A new formulation of the stability of boundary layer flows in pressure gradients is presented, taking into account the spatial development of the flow . The formulation assumes that disturbance wavelength and eigenfunction vary downstream no more rapidly than the boundary layer ,13; thickness, and includes all terms of 0..(1). and O (R-1) in the boundary layer Reynolds numbs= R . Although containing the Q.rr-amp;ommerfeld operator, -the present approach does not yield the Qrr-Scn erf eld equation in any rational limit, InBlasius flow, the present stability equation is consistent with tthat of Bertolotti et al . (1992) to terms of Q(R- ).For the Falkner-Skan similarity solutions neutral boundaries are computed without the necessity of having to march in space . . Results show that the effects of spatial growth are striking in flows subjected to adverse pressure gradients