ABOUT THE DEVELOPMENT OF SWEPT LAMINAR SUCTION WINGS WITH FULL CHORD LAMINAR FLOW

Abstract

This chapter discusses the development of swept laminar suction wings with full-chord laminar flow. The characteristics of swept laminar suction wings can be predicted when it is known to what degree the crossflow stability limit Reynolds number, based, for example, on maximum crossflow velocity and boundary layer thickness can be exceeded on such a wing under crossflow conditions without transition. Disturbances in a crossflow boundary layer, being dynamically unstable, grow rapidly in the Reynolds number range beyond the crossflow stability limit. Transition then occurs after exceeding the crossflow stability limit Reynolds number by but a small margin. On a swept laminar suction wing, the crossflow stability limit Reynolds number may be exceeded by a similar or somewhat smaller ratio at various chordwise stations without causing transition. The chordwise suction distribution, for which the crossflow Reynolds number at various chordwise stations is 40 percent higher than the corresponding local crossflow stability limit Reynolds number, can then be determined from calculations of the development and stability of the laminar boundary layer on swept laminar suction wings.