A faster 'transition' to laminar flowA discussion is given of the ongoing research related to laminar flow airfoils, nacelles, and wings where the laminar flow is maintained by a favorable pressure gradient, surface suction or a combination of the two. Design methologies for natural laminar flow airfoil sections and wings for both low and high speed applications are outlined. Tests of a 7-foot chord, 23-deg sweep laminar flow-control airfoil at high subsonic Mach numbers are described, along with the associated stability theory used to design the suction system. The state-of-the-art of stability theory is simply stated and a typical calculation illustrated. In addition, recent computer simulations of transition using the time dependent Navier-Stokes equations are briefly described. Advances in wind tunnel capabilities and instrumentation will be reviewed, followed by the presentation of a few results from both wind tunnels and flight. Finally, some suggestions for future work will complete the paper.
Document ID
19860053609
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Bobbitt, P. J. (NASA Langley Research Center Hampton, VA, United States)
Waggoner, E. G. (NASA Langley Research Center Hampton, VA, United States)
Harvey, W. D. (NASA Langley Research Center Hampton, VA, United States)
Dagenhart, J. R. (NASA Langley Research Center Hampton, VA, United States)