There has been considerable success in the design of practical low-speed natural laminar flow (NLF) airfoils, with significant profile drag reduction from conventional turbulent flow airfoils. The favorable lowspeed results give an incentive to explore the possibilities of high-subsonic speed NLF airfoil design. The design problem at higher freestream Mach numbers is more severe than for low-speed designs because these high-speed airplanes typically fly at higher chord Reynolds numbers than low-speed NLF airplanes. As the Mach number increases, the main priority changes from the use of sufficient acceleration to achieve NLF for low-drag, to the delay of separation in the far aft pressure recovery region. In this effort, NLF airfoils have been designed for Mach numbers ranging from 0.60 to 0.80 and chord Reynolds numbers of 30 x 10 to the 6th and 40 x 10 to the 6th.
Design limits of compressible NLF airfoils
1991-01-01
Conference paper
No indication
English