Boundary Layer Stability Analysis of a Natural Laminar Flow Glove on the F-111 TACT Airplane

A natural laminar flow airfoil has been developed jointly by NASA's Dryden Flight Research and Langley Research Centers as a part of the aircraft energy efficiency (ACEE) program. A NASA flight program incorporating this airfoil into partial wing gloves on the F-111 TACT airplane was scheduled to start in May, 1980. In support of this research effort, Boeing has conducted an extensive boundary layer stability analysis of the partial glove. The results of the analysis show the expected effects of wing leading-edge sweep angle, Reynolds number, and compressibility on boundary layer stability and transition. These results indicate that it should be possible to attain on the order of 60% laminar flow on the upper surface and 50% laminar flow on the lower surface for sweep angles of at least 20 deg. chord Reynolds numbers of 25 x 106 and Mach numbers from 0.81 to 0.85.