In-Flight Receptivity Experiments on a 30-degree Swept-Wing Using Micron-sized Discrete Roughness Elements Conference Paper uri icon


  • Micron-sized, spanwise-periodic Discrete Roughness Elements (DREs) were applied to the leading edge of a 30-degree swept-wing. The test article was attached vertically to the port wing of a Cessna O-2A aircraft and operated at a chord Reynolds number of 6.5 to 7.5 million. With a polished leading edge, 80% laminar flow was observed corresponding to N-factors greater than 12. Critically spaced DREs were applied at the leading edge to excite the crossflow instability and move transition forward. In this case, calibrated, multi-element hotfilm sensors were used to measure disturbance wall shear stress. The roughness height was varied from 0 to 50 microns both in the positive (bumps) and negative (dimples) sense. Thus, the disturbance amplitude variations were determined as a function of modulated DRE heights. Copyright © 2009 by the American Institute of Aeronautics and Astronautics, Inc.

author list (cited authors)

  • Carpenter, A., Saric, W., & Reed, H.

citation count

  • 23

publication date

  • January 2009