文档介绍：724 J. AIRCRAFT VOL. 25, NO. 8
Low-Reynolds-Number Airfoil Design for the
. Daedalus Prototype: A Case Study
Mark Drela*
Massachusetts Institute of Technology, Cambridge, Massachusetts
The rationale used for the aerodynamic wing design of the prototype long-range human-powered aircraft
Light Eagle is presented. Three different airfoils, designed for chord Reynolds numbers of 500,000,375,000, and
250,000 were used across the wingspan. The airfoil design rationale centered on minimizing the losses in the
transitional separation bubbles typically occurring on airfoils at Reynolds numbers of less than 1 million. Struc-
tural and manufacturing constraints were also a consideration in the airfoil design, although to a lesser extent.
Airfoil performance prediction during the design process was done entirely through numerical simulation. The
numerical model employs the Enler equations to represent the inviscid flow, and an integral boundary-layer for-
mulation to represent the viscous flow. Strong viscous-inviscid coupling and an amplification transition criterion
included in the overall equation system permit calculation of transitional separation bubbles and their associated
losses. Flow visualization tests performed on the Light Eagle at various lift coefficients in towed flight revealed
transition occumng very near the intended posi