Grid generation by elliptic partial differential equations for a tri-element Augmentor-Wing airfoil

摘要

The Augmentor-Wing is a promising new development in airfoils for transport aircraft. It consists of a main airfoil with a slotted trailing-edge for blowing, and two smaller airfoils shrouding the blowing jet. Impressive short-takeoff-and-landing (STOL) results have been observed in flight, and both wind-tunnel tests and computational studies predict remarkably low drag in the cruise configuration.Two separate efforts to numerically simulate the flow about this airfoil in the cruise configuration are being pursued. One uses an unsteady viscous flow-solver, and the other a transonic full-potential approach. The inviscid full-potential approach will be used as a preliminary design tool to test a variety of configurations because of its relatively high speed; the viscous flow-solver will be used as a design verification tool to supplement experimental testing. The grid-generation program GRAPE has been adapted to satisfy the significantly different needs of these two studies. The flow field is divided into zones, and continuity of grid lines and their slopes across zonal boundaries is assured. In addition, grid cell size and skewness at the body boundaries is controlled. This new application of grid generation by elliptic partial differential equations for this “real-world,” multielement problem is described.