HIGH-LIFT LOW-REYNOLDS-NUMBER AIRFOIL DESIGN

A new high-lift airfoil design philosophy has been developed and exper imentally validated through wind-tunnel tests. A key element of the hi gh-lift design philosophy was to make use of a concave pressure recove ry with aft loading, Three codes for airfoil design and analysis (PROF OIL, the Eppler code, and lSES) were used to design the example S1223 high-lift airfoil for a Reynolds number of 2 x 10(5). In wind-tunnel t ests, the new airfoil yielded a maximum lift coefficient of 3.2. With vortex generators and a 1% chord Gurney nap (used separately), the C-l ,C-max increased to 2.3. The airfoil demonstrates the rather dramatic gains in C-l/max over those airfoils previously used for high-lift low Reynolds number applications.