What surface quality is necessary on the test-section airfoil and the rest of the wing to provide both good experimental data and to ensure airfoil performance?
Low Reynolds number laminar flows are less sensitive to surface waviness and roughness than high Reynolds number laminar flows. However, low Reynolds number, high Mach number flows are quite sensitive to pressure distribution changes. Therefore, the Apex airfoil will be more sensitive to the accuracy of the airfoil contour than its surface finish. The recommended approach is to specify to what tolerance the finished wing must match the requested airfoil shape. By also specifying that the manufacturer use production sailplane construction techniques, the surface roughness and waviness should be quite adequate. If there is a significant cost/quality trade-off for this construction technique, the manufacturer could pay more attention to the first 60 percent of the upper surface and leave the rest of the airfoil somewhat rougher.
Related Questions
- What surface quality is necessary on the test-section airfoil and the rest of the wing to provide both good experimental data and to ensure airfoil performance?
- How many different airfoils will be tested on the Apex aircraft, and will the test section airfoil be the same as the rest of the wing?
- Are good manufacturing practices necessary if there is a quality control laboratory?
