Search

In this study, the three-dimensional flow computations over a realistic aircraft high-lift configuration with a flow-through nacelle with a pylon mounted beneath the main wing are performed using an unstructured mesh method to investigate the influence of the boundary-layer transition on the aerodynamic forces, the capability of a transition prediction method, and the influence of brackets to support the high-lift devices. First, the influence of the boundary-layer transition on the aerodynamic forces is shown by comparison of the computational results with/without the boundary-layer transition. Then a transition prediction method based on the [e.sup.N] method and semi-empirical approaches is evaluated. The capability and areas to be improved are discussed. The influence of brackets to support the high-lift devices on the aerodynamic forces is also discussed. Interference of disturbed wakes by the slat supports to the flows on the main wing and flap is shown.

Flight testing of an unmanned and scaled supersonic experimental airplane NEXST-1 is performed by the Japan Aerospace Exploration Agency to validate computational-fluid-dynamics-based aerodynamic design technology. This is the first attempt to apply the natural laminar flow wing concept to a supersonic vehicle. The concept of the natural laminar flow wing is validated by measuring the surface pressure and the transition locations of the boundary layer. In this paper, the results of the transition measurement are introduced and compared with the numerically predicted results. The transition locations detected experimentally are in good agreement with the predicted locations, and the natural laminar flow effect is confirmed in the aerodynamic design conditions of the supersonic experimental airplane NEXST-1.