Prediction of Aerodynamic Characteristics of Fighter Wings at High Lift.

摘要

A basic viscous/potential flow iterative technique is developed for calculating flow on finite wings up to and beyond the stall. The procedure used is a direct adaptation and extension of successfully validated Analytical Methods, Inc. (AMI) two-dimensional CLMAX separation model to three-dimensional flows. In the potential flow program, the lifting surface is divided into a number of panels with linear and constant vorticity distributions along the chordwise and spanwise directions, respectively. The separation region is modeled in the potential flow analysis using force-free vortex sheets which require an inner iteration to establish their shapes. The program generates a new wake shape using the new separation locations together with the information from the previous iteration and the process is repeated until a convergent solution is obtained. In order to expedite the development process, several simplifying assumptions are made. However, these assumptions do not conflict with the primary objective of the present investigation which is to demonstrate the feasibility of extending the two-dimensional CLMAX separation model to three-dimensional flows. The separation flow model and the developed computer program are validated by comparing the results with wind tunnel test data for some simple cases.