Prediction of Dynamic Stall Characteristics Using Advanced Non-Linear Panel Methods.

摘要

A surface singularity panel method was extended for modeling the dynamic interaction between a separated wake and a surface undergoing an unsteady motion. The method combines the capabilities of an unsteady, time-stepping code and a technique for modeling extensive separation using free vortex sheets. Routines were developed for treating the dynamic interaction between the separated wake and the solid boundary in an environment where the separation point is moving with time. The behavior of these routines is being examined in a parallel effort using a two-dimensional pilot version of the three-dimensional pilot version of the three-dimensional code. This allows refinements in the procedures to be quickly developed and tested prior to installation into the main code. The extended code was coupled with an unsteady integral boundary layer method to examine the prediction of dynamic stall characteristics. The boundary layer code is accessed during the time-step cycle and provides the separation locations as well as the boundary layer displacement effect: the latter is modelled in the potential flow code using the source transpiration technique. The preliminary results include basic unsteady test cases for both the potential flow and boundary layer routines.