Automatic Transition Prediction in a Hybrid Flow Solver, Part 2: Practical Application

Abstract

This article is the second of two companion papers which document the concept and the application of a coupled computational fluid dynamics system which was designed to incorporate the prediction of laminar�turbulent transition into a hybrid Reynolds-averaged Navier�Stokes solver. Whereas the first part deals with the description of the transition prediction methodology and the sensitivities of the coupled system, the second part documents its practical application. The complete coupled system consists of the Reynolds-averaged Navier�Stokes code, a laminar boundary-layer code, and a fully automated local, linear stability code. The system predicts and applies transition locations due to Tollmien�Schlichting and crossflow instabilities using the eN method based on the two-N-factor approach. The coupled system was designed to be applied to three-dimensional aircraft configurations which are of industrial relevance. The application of the coupled system to a wing�body configuration with a three-element wing consisting of slat, main wing, and flap is described and documented in this paper. The prediction of the laminar� turbulent transition lines was done in a fully automatic manner. It is shown that complex aircraft configurations can be handled without a priori knowledge of the transition characteristics of the specific flow problem.