Application of a Hybrid Navier-Stokes Solver with Automatic Transition Prediction

Abstract

A hybrid Reynolds-averaged Navier-Stokes solver, a laminar boundary layer code and a fully automated local, linear stability code were coupled in order to predict the laminar-turbulent transition due to Tollmien-Schlichting and cross flow instabilities using the e N-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 system to a two-dimensional two-element airfoil configuration and a threedimensional generic full aircraft configuration is described and documented in this paper. The prediction of the laminar-turbulent transition lines was done in a fully automatic manner. It will be shown that complex aircraft configurations can be handled without a priori knowledge of the transition characteristics of the specific flow problem. The computational results are partially compared to experimental data.

Conceptual Wing Design Methodology for Aircraft with Hybrid Laminar Flow Control

“…LILO uses a frequency estimator for the detection of the relevant regions of amplified disturbances for TSI and a wave length estimator for CFI, which allows a wider application range compared with the classical e N -database methods. 25 As an example, the amplification exponents (N-factors) for Tollmien-Schlichting (N T S ) and crossflow (N CF ) instabilities calculated with LILO for an HLFC airfoil are shown in Fig. 2(a) and 2(b), respectively.…”

Hybrid, numerical solutions, for three‐dimensional, compressible Navier‐Stokes layer

“…Therefore they are accurate, rapid convergent and very useful for the computation of the subsonic or supersonic flow over FCs, and for the performing of the viscous global optimal design of the FC's shape. For subsonic flow a promising TAU code was developed by DLR, as in [3].…”