Automatic Transition Prediction for Three-Dimensional Aircraft Configurations using the DLR TAU Code

A Reynolds-averaged Navier-Stokes solver, a laminar boundary-layer code and a fully automated local, linear stability code for the prediction of Tollmien-Schlichting and cross flow instabilities were coupled for the automatic prediction of laminar-turbulent transition on general aircraft configurations during the ongoing flow computation. The procedure is applied to different three-dimensional wing-body configurations and the sensitivity of the coupled system to a variety of coupling parameters is investigated

Comparison of a Local Correlation-Based Transition Transport Model with an eN-Method for Transition Prediction

The γ -Re θt model, a parallelizable, correlation-based, transition transport model was implemented into the DLR TAU code. Its capability to predict transition has been investigated at one-element airfoils, such as Somers NLF(1)-0416 airfoil and a transonic airfoil of Messerschmidt-Bölkow-Blohm. The influence of relevant input parameters is discussed in terms of predicted transition locations and skin friction coefficient distributions. The standard transition prediction approach in the DLR TAU code is based on the eN-method, a non-local, streamline based approach. Coupling TAU with a boundary layer and stability analysis code enables transition prediction within the RANS solver. The results of both transition prediction methods are compared to each other and the advantages and short-comings of either model are pointed out

A Conceptual Study of a Transonic NLF Transport Aircraft with Forward Swept Wings

DLR’s concept for a natural laminar flow transonic transport aircraft with forward swept wings is presented. Giving an overview on the aircraft’s configurational layout first, the focus is on the multidisciplinary design of NLF wing and its aerodynamic performance. Results from high-fidelity coupled aero-structural simulations show that a significant extent of laminar flow is achievable. Torsional divergence of the wing is successfully suppressed by aeroelastic tailoring. The impact of elastic wing deformation on boundary layer stability and NLF performance is studied. Finally, results of the aircraft’s cruise performance and expected fuel savings are provided and compared to results from preliminary design