Sixth Drag Prediction Workshop Results Using FUN3D with k-kL-MEAH2015 Turbulence Model.

Area of Science:

• Computational Fluid Dynamics (CFD)
• Aerospace Engineering
• Turbulence Modeling

Background:

• The Common Research Model (CRM) wing/body configuration is a standard benchmark in aerodynamic research.
• Accurate prediction of turbulent flow is essential for aircraft design and performance optimization.

Purpose of the Study:

• To investigate the performance of the k-kL-MEAH2015 turbulence model for the CRM configuration.
• To evaluate the impact of a nonlinear quadratic constitutive relation variant on aerodynamic predictions.
• To assess the influence of grid resolution on simulation accuracy.

Main Methods:

• Implementation of the k-kL-MEAH2015 turbulence model in the FUN3D CFD code.
• Utilizing workshop-provided grids and performing uniform grid refinement studies.
• Comparison of results with and without a reconstruction limiter.
• Analysis of a nonlinear quadratic constitutive relation variant against the linear eddy-viscosity model.

Main Results:

• A significant variation in results was observed on medium grids without a reconstruction limiter, highlighting their inadequacy for experimental comparison.
• Grid refinement reduced the observed variations, indicating its importance for accurate simulations.
• The nonlinear quadratic constitutive relation variant showed decreased lift and drag compared to the linear model, with this difference remaining consistent across grid refinements.
• The k-kL-MEAH2015 model successfully replicated wing-root junction flow behavior observed in wind-tunnel experiments.

Conclusions:

• The k-kL-MEAH2015 turbulence model demonstrates good agreement with experimental data for wing-root flow.
• Careful consideration of grid resolution is crucial for obtaining reliable aerodynamic predictions.
• The nonlinear variant offers potential for improved lift and drag prediction accuracy.