Aircraft high lift prediction
This study was concerned with the accurate prediction of lift from Computational Fluid Dynamics (CFD) simulations of a realistic airframe configuration. The study was carried out in connection with the AIAA CFD High Lift Prediction Workshop (hiliftpw.larc.nasa.gov), which set out to assess the numerical prediction capability of current-generation CFD technology for landing and take-off high-lift aircraft configurations. The challenge is to capture enough of the airflow phenomena while keeping the cost of the numerical simulation within bounds, with the aim to replace costly wind-tunnel experiments or to understand effects that are impossible to observe directly or measure in the wind tunnel.
The airflow past a realistic aircraft configuration was simulated on a computational grid with 230 million cells. The simulations, which were run several times, at different agles of attack, would take 5 years to complete on a conventional workstation but took only 10 days on the ARC clusters, each simulation running in a distributed mode across 960 cores. The simulations were carried out using the OpenFOAM open-source CFD package.
The agreement with experiment was excellent, as shown in the pictures below. In particular, the plot indicates the model captures the essential physics at a high angle of attack and high lift, which was the focus of the AIAA workshop.