15/06/2026
30 Million Cells Behind One Winglet
Our previous post was about the solver that calculates the airflow. Today, however, we are taking a step back in the CFD pipeline to look at an earlier stage of the process. After all, there is no reliable solution without a proper mesh.
Once we define the volume of air surrounding the aircraft, we divide it into millions of smaller elements called cells. Each cell stores information about the flow, so having enough of them, in the right places, is crucial.
We are not cutting corners here either. Our mesh contains around 30 million cells. You may need to zoom in on the images to see some of them properly.
We also use a custom meshing workflow. On the winglet surface, the largest cells are below 5 mm, while the smallest are around 1 mm. The rest of the wing is not much coarser, with cell sizes kept below 1 cm across the entire wing surface.
But surface resolution is only part of the story. We also need to capture the boundary layer, the thin region of airflow directly next to the aircraft surface.
Our first boundary-layer cell is only 0.01 mm thick, followed by more than 20 carefully growing layers before reaching the main flow. This allows the solver to capture the near-wall airflow and turbulence with a high level of detail.
We will spare you the full explanation of dimensionless wall distance, better known as y+, for now. The simple version is that our boundary-layer resolution is closer to research-grade CFD than to a typical early-stage engineering simulation.
Stay tuned as we continue exploring the different parts of our winglet development process.
