To recover the aerodynamic performance that is normally lost around and behind the tires, and to manage the front wing's wake before it reaches the rear wing. New scope introduced on CR26E.
Three concepts are in development. Downforce-producing side aero (DoPSA) places airfoil stacks alongside the car to make additional downforce while blocking the rear tires. A rear tire wall is a flat plate positioned to reduce rear tire drag. A front wing upwash element is an airfoil in lift-producing configuration intended to lift the front wing wake clear of downstream components. On earlier cars the same physical space was occupied by the sidepods, which is why the tracker lists Sidepod and the water-to-air and oil-to-air sidepods under this subsystem for CR22 through CR26I.
Do not compromise the rest of the package to add side aero. Because turbulent air off side devices demonstrably reduces rear wing downforce and raises its drag, every concept starts with an inner endplate and is judged on whole-car numbers, not on its own load. On CR26E the undertray is the mounting structure for most side aero, so undertray geometry, not free space, sets what is possible. 1. 2D sweeps to find airfoil placement within a stack. 2. 3D placement of the stack itself, judged on whole-car downforce, drag, efficiency and center of pressure. 3. Compare against the current combined-run baseline rather than against an isolated case. 4. Accept only where the gain is outside the CFD margin of error.
- Keep CLA at or below 4.207 and CDA at or below 1.3, landing inside the optimal efficiency target window. - Add downforce without reducing rear wing performance. - Reduce rear tire drag. - Determine whether an upwash element is worth its mass.
- DoPSA proximity to the front tire has been the primary packaging problem. Three-element side aero raised downforce from 277.27 N to 289.14 N but raised drag from 106.23 N to 118.12 N, dropping efficiency from 2.610 to 2.448. - Rear tire wall results are inside the CFD margin of error. Tall and short walls both showed slight gains on the CR25 baseline, but adding a short wall to the Iter017 floor showed a slight loss. No clear benefit yet. - The upwash element raised rear wing downforce from 109.84 N to 120.64 N but cut floor/body downforce from 52.39 N to 37.39 N, for a net efficiency loss from 2.245 to 2.138. Promising but not settled.
ANSYS Fluent combined half-car and full-car runs, with pressure and velocity LIC slices used to read the interaction between devices. Iteration tracking spreadsheet shared with the rest of the aerodynamic package.