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AERODYNAMIC DEVICES

Sidepod Ramps

This was inspired by the Renalt R 25 which featured wiglets on the sidepods instead of a side pod that has a curved up shape near its end. The wiglet design is not used as it will create vortices and is hard to manufacture. However this helps to direct the air above the rear wheels to decrease the amount of wheel wake and decreases the drag that will be created by the wheel wake while being easy to manufacture and create no extra drag. This is refined using CFD to find the exact angle which directs the air over the rear wheels without causing a huge separation.

Convex Nose

As the drag can be decreased by decreasing the cross sectional area, we developed a ‘convex nose ’ concept to minimise the cross sectional area while allowing clean air to the side pod ramp. This device is further refined by increasing the undercut angle to reduce cross sectional area. However, the original concept pushed air into the front wheels, creating huge wakes. This is successfully overcome by changing the angle of outwash.

Air Curtains

This device helps to direct clean air across the rear wheels while keeping the dirty air ,generated by the front wheel wake, away from the rear wheels to further increase drag.It also decreases weight and therefore increasing performance.It also decreased the separation before the tip of the sidepods.

Ramp front wing

This was introduced late in the development for the replacement of the high downforce wing. This was inspired by the Jordan 191 which featured similar designs. This device directs the air over the front wheels to minimise the air that will touch the wheel and turn into dirty air, as the wheel will create a vortex inside them during rotation. To maximise the effectiveness of this device, we optimised the angle of attack using CFD.

CFD Simulation

ANSYS Discovery was selected as the primary CFD platform due to its rapid setup workflow and fast solution times, which were well suited to early-stage aerodynamic development and design iteration. The reduced pre-processing and solver configuration time enabled a significantly higher number of simulations to be conducted within the available development window, allowing systematic comparison of multiple aerodynamic concepts and geometries.To ensure the validity and comparability of results, all aerodynamic iterations were evaluated under identical boundary conditions, including inlet velocity, turbulence model, reference area, and solver fidelity. This controlled approach ensured that performance differences observed between designs were attributable solely to geometric changes rather than numerical bias or setup inconsistencies.

Machining Objectives

When manufacturing the final car body, several machining objectives were defined to ensure high aerodynamic and dimensional quality:

Achieve dimensional accuracy within ±0.1 mm relative to the CAD model

Maintain compliance with all competition regulations

Minimise surface roughness to reduce skin-friction drag

Minimal post-machining hand finishing

CNC for the car

The final aerodynamic CAD model was reviewed prior to machining to ensure all minimum feature sizes, fillet radii, and wall thicknesses were compatible with CNC tooling constraints. No go zone defined by the regulations were checked, and additional material allowances were included so the sanding process would not remove too much material and leading to the car breaking the regulations.The CAD model was imported into the QuickCAM Pro Software where toolpaths were generated for the CNC router. Machining strategies were divided into roughing and finishing operations. Tool selection, spindle speed, feed rate, step-over, and depth of cut were optimised to minimise machining forces, thermal distortion, and surface scalloping. The final toolpaths were post-processed into G-code compatible with the CNC machine.The material blank was then securely fixtured to ensure positional accuracy throughout the machining process. Roughing passes were first used to remove the bulk of the material efficiently, followed by finishing passes using smaller diameter tools to achieve the final geometry and surface quality. Multiple machining planes were used to access complex features while maintaining rigidity and minimising deflection.After machining, the component was inspected against the CAD model using callipers and gauges to verify critical dimensions and regulatory compliance. Particular attention was given to nose geometry, wheel clearance regions, and overall body width. Any deviations were recorded and assessed to ensure they remained within acceptable tolerances.A limited amount of hand sanding was carried out to remove minor machining marks and improve surface continuity. This step was minimised to preserve dimensional accuracy while achieving a smooth surface finish, which is critical at low Reynolds numbers where surface roughness can significantly increase skin-friction drag and promote early boundary-layer separation.