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This project was done as part of my first-year design and computing module. The project aimed to design an aerofoil for use on a race car. Therefore, the aerofoil is required to maximise downforce whilst minimising drag to achieve faster speeds and consequently better lap times. Additionally, the aerofoil is expected to be attached to the race through the use of two pylons and the whole assembly is required to fit within a e 1050mm (span) x 500mm (chord) x 500mm (height) box. To assess the performance of the rear wing a Python simulator called "lapsim.py" was used, which took data such as the drag area coefficient (CDA) and the lift area coefficient (CLA) to estimate a lap time.
Identifying the target lap time
Since a Python code already existed to calculate lap times from the lift and drag coefficients, I started by creating an array of the lap times obtained through different combinations of the two coefficients. Then by using the optimizing function from Scipy.optimize I was able to identify that the ideal lap time of 65.5 seconds corresponded to CDA = 0.067 and CLA = 0.523 as highlighted in the figure to the right.
Generating an optimised aerofoil shape
After having identified a target lap time and the corresponding CDA and CLA I proceeded to design the aerofoil. To do this I started by creating an arbitrary aerofoil using two Bezier curves, each with 4 control points as shown below. I then fixed all the points except point y_q2 indicated by a green dot. This allows me to focus on optimising the aerofoil performance by only varying the position of one control point as opposed to six. I then proceeded to create an array containing a variety of positions for point y_q2 as well as a variety of attack angles. Then using the Python simulator "airfoilsim.py" I was able to identify the lift and drag coefficients CL and CD corresponding to the varying aerofoil geometries and attack angles. Then by using the optimise function again, I was able to identify the optimal parameters.
Rear wing design in Solidworks
Having identified the ideal aerofoil shape I proceeded to model the rear wing in solid works. After creating the model I decided to use Solidworks Flow Simulations to simulate the effect of airflow over the wing and calculate the relevant values for CLA and CDA. Using these along with the "lapsim" simulator the predicted lap time was 70.5 seconds. Whilst this indicates a good performance it is still relatively far from the ideal lap time of 65.5 seconds. Therefore I started iterating on the wing design by considering the use of multiple aerofoils. Whilst this allowed me to improve the lap times it was still ~3 seconds slower than the optimal. Therefore I also considered modifying the attack angle. After several more iterations, I arrived at a lap time of 65.8s which I deemed to be sufficient enough to consider the wing design optimised.
Final rear wing design
After having tested the different aerofoil configurations and layouts the best-performing design was further developed to meet the required saftey and design requirements. The resulting model is shown below.
For more information or any queries regarding this project please email me at vadakumcherydylan@gmail.com
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