Design of a Formula SAE Aerodynamic Undertray

Willoughby, Ashley (2013). Design of a Formula SAE Aerodynamic Undertray Honours Thesis, School of Engineering, The University of Queensland.

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Author Willoughby, Ashley
Thesis Title Design of a Formula SAE Aerodynamic Undertray
School, Centre or Institute School of Engineering
Institution The University of Queensland
Publication date 2013
Thesis type Honours Thesis
Supervisor Ingo Jahn
Total pages 183
Language eng
Subjects 0913 Mechanical Engineering
Formatted abstract
This thesis investigates the design and optimisation of a Formula SAE aerodynamic undertray in ground effect suitable for the UQ Racing 2013 vehicle (UQR-13) in order to maximise the aerodynamic lift-drag ratio. The study has been conducted using ANSYS Fluent computational fluid dynamics software and Solidworks software for finite element analysis & computer aided drawing aspects. The scope of this research includes fluid dynamics optimisation, structural design of the optimised design and the development of a manufacturing procedure.

UQ Racing is the University of Queensland¡¯s Formula SAE team. Formula SAE is an international design competition organised by the Society of Automotive Engineers (SAE) in which University teams are required to design, build and race a formula style racing vehicle. UQ Racing is in the process of developing an aerodynamic undertray that will integrate to the current geometry of the vehicle so that they are able to improve the vehicle performance.

The research methodology consists of optimising a 2D profile to obtain a maximum lift/drag ratio for low structural weight. It was found that low moderately low inlet angles (20¢ª) and low diffuser angles (5¢ª) were most desirable for lift/drag performance. Diffuser exit heights and overall undertray length have exploited all available space that was allowed by the vehicle geometry to obtain maximum downforce. The ride height was found to be optimal at moderate ride heights (110mm) however due to geometric restrictions of the UQR-13, this was restricted to a height of 30mm. This 2D design was extended into the 3rd domain for further analysis and refinement. The final undertray configuration concluded that for further improved performance, endplates should be incorporated along the inlet and exit sections and turning vanes should be incorporated into the throat-diffuser section. This design was analysed under different operating conditions such as yaw, roll, pitch and speed. The completed design achieves a theoretical total downforce of 51.6N and 10.21N of drag.

Finite element methods and materials selection processes were used to ensure minimal structural compliance, sufficient strength under worst case scenario loading and minimal structural weight. A total system weight (interfaces included) of 10.8kg has been achieved.

A set of guidelines to designing an aerodynamic undertray has been developed to assist the reader in understanding the design elements that should be targeted and those that should be avoided. This study concludes with further recommendations and suggested changes that will potentially lead to performance improvements as far as 500%.
Keyword Formula SAE

Document type: Thesis
Collection: UQ Theses (non-RHD) - UQ staff and students only
Citation counts: Google Scholar Search Google Scholar
Created: Thu, 10 Dec 2015, 13:43:15 EST by Asma Asrar Qureshi on behalf of Scholarly Communication and Digitisation Service