by Brandon Woltz (Chassis Team Head)
The University of Windsor Formula SAE team made a number of great strides forward in the design of their chassis and induction systems for the 2007 Formula competition. With the help of ANSYS Inc. software, the Formula team was able introduce composite materials into their design – a first in Windsor’s history. Sandwich panels were integrated into the Chro-moly space frame, allowing the team to drastically increase the torsional rigidity of chassis while also lowering the frames weight. The combination of the panels and elimination of the rear box in the engine compartment allowed for a reduction in weight of 15% over the 2006 chassis and increase in overall torsional rigidity of 200%. These improvements were made possible through extensive FEA analysis in ANSYS. Load paths, VonMises stress, Tsai-Wu and DOF solutions were analyzed using ANSYS software and benchmarked against previous team’s chassis’ to validate the design. ANSYS software was also used in the validation of suspension control arms and hubs. The 2008 Formula team plans to further optimize our designs through FEA in ANSYS. Without the support of ANSYS Inc., these improvements would not have been realized.
Deflection of front of chassis.
Def election of rear of chassis.
In addition to the use of ANSYS Inc.'s CAE capabilities for structural validation in the chassis, developmental designs of the engine induction system could also be justified using Fluent. The CFD based software provides a 3-dimensional fluid analysis of the induction system. Coupled with 1-dimensional engine software, optimization of the designs can be made accordingly. In particular, Fluent was heavily used in the design and integration of a restrictor plate (sanctioned by FSAE rules). Because this rule creates a limiting factor on the engine output, maximization of fluid characteristics is crucial in providing desired engine performance.
A first iteration of the restrictor illustrates flow separation occurring downstream of the throat. With the help of Fluent, the diverging section of the restrictor can be optimized such that flow separation does not occur. Similarly, flow characteristics such as flowrate, velocity, Mach number and energy losses can all be accounted for in the analysis.
Coupling the capabilities of Fluent CFD into the design validation stages of the induction system offered a beneficial solution in optimizing the overall engine output and performance characteristics.
Recirculation at restrictor - Magnitude of Velocity path plot.
Velocity contours downstream from throat of restrictor.