Composite sandwich structures are being used in the automotive and aerospace industries at an increasing rate due to their high strength and stiffness per unit weight.  Many teams in the world’s largest engineering competition for students, Formula Student, have embraced these types of structures and are using them in their chassis with the intent of increasing the torsional stiffness per unit weight.   The Formula Student team at Karlstad University, Clear River Racing, has since 2017 successfully built three carbon fiber based sandwich structure chassis. A big challenge when designing this type of chassis is the lack of strategy regarding torsional stiffness simulations. Thus, the goal of this thesis project was to provide the organization with a set of accurate yet relatively simple methods of modelling and simulating the torsional stiffness of the chassis.   The first step in achieving the goal of the thesis was the implementation of simplifications to the material model. These simplifications were mainly targeted towards the aluminum honeycomb core. In order to cut computational times and reduce complexity, a continuum model with orthotropic material properties was used instead of the intricate cellular structure of the core. To validate the accuracy of this simplification, the in-plane elastic modulus of the core was simulated in the finite element software Abaqus. The stiffness obtained through simulations was 0.44 % larger than the theoretical value. The conclusion was therefore made that the orthotropic continuum model was an accurate and effective representation of the core.   Furthermore, simplifications regarding the adhesive film in the core-carbon fiber interfaces were made by using constraints in Abaqus instead of modelling the adhesive films as individual parts. To validate this simplification and the overall material model for the sandwich structure, a three-point bend test was simulated in Abaqus and conducted physically. The stiffness for the sandwich panel obtained through physical testing was 2.4 % larger than the simulated stiffness. The conclusion was made that the simplifications in the material modelling did not affect the accuracy in a significant way.   Finally, the torsional stiffness of the 2020 CFRP chassis was found to be 12409.75 Nm/degree.   In addition to evaluating previously mentioned simplifications, this thesis also serves as a comprehensive guide on how the modelling of the chassis and how the three-point bend test can take place in regards to boundary conditions, coordinate system assignments and layup definitions.

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This thesis investigates an aerodynamic optimization of front lower wishbones on a FormulaStudent car using CFD simulations and windtunnel testing. The aim of the study is to de-termine weather a geometric optimization of wishbones is feasable and could enhance theaerodynamic performance of the vehicle.Siemens Star-CCM+ is utilized for the CFD simulations with focus on iterative design im-provments to optimize the initial generic airfoil shape. The CFD model is based on the modelprovided by KTH Formula Student. The model was also developed further in the initial stagesof the study. Turbulance transition model was investigated as well as the turbulance model toaccurately capture the near wall flow dynamics.In order to validate the results from the CFD model a set of windtunnel tests where doneinvolving a 13 scale model of the vehicle at various yaw angles.Some key findings from the analysis indicate that significant changes in the aerodynamicalcharacteristics can be made by making relatively small changes to the geometry of the vehicle.An increase of 2,1% was achieved which closely correlate to the accuired data which indic-ated a 2,2% increase.The optimization process highlighted the importance of developing CFD optimization tech-niques as they can make large contributions to the aerodynamic characteristics of vehicles.This can be used in order to increase the performance of of vehicles in motorsport or reducedrag in everyday vehicles to reduce the energy consumtion.

Formula Student is Europe’s most established engineering competition, with teamsall over the world. Practical problem solving in combination with applyingacademic knowledge, give students the opportunity to explore their field of study inan exciting and meaningful way. Aerodynamic development of race cars have seen significant results in competitionsince its introduction in the 1960s. Initial designs were adaptations of aerospaceconcepts for ground vehicles. Development relied solely on track- and wind tunneltesting but despite their rudimentary designs, significant performance increaseswere made. The purpose of aerodynamic development of race cars is to balance thecar, getting it to behave as desired. As a consequence of the forces generated, thevehicle corners faster at the cost of acceleration and top speed. With more powerfulcomputers, earlier unsolvable equations started to get numerically solved andcomputational fluid dynamics was born. CFD introduced the possibility for rapiditeration and exploration of more intricate designs. This report will solely utilizeCFD as a simulation tool, recognising its limitations in accuracy and real worldcorrelation. The aim of this study is to increase downforce on the front wing, whilst beingcautious of downstream impact. The goal set by the team is an adjustable frontwing that generates as much downforce as possible, whilst allowing for adjustmentsto shift the center of pressure by promoting more air to the side-structure. Toachieve this, an iterative design process based on literature is the chosen method.Continuous cross evaluations with other parts of the design team is of the highestimportance to avoid poor interaction between aerodynamic devices. The (negative) lift coefficient was increased from 4.7 to 5.7 for the entire vehicle, byonly improving the front wing. This was very satisfactory as increases upstreamoften lead do degraded performance downstream. An increased lift coefficient ofover 20%, with improvements to front wheel drag and similar side-structureperformance, demonstrate the quality and effectiveness of the design.

This thesis deals with the design of steering holder for a race car in the category Formula Student using topology optimisation and analysis of this design. The objective of this thesis is gaining knowledge about topology optimisation and application of this knowledge to the design of a replacement of the steering gearbox and its holder.

This thesis deals with the design and production of wheel control holders for the right front wheel of the formula Dragon 4 of TU Brno Racing team. In the theoretical part, the Formula Student competition is described, including the steering holders themselves and description of their function and location. Later the analysis of aluminium and its alloy was made, including description of the CERTAL material of which the holders were made. The practical part includes the design of prototype holders in the Autodesk Inventor CAD software, the design and application of machining strategies in the PowerMILL CAM software. Further, the practical part includes production on milling machines at the MCV 754 QUICK and DECKEL MAHO DMU 50 machining centre. At the end, the dimensional analysis of the part is performed, manufactured holders were compared to the CAD model of the given components and the technical and economical evaluation of the production was made.

Diploma thesis deals with a design and manufacture of oil cooler by technology Selective Laser Melting for Formula Student. The main goal of the design is to ensure optimal oil circuit cooling at a minimal mass. The design of manufactured oil cooler is based on a plate heat exchanger concept with optimized intakes by CFD simulations and heat exchange body with fins of thickness 0.17 mm. An analytical model was created. SLM process parameters were optimized for a thin walls printing, Subsequently, a fabrication of testing parts was finished for measuring pressure drops and performances of micro heat exchangers. Results were used for an accuracy improvement of the analytical model and for consequent optimization of heat exchange surface. Afterwards optimization was executed for inlets and outlets by using flow simulations. A prototype was built and verified on a test stand. Performance of the designed oil cooler is 4.5 kW for race mode, where temperature drop of oil circuit is 22 °C. The lightweight design weighs 320 g, which reduces more than 47 % of a current oil-air cooler weight. Furthermore, a centre of gravity is decreased by designed placement of the cooler.

Master’s thesis focused on design and construction of front uprights for Formula Student racing car. Topology optimization and FEM analysis will be used to design the uprights with higher stiffness and minimal weight difference compared to the last model. In the FEM analysis loads will be applied from wheel side and from suspension side. Design of the upright then will be compared to the previous designs especially to safety factor, weight and cost.

The topic of this master´s thesis is the design of adaptive damping algorithm for the prototype magnetorheological dampers, which are used for Formula Student vehicle. The prime output is the development and optimization of the control algorithm which included usage of the MBS software and real data from race track. Temperature compensation to supress the effect of dynamic viscosity of magnetorheological fluid due to the increase in operating temperature and testing of the vertical dynamic of the car on 4 - post test rig was realized as well. The main goal was to obtain better control of the car in transient situations and increase usability of tires via changes in damping based on actual conditions and status of the vehicle.

The main goal of this thesis is to obtain lateral parameters of the Magic Formula tire model of a tire commonly used in Formula Student competition. Both the author and the supervisor of the thesis know the tire name and its specification, but the research company that did the tire testing and provided me with the date prohibits sharing this of data publicly, so the tire designation is not mentioned in this thesis. The first chapter covers main theoretical facts related to a tire, briefly describes some of the tire models and shows possibilities how to determine tire characteristics that are used in a tire model. The thesis describes how to process raw tire data measured during a laboratory experiment using scripts created in Matlab software. The inputs variables are slip angle, lateral force, normal force and inclination angle. Raw data are splitted into parts, main coefficients of the Magic formula model (B, C, D, E, Sh, Sv) are calculated and subsequently the lateral parameters are obtained using least square method to fit parameters into the measured data. The works gives two main outcomes. The first output is a set of Matlab scripts that can be used to determine lateral parameters of any tire that has the same input data format as presented. A TIR file of the Formula Student tire in case of lateral slip is the second result of the work. This can be used for vehicle dynamics simulation of Formula Student racing car. The thesis also offers a comparison between parameters, which I calculated, and those gained thanks to Optimum Tire software by Calspan research company. Additionally the work shows the effect of load and inclination angle on lateral force.