FSAE Fuel System
September 2019 - May 2020
The objective of this project was to design and manufacture the fuel system for our FSAE car. The purpose of this system is to store the fuel and ensure it is efficiently delivered to the engine. To this end, the system consists mainly of a fuel tank for storage, a filler neck to refill the supply, a fuel pump to pump fuel from the tank to the injector block, and appropriate tubing to serve as connections between system elements.
Design Objectives
I undertook the redesign of the system with the objective of better accomplishing the system goals outlined above, devising solutions to outstanding packaging problems associated with the system in past years, and improving on the team goals of weight reduction and increased vehicle performance.
Past years' problems included dangerous proximity of fuel lines to the engine block, a structurally unstable filler neck design, insecure mounting of the fuel tank to the chassis, and the presence of an undesirable air bubble at the top of the fuel tank.
Design
Major redesigns I made to the system were:
Mounting the fuel pump on the back of the fuel tank itself to reduce the amount of tubing required from the tank to the pump entry. As a result, this area of tubing would be better shielded from the high temperatures of the engine block
Move the location of the filler neck to be welded onto the top of the fuel tank, as opposed to the side of the tank. This allowed more space between the filler neck and the engine block, and also served to eliminated the air bubble that was previously present at the top of the fuel tank.
Manufacturing the filler neck from aluminum as opposed to rubber to improve structural integrity
Removing a small pan-like extrusion from tank base in order to save weight from extra fuel
Filling tank with KSR anti-slosh fuel tank foam to prevent fuel pickup line from running dry due to fuel sloshing caused by extreme cornering
Designing aluminum tabs for tank mounting
Rubber grommets used for the mounting to prevent loading of the fuel tank if the chassis was subject to torsional loading
SolidWorks Model of Fuel System
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Testing of Anti-Slosh Fuel Tank Foam
I made a prototype of the fuel tank from laser-cut acrylic sheets to examine the effect of fuel tank foam on the reduction of fuel sloshing. The results are shown here. As the foam was able to reduce sloshing and maintain presence of fuel at pickup point (at the back of the tank), it was used in the final design of the car.
Manufacture
The fuel tank a was laser-cut from 14 gauge aluminum, and welded together. We outsourced the laser cutting  to a local company, and the welding was done by other members of my team. I machined the fuel tank bungs and the filler neck in the machine shop at Brown, and custom-made the fuel pump mount at the back of the tank.
Manufactured Fuel System
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