TeamKART: Official Formula Student Team of IIT KGP

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TeamKART is a group of students from Indian Institute of Technology Kharagpur who like to explore the practical side of automotive engineering.This is officially a sponsored research project under the Sponsored Research and Industrial Consultancy Cell (SRIC) and the Department of Mechanical Engineering, IIT Kharagpur. I contributed to the project K5 which has been one of the most successful endeavours of the team so far.

As a member of the Powertrain subsystem, I collaborated in the design of the following components for the vehicle:

• 3D printed Intake manifold
  FSAE rules dictate that the intake system should consist of a restrictor of 20 mm dia. in order to limit power output of the engine. Due to the presence of a restrictor, a significant pressure drop is generated and this drop is recovered with a diffuser, after which the mass of air enters into the plenum, which serves as a reservoir of air, almost at atmospheric pressure. Following the plenum, the last component is the runner whose length is optimised to generate max engine power at a given RPM. We use KTM DUKE 390 which is a 4 stroke single cylinder engine. The entire design is initially simulated on Ricardo WAVE and based on the results obtained, the steady-state Ansys Fluent Analysis is performed. This process is iterated until an acceptable engine performance and fluid behavior is obtained.


• Fuel Tank
  Our fuel tank is made using industrial grade Aluminium. This ensures significant weight reduction compared to using steel. The key feature of the design is to ensure minimum pressure drop on the fuel pump so as to prevent any disturbance to the engine's fuel supply. We introduce baffles to serve this purpose. Lastly, the mounting of the fuel tank should be such that it can sustain the longitudinal and lateral accelerations that the vehicle can achieve, keeping the flexibility in mind. The total capacity of the fuel tank to sustain the Endurance Event in FSAE competitions is estimated by simulations using Optimum Lap developed by OptimumG.


• Drivetrain arrangement
  The drivetrain package is composed of a chain-sprocket drive, Drexler Limited Slip Differential and driveshafts for the rear wheels. We use Optimum Lap developed by OptimumG as a simulation tool to calculate the optimum Final Drive Ratio (FDR) to achieve the desired lap times in the dynamic events in FSAE competitions, using the engine and vehicle's parameters. After calculating the FDR, we design the sprocket and perform steady-state static and fatigue analysis on the same to ensure its reliabilty. The driveshafts are designed considering the required lengths, diameters of the wheel hubs and CV joints. It is ensured that the 2 driveshafts have equal torsional stiffness.


• Downflow Radiator
  We designed the radiator considering the heat required to be dissipated and packaging constraints. Our primary goal was to calculate the required convective area satisfying the constraints. Using the LMTD method to perform the calculations, we obtained the required dimensions and then got it manufactured. The airflow was enhanced using 2 axial fans selected to ensure the required mass flow rate of air for efficient heat rejection.

With respect to the team's eectric vehicle design, I contributed to the following:

• Motor selection and transmission system
  We shortlisted a variety of motors based on cost, availablity in India, controllability, etc. Following this, we performed multiple simulations on Optimum Lap to select the motor to achieve the required lap time. Planetary gear arrangement coupled with chain-sprocket drive was the transmission system finalized to satisfy the torque requirements of the vehicle. Steady-state static and fatigue analysis were performed to finalize the design and material selection.


• Cooling system
  The selected motor was air-cooled by design. We performed thermal analysis to ensure its cooling performance. The motor controller was cooled by forced convection using heat sinks and axial fans. All the simulations were performed on Ansys ICEPAK.