About Campus Tirol Motorsport
Campus Tirol Motorsport is the place where passionate students from Tyrolean universities work on the development of an innovative electric racing car. What’s our motivation? Our love of motorsport and our unbeatable team spirit. Teamwork is not just a buzzword for us, but the secret of our success. We firmly believe that close collaboration between students, university and company is the key to realizing our dreams. This dedication characterizes everything: from the design of our racing car to the promotion of innovation in the motorsport world. Our motto is Design, Build, Race, Repeat!
For the Campus Tirol motorsport team’s 2025 electric Formula Student race car, effective thermal management of the drivetrain inverter was crucial for optimal performance. This case study details the engineering approach and analysis conducted using the HeatSinkCalculator to develop a robust heatsink and fan solution, ensuring MOSFET junction temperatures remained below 175°C with a 270W heat dissipation target
Heatsink Selection
The team evaluated various commercially available copper and aluminum skived heatsinks using the HeatSinkCalculator, considering specific operating conditions: a heat source area of 39x55mm, ambient temperature of 40°C, altitude of 700m, 270W power losses, and a flow rate of 0.0912m³/s. Due to significant differences in airflow rate and heat source area compared to heat sink datasheet test conditions, the manufacturer provided thermal resistances could not be used.
Comparative analysis revealed that copper heatsinks offered limited thermal advantages relative to their increased mass. Consequently, an aluminum heatsink was selected.
Cooling layout
The arrangement of the inverters in the box makes serial cooling of two inverters on one side the simplest solution. However, this means the downstream inverter receives air that has already been heated by the front motor controllers. The upstream and downstream heat sinks were analyzed individually.
For the upstream heat sink with serial cooling, the pressure of the fan is halved since the fan has to push air over both heatsinks. For the downstream heat sink, the ambient air temperature is increased by the amount that the air heats up as it passes over the first heat sink. This is calculated as: dT = Q / (cpAir * flowrate * air density). The downstream MOSFET temperature in this configuration was significantly higher than the 175°C limit.
A parallel layout shown in figure 1 was evaluated. The fan flow rate was halved and pressure reduced by 30% to account for ducting restrictions.
Figure 1. Fan cooled heat sinks with a parallel flow configuration
This layout met the junction temperature requirements while still allowing for a reasonably sized fan. See analysis results for this configuration in figure 2.
Figure 2. Thermal analysis results for the down stream heat sink and MOSET for the simple parallel flow configuration
Heatsink Validation
To validate the design, a power supply was used to induce current through the MOSFET body diodes, generating precise power losses.
The measured and calculated heat sink thermal resistance values showed strong correlation across the power loss range, despite neglecting the exact heat generation distribution. The close agreement between calculated and measured temperature values confirms the reliability of the design and ensures sufficient cooling performance for the application.
We used the heatsink calculator to both select a heatsink for our motor controller and design the heatsinks for the motors for our electric Formula Student race car. In both cases, the heatsink calculator enabled us to find solutions that best fit our requirements quickly, especially when compared to previous methods like CFD. Additionally, we have been able to accurately reproduce the calculated results in testing, giving us high confidence in the results produced by the heatsink calculator.
Lukas Baldo, Tech Lead for Campus Tirol Motorsport
