Keeping it Cool: AFR’s Cooling System Upgrades for ’20

by Dillon Smith

The Engine Development team at Anteater Formula Racing is hard at work on developing cooling upgrades for this year’s car.

The Formula SAE competition demands the best from every system, but one of the biggest challenges is keeping the engine cool during the Endurance event.

This year, Wraith suffered from a seized engine during Endurance at Lincoln. This was due in part to the engine overheating during competition. The maximum safe operating temperature for our engine is 200 degrees Fahrenheit, but data taken from the ECU after the breakdown showed that coolant temps reached over 250 degrees after sitting for several minutes during the mandatory driver change, which starved the radiator of cool air.

The engine team has been running tests at UCI’s Vehicle Performance Engineering Lab to determine the specific cause of failure since the summer and are developing upgrades to keep Jinx cool. By measuring the water flow rates through the running engine at various RPMs and measuring the temperature drop from the radiator inlet and outlet, we’ve been able to measure Wraith’s overall cooling ability. Our calculations show that the previous design is insufficient for our needs, so we’re undergoing a full redesign of the cooling system to meet our current requirements. So far this year, our focus has been on reliability so that we can push the car harder and perform better in competition with less issues.

Figure 1  AFR’s Engine Development Sub-team runs tests on last year’s cooling system.
Want to support our developments and our 2020 car? Consider donating to our ZotFunder campaign here, running through 12/1/19.

How a standard water-cooled system works:

As the engine runs, it generates large amounts of heat.  In order to keep the engine temperature at 200 degrees, the excess heat is absorbed using a water-cooling system that pumps cool water through the engine block. The hot water is then passed through a thermostat which opens once the temperature of the water reaches 190 degrees. To avoid cavitation, or the creation of low-pressure pockets that interrupt water flow, the hot water is then sent to a swirl pot, which allows any steam in the system to condense back into liquid. This condensed hot water is then sent through the radiator, where heat is removed through convection, and then is sent back into the engine using a pump.

Figure 2 Block diagram for the Jinx cooling system.

The radiator performs most of our cooling by passing the engine coolant through an exposed fin setup that allows the passing air to absorb heat from the system. Increasing the temperature drop across the radiator allows our engine to run cooler and avoid overheating.

To do this:

  1. We’ll install a larger radiator as well as more powerful cooling fans to improve the airflow to the coolant.
  2. We’ll install an upgraded water pump to increase coolant mass flow through the system.
  3. We’re working with our Aerodynamics team to design a custom sidepod to maximize the amount of air that is directed to our radiator (Figure 3).

Figure 3 CAD design of Jinx cooling system.

We expect to have Jinx up and running in early 2020, stay tuned!

Dillon Smith is a fourth-year mechanical engineer on AFR’s Engine Development sub-team, which is led by Tristan Cortez and also includes Mohammed Azeem, Daniel Martinez, Mason Socha, Sangghara Kusumo, Edward Han and Dustin Ngo.