Heat Of The Moment

With hugely complex systems and restrictive regulations, engineers working in the field of electric racing have been forced to come up with ever-more ingenious methods to cool their motors, inverters and batteries

- Gemma Hatton

The concept of cooling for an internal combustion racecar is a familiar one. Ambient air flows into radiators within the sidepods, which reduces the temperature of the coolant flowing within those radiators. This coolant is then pumped around a closed-loop system and absorbs heat radiating from the engine and other components. This now hotter coolant flows back to the radiators where it is cooled down, and the cycle begins once again.

However, the top tiers of racing are now either hybrid or electric and consequently running high voltage batteries, motors and inverters. So how does the cooling system work on these hybrid and electric racecars?

Heat is often the number one enemy of any engineer, because when energy is converted into heat it’s usually because it hasn’t been converted into useful work. Despite 160 years of development, internal combustion engines in road cars are still only around 30 per cent efficient. This means that for an IC engine consuming 200kW of power from burning fuel, roughly only 55kW will be converted into useful motion. The rest is losses; with around 125kW of those losses emitted as heat, either through the exhaust gases or radiators.

Racing engines, on the other hand, are much better, with the modern Formula 1 powerplant reaching 48 per cent efficiency, with some rumoured to be 50 per cent efficient. Yet while this is an astounding achievement – which has been poorly advertised in our modern eco-warrior world – this still means that up to 52 per cent of the energy produced is lost through heat, sound, and various other forms.

Electric fan