One of the trickiest aspects of managing a Formula 1 car is cooling its components, because of the very high temperatures that some of them can reach during a session on track. Marco Arini, Senior Test Engineer and Project Leader Vehicle Testing for Scuderia AlphaTauri tells us more.
Which components get hottest on a Formula 1 car?
If we exclude the combustion chamber of the internal combustion engine, there are three: the turbine, the exhausts and the braking system, comprising the discs and pads. These components are by far the ones that get hottest on the car.
On the subject of brakes, how important is it to manage temperatures and how does it influence car performance? And how do you keep it under control?
Brake temperature management is one of the most critical aspects of brake system management. For the carbon ceramic discs to generate the maximum friction coefficient, they must operate within an optimal working range. We constantly monitor the entire braking system with a series of sensors that measure temperature, pressure and displacement. Specifically, the measurement of disc brake temperature is standardised and checked with infrared sensors positioned within a few millimetres of the disc, located inside the brake duct. These can detect temperatures of up to 1200 degrees centrigrade. Using telemetry that detects the disc temperature, countermeasures can be taken immediately any anomalies or performance drops are noticed.
What is the most critical moment for brake management?
The opening laps of a Grand Prix are the most critical when it comes to managing temperature, when values of over 600 to 700 degrees can be seen. In traffic, turbulence from the cars in front reduce the volume of air that reaches the cooling brake ducts. Dissipating the heat generated from the air that passes through are the ventilation holes in the discs themselves.
How much has the management and the importance of the brakes changed since the start of the hybrid era in 2014?
The advent of the hybrid era, with the introduction of brake-by-wire, has introduced new variables in brake management, but the vital role they play in terms of performance and safety has remained the same: slowing an 800 kilo car from over 300 km/h down to 80 km/h in just over 100 metres and in around 2 seconds, requires a system that is efficient and perfectly sized, capable of using all the potential of the brake disc.
Drivers can brake in different ways. Does this require different brake settings?
Before an event, there are various elements that can affect the choice of brake cooling specification. In particular:
- The type of braking material
- Track characteristics, (the difference between a low and high duty track)
- Ambient conditions, for example atmospheric pressure. An extreme example of this would be Mexico City, where the air is particularly rarified.
- The weather
The influence that temperatures generated by the discs can have on tyre performance. These are some of the elements that have to be taken into consideration. Driving style and a different balance, which to varying degrees can impact the energies involved during braking, have also to be considered, but in general, these factors are not of primary importance when it comes to choosing the configuration.
Brake-by-wire and MGU-K: if you had to explain it to your mother-in-law what would you say?
The MGU-K (Motor Generator Unit – Kinetic) along with the MGU-H (Motor Generator Unit – Heat) and the battery (Energy Store) make up the ER, or Energy Recovery System. It’s been in use since 2014 with the advent of the turbo-hybrid power unit. It is all run by a central control unit.
The MGU-K is an electric unit connected to the crankshaft and it has a dual role: under braking, it works as a generator and contributes to slowing down the car, converting part of the kinetic energy into electrical energy. This is then stored in the battery; under acceleration, it works as a motor and generates increased engine torque (up to 160 hp) delivered in the exit of the corners. Clearly, the hybrid part plays a vital role in the dynamics of the car. In order to ensure the correct balance and stability required by the driver, it is necessary to use an electrical braking system, known as brake-by-wire. The concept is very simple: as the car decelerates, the central control unit, depending on the contribution of the MGU-K, sets how much braking force must be provided by the rear braking system, by setting a target pressure at the caliper. Management of these control parameters and the accuracy of the friction maps of the braking material used by the brake-by-wire are vitally important to ensure the response of the system with the correct demands made by the discs and pads. A failure of the BBW system is one of the most serious that has to be managed in order to ensure the safety of the driver and it usually means the car has to be stopped and retired immediately.
The 2022 regulations: we will have 18 inch wheels, the disc size will go up from 278 to 330 mm; the brake ducts that direct cooling air onto the brakes will be a common part for all teams: what will be the effect of this scenario in your view? What new challenges will arise, in what areas is there room for development?
Every change to the regulations always throws up new challenges. One’s ability to develop the car design within the stringent regulations to be introduced for next year definitely makes everything more complicated, but at the same time, it’s very exciting. Regarding the braking system, one of the most important aspects will be how to deal with the limits imposed by the new technical directives, especially those relating to the effect of disc temperature on the tyre operating temperatures. Obviously, the cooling efficiency of the disc and caliper remains a key area of car development.
When and how did you join our team?
I started working in Formula 1 in 2005. After a short time in the technical office, in the aerodynamic department, I joined the group of track engineers, as a Performance Engineer, at tests and races up until 2012. Then I became factory-based and today I am the head of vehicle testing and brake systems within the Vehicle Performance Group.