Aerodynamics are for Winners.

From saying aerodynamics are for people who can't build engines (-Enzo Ferrari, Founder Scuderia Ferrari) to Aerodynamics are for winners ( Mattia Binotto , Team Principle Scuderia Ferrari) . Times have changed.

Aerodynamics is the study of air , that reacts when comes in contact with the vehicle. Whatever might be the engine size , whatever might be the engine power, a little aerodynamics will definitely boost the performance to an extent. In this blog we will briefly look in to the aerodynamics in F1 car , and various aerodynamic devices used in the car.


Imagine throwing a pencil and a paper from the balcony? which lands first? Yeah , obviously the pencil. Even tho the work done by the gravity is same on both objects , the paper is slower than the pencil. The reason that makes pencil fast is the exact same reason what makes F1 cars fast. It is very important for a car to as sleek as as it can be. This not only increase the speed ( acceleration) but also increase the efficiency of the vehicle.


In the above image, If you notice there are patches of red zones in front end of the car , while a cluster of blue zones in back end of the car. The blue areas are low pressure zone , while the red and yellow are high pressure zones. When a object is under dynamic condition relative to surrounding fluids ( In this case , Air). As we know fluids move from higher pressure to lower pressure . Now the air tends to move backward. But this air is obstructed by a area of car (usually known as frontal area).Which pushes the car back.

This reduces the effect of tractive force produced by the wheels , that reduces the efficiency, speed, and acceleration of vehicle. But there are ways to overcome this force by designing a good aerodynamic structure that can sleek in to air . This is where the study of aerodynamics play a important role in vehicle dynamics.

Fluids have the tendency to follow the surface irrespective of what shape they are ( curved or straight). So by altering the shape of the monocoque in a F1 car we can reduce the drag force created by vehicle


If you notice the shape of the vehicle from the top view it resemble a little of water droplet.

If you look at the above image of the CFD analysis. You might see there are no or less blue zones at the rear , and the pressure difference is very less (Red to Yellow , while it was Red to blue in Cybertruck)
Due to the less pressure difference , the force the car is dragged back is less. How this is achieved? as i previously said . The fluid follow the path of surface. Now the air follows the curve back to car. This increase the pressure relatively high than before reducing the pressure difference and so drag is less. Making the car more sleeker. Depending on how sleek the shape is , the drag coefficient decreases. So more sleeker the object, less the drag coefficient.


Okay , that's it for this week, but my conscience will prick me if i leave the topic here. Let us see the
as usual breaking the law part that F1 car, which it did all blogs before ( using small engines for more power, Using slick or grove less tires for more grip ).


You read more sleeker the car, less the drag coefficient , but in reality F1 cars have drag coefficient up to 1.1 while the boxy SUVs will have around 0.3. As we talked about the importance of grip between road and tire, aerodynamics plays important role in increasing the grip between road and tires by increasing the normal force. It is not only important for a car to have high speed, it is equally important to maintain the speed in turns and curves. The speed the car can turn the curve is limited by the grip of the car.





When the car turns , the linear velocity of the car is now changed to rotational velocity with respect to ground frame. This leads to several force that act on the body.

1. Centripetal Force

2. Centrifugal Force

Centripetal force is a force that move the car inside the turn ( lateral force) , so that the car moves in the circle ( or arc of some radius). But inertia is not always a benefit like it was for MGU-K. Since the car is turning in one direction . The inertia pushes the car opposite to the direction. At lower speed the centrifugal force is not enough to push the car out of track, but higher speed , when the friction doesn't favor the lateral force ( Refer Blog Tyre dynamics for more understanding) the car tends to slide or sometimes even topple because the effectiveness of centripetal force is less due to less grip. This force that pushes the car outside the turn is called centrifugal force.

How can we determine the maximum speed that the car can turn?

Centrifugal force = 0.5 x M x V x V/R

Friction force that grip the tire with road = μs( Static Friction Coefficient ) x N( Normal Force) .

There is a point the which the car handle maximum speed and the condition is

Centrifugal Force = Frictional force

so

0.5 x M x V x V/R  = μs( Static Friction Coefficient ) x N( Normal Force) .

V = ( √2 x μs x N x R)/ M

So we have derived the formula for the maximum speed , From the formula it is clear that the maximum speed in turn is limited by radius of turn , coefficient of friction , normal force and inversely proportional to mass. But if you notice and Mass , Radius of track and coefficient of friction cannot be changed to our convenience. The only thing I can change is Normal force. you might ask weight on ground is always proportional to normal force for horizontal surface. Yes, but what if I increase the vertical component force, The normal force increases. This can be achieved dynamically by aerodynamics forces . This is exactly where Wings and other aerodynamic device comes in to action.


In next week , we will look into the working of these aerodynamic devices.