Caeli - Design for Automotive

Design Parameters

Along with aesthetics, ergonomics and aerodynamics were the main parameters that were considered while designing the car. The following research has been done, and corresponding design decisions were taken.

Ergonomics:

Racers have to experience severe strain during racing, experiencing forces up to 6 g's on occasions, and races extending to two hours each time. Hence, for the optimal performance of the driver, the driver's ergonomics have to be considered very carefully.

As part of ergonomics, we consider all the systems that the driver is in direct interaction with. Hence, the following are considered: the seat, harness, steering wheel, pedals.

Car seat:

Due to the Formula 1 car constraints, the car's seat has to be as low as possible, to reduce the center of gravity of the vehicle.

Each car seat is molded for the driver, which fits him perfectly, and is made of carbon fiber to have the least weight and highest toughness. Though the material is hard, it ends up being comfortable as it perfectly fits the driver's anatomy.

Car seat that is custom molded to the driver

4-point seat harness:

A minimum of 4-point seat harness is required to keep the driver in place when he is cornering and braking. This seat harness is also used when the driver has to be quickly pulled out of the car if required in an accident.

The button in between releases all the harness simultaneously in case the driver has to come out of the seat quickly.

Steering wheel:

Contrary to the standard vehicle, most of the controls for the driver are located on the steering wheel, including shifting the gears up and down. The two legs only have the function of acceleration and deceleration.

Even a steering wheel is heavily customized to the driver, and the button placements are usually changed according to their preference.

Aerodynamics

The critical phenomenon that has to happen on an F1 car is that there has to be a balanced downward force on both the front and rear sides. This downforce can be achieved using the aerodynamics of the car, and more importantly, the front and the rear spoilers of the car.

Front Spoilers:

The function of the front spoilers is to provide enough down force so that the car can take a turn properly. Failing to do so results in incomplete turning, called the understeer.

The more the car's speed, the more the downforce of the front spoilers on the front tires.

Rear spoilers:

The function of the rear spoilers is to provide downforce so that the rotation of the rear tires translates to the ground. If there is not enough downforce in the rear, it causes the tires to slip on the road during acceleration and the car to oversteer when in a turn.

The faster the car goes, the more downforce that is created in the rear.

Side fins located behind the front tires

p

One of the biggest problem with respect to the air flows around a vehicle is the turbulent wakes that are formed in the gaps between the front and the rear tire. Turbulent wakes are not favorable as they are tough to control, and hence is tough to convert them to useful downward forces.

Use of fins helps us to reduce the amount of turbulent wakes that are created, and guides the air flow as required.

CFD Analysis

A wind tunnel analysis has been done on Caeli. Here, we see the strongest forces are being created near the nose of the body, the tip of the tires, and the rear spoiler.

Turbulent wakes are also plotted in the gap between the front and rear tires and behind the rear spoiler. The size of turbulent wakes has reduced by the use of fins, thereby proving the use of fins between the front and the rear tires.

Turbulent wakes behind the front and rear wheels

Full analysis in Autodesk Flow Design