Carbon FIber 2019-2021 BMW X4M F98 3D Design Style Rear Diffuser For X4M F98

When cars first entered human life, they paid more attention to the power system and body structure, and there was little research on design, such as appearance and fluid mechanics. Later, as the engine horsepower gradually increases, the vehicle's driving speed becomes faster and faster. In this high-speed state, the disadvantage of unstable driving of the vehicle is concentrated. In addition, the huge lifting force of the air also makes the vehicle's grip significantly insufficient, and the vehicle is clearly in a floating state, which is a very dangerous hidden danger.

In order to solve this problem, engineers have put in great effort in optimizing aerodynamics. Currently, the most common approach is to install components such as a spoiler that can increase downforce on the vehicle body. Although this is a conventional practice and the cost can be controlled, the disadvantage is that by increasing airflow resistance in exchange for downforce, the resistance will significantly increase during driving.

What is a tail diffuser?

The rear diffuser combs the bottom airflow to allow air to pass through the chassis faster and smoother, making the air flow rate in the upper part of the vehicle lower than that in the lower part. This can generate stronger downward pressure, make the vehicle's high-speed posture more stable, and usher in a huge improvement in vehicle performance.

In order to avoid the problem of resistance caused by increased downforce, automotive engineers have also conducted multiple verifications and studies, and concluded that the best solution under current conditions is to install a diffuser at the rear. The working principle of this component is to install an upward deflector at the rear of the car, which quickly draws out the airflow from the bottom of the car. The higher the airflow speed, the lower the pressure, and a low-pressure zone is formed under the car. The roof part is a high-pressure zone, and the pressure on the roof is greater than the pressure on the bottom, causing the car to form a downward force and be firmly "nailed" to the road.

When the fluid passes through a narrow section, the flow rate increases, and the area that truly forms downward pressure is the car bottom rather than the diffuser. The fastest part of the gas flow rate is the car bottom in front of the diffuser, which only helps the vehicle generate huge downward pressure to press the vehicle onto the road surface.

Diffusers have advantages over spoilers and other devices, as they do not generate additional air resistance. However, they also have significant limitations, as in order for the diffuser to achieve sustained and stable downforce, the road surface must be very flat, otherwise it is difficult to form a stable low pressure under the vehicle. Therefore, diffusers are generally used in racing or supercars, and are generally driven on mountain roads or uneven roads, making it difficult to fully utilize their effectiveness.