This question has been posed by every person who once owned a convertible car, not just once. But hardly anyone knows the answer.
In order to understand this problem, it is sufficient to know the basics of fluid mechanics, in this case, the aerodynamics.
Drivetribe’s team explains it in the simplest way in a brief video explaining the fundamental laws of fluid mechanics.
Above all, it should be known that there are two types of airflow – laminar and turbulent.
The air in the laminar layer is slow and low pressure, and in turbulent conditions it moves quickly and the pressures are high.
The air layer in contact with the car’s surface is the boundary layer, and the point of separation is the highest part of the automotive front glass (windscreen). At that point there is a separation of the part of the turbulence that becomes turbulent.
The conclusion is imposed by itself and says that the shape of the airflow will depend on the speed and angle of the windshield.
The larger the angle, the turbulent airflow will be generated faster. For example, for Mazda MX5 or BMW Z4 cars, it’s enough to drive at a speed of 72 km / h to stay dry.
The aerodynamic shapes like Ferrari’s silhouette should be driven faster. That’s why, some Mercedes models have air deflectors that affect airflow.