Exemple de conception : calcul du diamètre de sécurité d'un disque exposé au vent

A circular disc, 4 meters in diameter, is to be installed on a building as an aesthetic feature. 
The disc has to face wind with a density of 1.25 kilograms per cubic meter and a velocity of 25 m/s, perpendicular to its surface, with a drag coefficient of 1.1.
The disc has to be held securely on a wall-mounted projection capable of providing a reaction force of 3250 Newtons.
All other design parameters are assumed safe. For safety, the engineer must ensure the drag force on the disc is less than the reaction force provided by the wall member.
Upon calculating the drag force on the disc, it was found to exceed the reaction force that the wall member can withstand, indicating an unsafe condition.
The engineer begins by equating the drag force to the reaction force to calculate the required area of the disc, ensuring the drag force does not exceed the wall member's capacity.
Finally, the engineer decided to reduce the disc's diameter to 3 meters to ensure safety before installation.