Fahrtwind

Fahrtwind is a term used in German to describe the wind experienced by a moving object as it travels through air. It denotes the component of the wind created by motion, i.e., the relative or apparent wind resulting from the combination of ambient wind and the motion through the air. The concept is used in meteorology, aviation, sailing, and sports to describe how motion affects aerodynamic forces.

The perceived Fahrtwind depends on the object's speed and direction, and on the true wind. It is not a fixed wind, but the wind velocity acting on the surface of the moving body. In practice, faster travel increases the magnitude of the Fahrtwind, altering drag, lift, and thermal sensation.

In cycling, Fahrtwind influences comfort and cooling; in automotive testing, it affects aerodynamics and climate control demands; in sailing, the Fahrtwind forms part of the apparent wind that determines sail trim and propulsion; on bicycles or cars, it affects drag, cooling, and occupant comfort.

Etymology and usage: The word Fahrtwind combines Fahrt ('travel') and Wind ('wind'). It is used primarily in German-language discussions of wind effects related to motion; the term has no precise international technical designation and is often described using the broader concept of apparent wind.