A venturi tunnel is defined by how air flows through it compared to an external flow like a car's underbody.
Understanding a Venturi Tunnel
Based on the provided information, a key characteristic of a proper venturi tunnel is the nature of the airflow within it:
- Internal Flow: A venturi tunnel is a system where the airflow is entirely contained within its structure.
- Forced Direction: Crucially, in a venturi tunnel, air has no choice but to go through it. This means the air path is defined and enclosed.
This is contrasted with an external flow, such as the air moving around and under a car's underbody (like the pre-2022 designs mentioned in the reference). In that external scenario, air has options; it can "choose" to go under or over the car.
Therefore, the defining feature highlighted is the mandatory, internal pathway that air must follow within a venturi tunnel, as opposed to the optional, external pathways air can take around a simple flat floor or other external surfaces.
