Aerodynamics of a Ram Air Duct | Horn/Flare Design

Horn/Flare Design

At low vehicle speeds, the engine does all the work to create a region of low pressure in the cylinders (vacuum work) such that the ambient air pressure is greater and produces flow, this produces net flow into the engine at a cost of pumping losses. One way to reduce vacuum work and to make it easier for the engine to draw in air, is by using a properly designed converging horn/flare. The BIG MOUTH ram air intake snorkel uses a compound radius inlet horn on its inlet to promote low vehicle speed airflow.

Horn/Flare Design | Velossa Tech Design