Plenum Chamber

Plenum chamber burning.

In the context of aircraft, a plenum chamber is a pressurized housing or chamber that equalizes and distributes air (or other fluid) flow, often used for engine cooling or to ensure even pressure distribution in systems like wind tunnels or altitude chambers.

Here's a more detailed explanation:

Function:

• Equalization and Distribution: The primary function of a plenum chamber is to equalize pressure and distribute air (or other fluid) flow more evenly.
• Engine Cooling: In some aircraft, plenum chambers are used to force air onto the engine, increasing airflow pressure for cooling purposes.
• Wind Tunnels/Altitude Chambers: In wind tunnels and altitude chambers, plenum chambers are used to ensure a stable and uniform flow of air.

Characteristics:

• Pressurized Housing: A plenum chamber is a sealed or semi-sealed space that contains a fluid at a positive pressure.
• Large Volume: Plenums are typically relatively large in volume, which helps to ensure a low velocity of the fluid flow within the chamber.
• Upstream Location: In many applications, the plenum chamber is located upstream of the fluid flow, where the fluid initially resides.

Examples:

• Engine Cooling: Some homebuilt aircraft use plenum chambers to force air onto the engine for cooling.
• Inlet Plenums: In wind tunnel testing, inlet plenums are used to ensure a stable and uniform flow of air into the test section.
• Altitude Chambers: Altitude chambers use plenums to create a simulated altitude environment.