Module 5: Gas Flow

Description: Describes the movement of gas molecules under different pressure conditions.

Length of Time: 3 hours

Topics:

1. Turbulent flow

2. Viscous (laminar) flow

3. Intermediate flow

4. Molecular flow

5. Speed, throughput, and conductance

 

Student Objectives:

Student will be able to:

1. Define the following types of flows: turbulent, viscuous, intermediate, and molecular.

2. Relate the different gas flows to the pressure regions: low, high, and ultra high.

3. Identify component geometry for the different pressure flow regimes.

4. Define the terms: throughput and conductance.

5. Given a component data sheet or catalog, find the conductance value for a given vacuum system component.

6. Use the term "throughput" to describe vacuum systems, pump operation, and gas load.

References:

Chambers: Chapter 2 "Gases in Vacuum Systems"

O’Hanlon: Chapter 3 "Gas Fow"

Varian: Chapter 1 "Vacuum Fundamentals"