Airflow

Question 1

Elementary laws of airflow

Answer 1

• For air to flow from one point to another there must be a difference in pressure between these two points
• Air will always flow from a point of high pressure to a point of low pressure
• The larger the pressure difference between the two points, the greather the quantity of air that will flow between the two points
• if the pressure difference between two points remains the same and the resistance to airflow between the points is increases, the air quantity flowing between these points will decrease

Question 2

Resistance to Airflow

Answer 2

1. Surface roughness
2. Size
3. Length
4. Sudden change of size
5. Obstructions
6. Change in direction

Question 3

Measurement of Airflow

Answer 3

• Anemometer
• Smoke
• Pitot Tube

Question 4

Types of pressure

Answer 4

1. Velocity pressure
   - defined as the pressure created due to the movement of air
2. Static pressure
   - Defined as the pressure exerted on the walls of a container
3. Total pressure
   - Sum of velocity and static pressure

Question 5

Pressure Measuring Instruments

Answer 5

• Aneroid Barometer
• Mercury Barometer
• Water Barometer

Question 6

Shock Losses

Answer 6

• natural shock losses where air changes direction and/or velocity

Question 7

Regulators

Answer 7

• Intentionally destroy ventilating pressure by suddenly increasing/decreasing the air velocity