Ch 3 - Describing And Understanding Airflow

Question 1

Equation of Continuity

Answer 1

Works on the principle that mass cannot be created or destroyed -> A constant mass flow

-> Air mass flow entering a stream tube must remain the same at all points along it

AVp = Mass Flow = Constant Value

Question 2

Bernoulli’s Theorem

Answer 2

Works on the principle that energy cannot be created or destroyed, only changed from one form to another.

The sum of the static pressure + the kinetic energy (per unit volume) = Constant

Question 3

Total Pressure =

Answer 3

= Static Pressure + Dynamic Pressure

Question 4

The 3 types of airflow:

Answer 4

• Laminar (smooth, uniform)
• Turbulent (unsteady)
• Vortex (elements of laminar and turbulent)
  
  • > Steady flow on a helical path which eventually dissipates
  • > Detailed flow may be turbulent

Loses energy to surrounding air
-> Becomes slower and larger before this happens

Question 5

Ideal Fluid Properties

Answer 5

• > Incompressibility

- > No Viscosity

Question 6

Venturi Effect

Answer 6

When airflow lines get converge together, increasing in speed and then diverge losing speed