Basic Definitions and Fluid Properties

In order for the continuum assumption to be valid, Knudsen Number K_n should be

• < 1

• > 1

• < 0.1

• > 0.1

The continuum assumption can fail if

• The fluidic system has a very large length scale

• The number of molecules is low

• The molecular mean free path length is small

• The molecules can move around freely

If a gas has a specific weight γ = 14 N/m³, what is its density?

• 1.4 kg/m³

• 5.3 kg/m³

• 8.6 kg/m³

• 12.3 kg/m³

Which of the following statements is correct for incompressible flow?

• The fluid properties do not change with time.

• The fluid properties do not change with space.

• The Mach number is greater than 0.3.

• The density is constant throughout the flow.

There is a linear relationship between the shear stress and shear strain rate of Newtonian fluids.

• True

• False