Chapter 2: Fluid Properties

Solid-Liquid-Gas

Specific Weight

Compressible vs. Non-Compressible

Solid under shear vs Liquid under Shear

Viscosity

Newtonian vs. Non-Newtonian

Surface Tension

Vapor Pressure

Some properties of fluids

• Solid – Fluid Solid – liquid – gas– How to best distinguish between them?– Solid properties, and response to container

boundaries

• Mass, density, weight, and the “specifics”

Solid-Liquid and Gas

A given mass of liquid will maintain its volume but change its shape to match that of the container where they are in contact.

Dimensions, Units, etc.

Some more fluid properties

• Solid – Fluid: how does each respond to an applied shear stress?– (How about a applied pressure stress?)

• Viscosity and rheology

• What sort of forces does a fluid exert?– Surface tension– Vapor pressure

ly

What about shear stress?

Top layer of fluid moves with velocity of block

Imagine an elastic solid held between two Plates-and then applying a shear force To the top plate

Then imagine a long open tank (flume) holdingwater with a wood block floating on the surfaceAnd then apply a shear force to the wood

Bottom layer does not move—The NO SLIP condition

Contrast to solid

u

displacement

dy

duG

shearmodulus

Strain-deformation

Surface Tension

Why 2

Note dependence on RRecall g is specific weight

Vapor Pressure

Boiling will occurIn Denver the atmospheric pressure is only 95% (see page 40)On Everest only 75%--the boiling points are reduced accordingly