Compressibility of Fluids Review and Equation

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Compressibility of Fluids Review and Equation

Compressibility is the measure of the change in volume a substance undergoes when a pressure is exerted on the substance. Liquids are generally considered to be incompressible. For instance, a pressure of 16,400 psig will cause a given volume of water to decrease by only 5% from its volume at atmospheric pressure. Gases on the other hand, are very compressible. The volume of a gas can be readily changed by exerting an external pressure on the gas

Equation:

where V is volume and p is pressure

Earth Vertical, drained compressibilities

Vertical, drained compressibilities Material β (m²/N or Pa-1)

Vertical, drained compressibilities Material β (m²/N or Pa −1 )
Material
β (m2/N or Pa -1 )
Plastic clay
2 × 10-6 – 2.6 × 10 -7
Stiff clay
2.6 × 10 -7 – 1.3 × 10-7
Medium-hard clay
1.3 × 10 -7 – 6.9 × 10 -8
Loose sand
1 × 10 -7 – 5.2 × 10 -8
Dense sand
2 × 10 -8 – 1.3 × 10 -8
Dense, sandy gravel
1 × 10 -8 – 5.2 × 10 -9
Rock, fissured
6.9 × 10 -10 – 3.3 × 10 –10
Rock, sound
<3.3 × 10 –10
Water at 25 °C (undrained)
4.6 × 10 –10
Ethyl alcohol
110 × 10 –11
Carbon disulfide
93 × 10 –11
Glycerine
21 × 10 –11
Mercury
3.7 × 10–11