Summary

The bulk modulus or elasticity is a measure of the resistance to compression of a substance. This article presents the bulk modulus for various liquids.

Definitions

:Isothermal bulk modulus of elasticity
:Isentropic or Adiabatic bulk modulus of elasticity


Bulk Modulus for Liquids

The bulk modulus for a liquid is defined as the ratio of a change in pressure to the relative change in volume. Common uses for the bulk modulus include:

  • Calculation of the speed of sound for liquids, which useful for applications where pressure waves are important like dynamics modelling and surge analysis.
  • Determination of the lag in response time for hydraulic systems.

Properties for various liquids at 1 atm and 20°C are shown in the table below.

Liquid Isothermal
MPa
Isentropic
MPa
LiquidK(t)K(s)
Ethanol8961070
Benzene10601540
Biodiesel (from Rapeseed Oil)-1733
Carbon Disulfide1075-
Carbon Tetrachloride9581410
Diesel Fuel-1545
Glycerin45104960
Kerosene13001440
Machine Oil13001510
Mercury2480028600
Water, Fresh21802200
Water, Salt23402370


Further Reading

  1. Marks' Standard Handbook for Mechanical Engineers 11th Edition
  2. University Physics with Modern Physics (13th Edition)
  3. Bulk Modulus of Vegetable Oil-Diesel Fuel Blends. Varde
  4. Determining the Speed of Sound, Density, and Bulk Modulus of Rapeseed Oil, Biodiesel, And Diese Fuel. Nikolic et. al.