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) |
|---|---|---|
| Ethanol | 896 | 1070 |
| Benzene | 1060 | 1540 |
| Biodiesel (from Rapeseed Oil) | – | 1733 |
| Carbon Disulfide | 1075 | – |
| Carbon Tetrachloride | 958 | 1410 |
| Diesel Fuel | – | 1545 |
| Glycerin | 4510 | 4960 |
| Kerosene | 1300 | 1440 |
| Machine Oil | 1300 | 1510 |
| Mercury | 24800 | 28600 |
| Water, Fresh | 2180 | 2200 |
| Water, Salt | 2340 | 2370 |
Further Reading
- Marks’ Standard Handbook for Mechanical Engineers 11th Edition
- University Physics with Modern Physics (13th Edition)
- Bulk Modulus of Vegetable Oil-Diesel Fuel Blends. Varde
- Determining the Speed of Sound, Density, and Bulk Modulus of Rapeseed Oil, Biodiesel, And Diese Fuel. Nikolic et. al.
