Hydraulics

Hydraulics refers to the study of a liquid's mechanical properties while in motion, and the application of that knowledge in design and control of machines.

For example, hydraulics is used when looking at the flow of liquids in pipes, pumps, rivers, and channels, and their confinement by dams and tanks.

Modern hydraulic-technology is based on Pascal’s law. Formulated in about 1650, the law states that pressure in a liquid is transmitted equally in all directions - ie. when you put water into a container, the application of pressure at any point will be transmitted to all sides of the container.

With hydraulics, Pascal’s law is used to gain an increase in force through the use of actuators. Hydraulic actuators consist of a cylinder or fluid motor that uses hydraulic power to facilitate mechanical operation. The mechanical motion gives an output in terms of linear, rotary or oscillatory motion. Because liquids are nearly impossible to compress, a hydraulic actuator can exert a large force. The drawback of this approach is its limited acceleration.