TABLE OF CONTENTS On reading this chapter, the student will be able to:
Explain and understand the various terms and definitions used in hydraulics
Understand the significance of Pascal's law and its applications
Understand the importance of flow and pressure in hydraulics.
Pressure along with flow is one of the key parameters involved in the study of hydraulics. Pressure in a hydraulic system comes from resistance to flow. This can be best understood from Figure 2.1.
Consider the flow from a hydraulic pump as shown. Here the pump produces only flow and not pressure. However any restriction in the flow from the pump results in the formation of pressure. This restriction or resistance to flow normally results from the load induced in the actuator. The various conductors and components of the hydraulic system such as pipes and elbows also act as points of resistance and contribute to the generation of pressure in the system.
Pressure ( P) is defined as the force ( F) acting normally per unit area ( A) of the surface and is given by the equation:
Pressure in the SI unit is measured in terms of N/m 2 also known as a Pascal. Pressure can also be expressed in terms of bar, where
Pressure in the US unit is measured in terms of lb/in. 2 or psi, where
Fluids are composed of molecules, which are in continuous random...
