Chapter 1 - Properties of Fluids

Fluid Mechanics is a physical science dealing with the action of fluids at rest or in motion, and with applications and devices in engineering using fluids.
Fluids mechanics can be subdivided into two major areas:
- Fluid Statics
- Fluid Dynamics
Fluid Statics deals with fluids at rest.
Fluid Dynamics is concerned with fluids in motion.
Hydrodynamics is applied to the flow of liquids or to low-velocity gas flows where the gas can be considered as being essentially incompressible.
Hydraulics deals with the application of fluid mechanics to engineering devices involving liquids, usually water or oil.

Fluid refers to any substance that is capable of flowing.
Fluids are generally divided into two categories.
- Ideal Fluids
- Real Fluids
Ideal Fluids are fluids that have no viscosity, incompressible, no resistance to shear, no friction between moving layers of fluid, have uniform velocity when flowing, and no eddy currents or turbulence.
Ideal Fluids can be referred to as “Perfect Fluids” as it has no friction nor viscosity.
Real Fluids are fluids that exhibit infinite viscosities, compressible, have non-uniform velocity distribution when flowing, and experience friction and turbulence in flow.
Real fluids are further divided into:
- Newtonian Fluids
- Non-Newtonian Fluids
Classification of Fluids:
- Gases
- Liquids
Gases are fluids which have little resistance to change either in form or volume and occupies all the space in which it is contained.
Liquids are fluids which offer great resistance to change in volume and occupies a definite portion in which it is contained.

Mass (m) is the quantitative measure of the amount of matter in a given body.
- FORMULA: m = W/g
Density (
- FORMULA: