UNIT-1 BASIC PROPOERTIES OF FLUIDS
UNIT –1: BASIC PROPERTIES OF FLUIDS:
1.0 INTRODUCTION: In general matter can be distinguished by the physical forms
known as solid, liquid, and gas. The liquid and gaseous phases are usually combined and
given a common name of fluid. Solids differ from fluids on account of their molecular
structure (spacing of molecules and ease with which they can move). The intermolecular
forces are large in a solid, smaller in a liquid and extremely small in gas.
Fluid mechanics is the study of fluids at rest or in motion. It has traditionally been
applied in such area as the design of pumps, compressor, design of dam and canal, design
of piping and ducting in chemical plants, the aerodynamics of airplanes and automobiles.
In recent years fluid mechanics is truly a ‘high-tech’ discipline and many exciting areas
have been developed like the aerodynamics of multistory buildings, fluid mechanics of
atmosphere, sports, and micro fluids.
1.1 DEFINITION OF FLUID: A fluid is a substance which deforms continuously under
the action of shearing forces, however small they may be. Conversely, it follows that: If a
fluid is at rest, there can be no shearing forces acting and, therefore, all forces in the fluid
must be perpendicular to the planes upon which they act.