Fluid Mechanics Introduction - Properties of Fluid - Fluid Mechanics

Fluid Mechanics  INTRODUCTION • Very strong intermolecular attractive forces exist in solids which give them the property of rigidity. These forces are weaker in liquids and very weak in gases. A solid has volume and shape, a liquid has volume but no shape and a gas has neither. • A fluid is a substance which deforms continuously under the action of shear stress, regardless of its magnitude. Hence, both liquid and gas are fluids. • In liquids the molecules are so closely spaced that strong molecular cohesive force compels the fluid to behave as a continuous mass. • Density is mas per unit volume. r = = • Specific gravity =   • Specific weight = dg The specific weight of water under normal condition = 9.81 × 10 3 N/m3 . • Specific volume: It is the volume occupied by a unit mass of fluid. It is commonly applied to gases. Specific volume = . • Viscosity is the property by virtue of which a fluid offers resistance to the movement of one layer over another adjacent layer under the...