Fluid mechanics

Fluid Mechanics

Fluid mechanics is a branch of continuous mechanics which deals with the study of all fluids under static and dynamic situations.

Fluid statics

mechanics of fluids at rest

Kinematics

velocities and streamlines w/o considering forces or energy

Fluid dynamics

Fluid relations between velocities and accelerations and forces exerted by or upon in motion

Hydraulics

application of fluid mechanics to engineering devices involving liquids

Gas dynamics

flow of fluids that undergo significant density changes

Aerodynamics

flow of gases,

solid can resist ?

shear stress by a static deformation

Rheology

is study of materials showing dual behaviors behaves like solid and under others behaves like fluid

Continuum

assume fluids are continuously distributed throughout the region of interest.

Newtonian Fluid

deform at different rates under the action of the same applied shear stress. water, air & gasoline

Non-Newtonian Fluid

Fluid in which shear stress is not directly proportional to deformation rate toothpaste and Lucite paint.

Incompressible fluids

fluids that do not undergo significant changes in density as they flow.

Compressible fluids

fluids that undergo significant changes in density as they flow.

Dilatants

shear thickening fluids, become more resistant (more viscous) to motion as the strain increases

Pseudoplastics

shear thinning fluis, become less resistant to motion with increased strain rate

Bingham fluids (ideal plastics)

require a minimum shear stress to cause motion.

Dimension

measure by which physical variable is expressed quantitatively.

unit

quantitative dimension.

Mass (m)

amount of matter in a particle or object. (Unit: kg, g, and slug)

Weight (W)

force that gravitation exerts on a body.

(W)

mg; g = acceleration due to gravity (9.81 m/s2or 32.2 ft/s) Newton (N) and pound force (Ib)

Density (p)

mass per unit of volume.

Specific volume (Vs)

volume occupied by a unit mass of fluid. It is the reciprocal of density.

Unit weight or specific weight (y)

weight per unit volume.

Unit weight or specific weight

W = weight (N or Ibs) and V volume (m or ft)

Specific gravity (sg) - (or relative density)

unitless ratio of a fluid's density to some standard reference density. the reference density is water at 4°C. p=1000 kg/ m2; v= 9.81 kN/ m or 62.4 Ib/ ft thought as

Absolute or Dynamic viscosity (u)

thought the internal stickiness of a tluid; that is due to its resistance to shear stress

Kinematic viscosity (v)

ratio of the dynamic viscosity of the fluid to its density.

Kinematic viscosity (v)

m/sec and Stoke- 1 cm/sec