Fluid Fundamental Concepts
Definition of a Fluid
Fluid is defined as a substance that deforms continuously whilst acted upon by any force tangential to the area on which it acts.

Fluid Properties
The  properties of fluids permit us to distinguish  one fluid from another,  and  they  allow us to make estimates of physical behavior  of any special fluid.

Fluid  statics  is that branch  of mechanics  of fluids that deals primarily  with  fluids at rest.
Distribution of Pressure in the Fluid
The  cross sectional  area  δA is very  small and  the variation  of pressure  over it therefore negligible

Hydrostatic Pressure
The direct proportionality between hydrostatic pressure  and h for a fluid of constant density  enables  the pressure  to be  simply  visualized  in terms  of the vertical  distance h = p/ρg.

ISO VG for Engine Oils
ISO VG for Engine Oils and their Kinematic Viscosity at 40 degC