PPT Slide
Basic Fluid Properties and Governing Equations
- Density (?): mass per unit volume (kg/m3 or slug/ft3)
- Specific Volume (v=1/r): volume per unit mass
- Temperature (T): thermodynamic property that measures the molecular activity
of an object. It is used to determine whether an object has reached thermal
- Pressure (p):pressure can be considered as an averaged normal force exerted
on a unit surface area by impacting molecules.
( , N/m2 or pascal; lb/in2 or psi)
Pascal law: (under static condition) pressure acts uniformly in all directions. It also
acts perpendicular to the containing surface.
If a fluid system is not in motion, then the fluid pressure is equal its thermodynamic
- Atomspheric pressure (patm): pressure measured at the earth’s surface.
1 atm = 14.696 psi = 1.01325 x 105 N/m2 (pascal)
- Absolute pressure: pressure measured without reference to other pressures.
Gage pressure: pgage= p absolute - patm