Page 14 - BASIC CONCEPTUAL OF THERMOFLUID
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CHAPTER 1: CONCEPTUAL PRINCIPLE IN THERMOFLUIDS
Example 1.1
What is the pressure gauge of air in the cylinder if the atmospheric gauge is 101.3 kN/m2 and absolute pressure
is 460 kN/m²
Solution:
Pabs = Patm + Pgauge
Pgauge = Pabs − Patm
3
3
Pgauge = (460 × 10 ) − (101.3 × 10 )
Pgauge = 358.7 kN/m²
1.9 Fluid Properties
a) Mass density, ρ is defined as the mass per unit volume.
= ( ),
3
= , =
b) Specific weight, is defined as the weight per unit volume.
=
= ( )
3
c) Specific gravity or relative density, s is the ratio of the weight of the substance to the weight of an
equal volume of water at 4 ºC.
= =
d) Specific volume, v is defined as the reciprocal of mass density. It is used to mean volume per unit
mass.
1
3
= , = , : /
10
