Page 86 - Industrial Ventilation Design Guidebook
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4.1 FLUID FLOW 5 1
or
where k is an empirically determined constant, ror water vapor (H>O)
k = 1.3.
4,1.5 Liquid Flow
In this section incompressible liquid flow is dealt with, and the effect of com-
pressibility is ignored.
4,1,5.1 Energy Equation
The energy equation of a continuing system can be presented by
means of the first law of thermodynamics and the energy balance of a
flow system as
As the potential energy term has an essential meaning in hydrome-
chanics, the static head is selected as a comparison quantity. When the
energy equation (4.32) is divided by g and integrated, it gives the Ber-
noulli flow tube equation
where
All flow losses are included in the term /?/, which in a flow system consists of
two parts:
1. Friction resistance
2. Local resistance
4.I.5.2 Viscous Flow
When liquid flows along a solid surface (see Fig. 4.2) a shearing stress is
set uo (friction oower/surface). which is exoressed bv
