CONTINUITY EQUATION
Fluid Flow
Continuity Equation Summary
•
Density changes in a fluid are inversely proportional to temperature changes.
•
Buoyancy is the tendency of a body to float or rise when submerged in a
fluid.
•
The pressure exerted by a column of water is directly proportional to the
height of the column and the density of the water.
P =
r h g
gc
•
Pascal’s law states that pressure applied to a confined fluid is transmitted
undiminished throughout the confining vessel of a system.
•
Volumetric flow rate is the volume of fluid per unit time passing a point in
a fluid system.
•
Mass flow rate is the mass of fluid per unit time passing a point in a fluid
system.
•
The volumetric flow rate is calculated by the product of the average fluid
velocity and the cross-sectional area for flow.
V
A v
•
The mass flow rate is calculated by the product of the volumetric flow rate
and the fluid density.
m
r A v
•
The principle of conservation of mass states that all mass flow rates into a
control volume are equal to all mass flow rates out of the control volume
plus the rate of change of mass within the control volume.
•
For a control volume with a single inlet and outlet, the continuity equation
can be expressed as follows:
minlet
moutlet
•
For a control volume with multiple inlets and outlets, the continuity
equation is:
minlets
moutlets
HT-03
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