16
1 Fundamental Concepts of Fluid Mechanics for Mine Ventilation
a)
b)
Fig. 1.9 Velocity profile of the fluid circulating through a duct: a Laminar, b turbulent
Fig. 1.10 Speed profile of a
fluid moving on a surface
and boundary layer
v
L
δ
In a like manner, when a fluid flows on a plate, minimum velocity is reached in
contact with the plate. Then, the speed increases with distance from the plate up to
a point at which it remains constant (Fig. 1.10).
The Reynolds number is a dimensionless number, whose square root is inversely
proportional to the distance from a surface at which the liquid velocity remains
constant (δ) (boundary layer) (Fig. 1.10). This number arises from the relationship
between inertial (destabilizing) and viscous (stabilizing) forces acting on the fluid
6
and is, therefore, dimensionless. Thus:
6 Dimensionless numbers have proven very useful in scaling-up operations. That is to say, in
quantifying the expected results on a real scale from those derived from tests on a smaller scale.
1 Fundamental Concepts of Fluid Mechanics for Mine Ventilation
a)
b)
Fig. 1.9 Velocity profile of the fluid circulating through a duct: a Laminar, b turbulent
Fig. 1.10 Speed profile of a
fluid moving on a surface
and boundary layer
v
L
δ
In a like manner, when a fluid flows on a plate, minimum velocity is reached in
contact with the plate. Then, the speed increases with distance from the plate up to
a point at which it remains constant (Fig. 1.10).
The Reynolds number is a dimensionless number, whose square root is inversely
proportional to the distance from a surface at which the liquid velocity remains
constant (δ) (boundary layer) (Fig. 1.10). This number arises from the relationship
between inertial (destabilizing) and viscous (stabilizing) forces acting on the fluid
6
and is, therefore, dimensionless. Thus:
6 Dimensionless numbers have proven very useful in scaling-up operations. That is to say, in
quantifying the expected results on a real scale from those derived from tests on a smaller scale.