MODULE 2
VELOCITY STREAKLINES
·
Langarian view-point Canalytical) ↳ difficult to construct
↳ considers the individual fluid particle all the time .
a streamline of a real
Velocity is obtained by differentiating the particle's flow since individual
position vector with respect to time . Motion fluid particles are not visible to
of
entire flow field = solve momentum naked
equation eye
for each particle ↳ injecting dye into flow is a simple method
↳ Applied in varefied gas
dynamics to obtain streamline information
Fulerian approach (experimental) ↳
dye will trace out a path known
·
as a
↳ focus on a certain point in space' consider "streakline" which can be photographed
the motion of fluid particles that pass that
point as time
goes on VORTEX
Most * ↳ flow for which streamlines
↳
applied approach
are concentric circles with
FLOW VISUALISATION a well-defined core
It's useful to construct lines in flow fluid to
indicate speed3 direction Not to be confused with rotational flow
*
Which is circular motion of fluid particles
No internal Without a distinct vortex structure
friction
↳
viscosity FLOW PARAMETERS
·
Velocity :
V(s , t) ; S =
position along streamline
↳ Ideal fluid t =
time
·
Discharge : Q(V t) ; , volume per second passing
Friction at a given point
wall surface ·
Pressure (P pgh)
=
or depth leg .
river or channel)
FLOW CLASSIFICATION
↳ Real fluid ↳ characterised Two classes TIME DISTANCE
by :
· Time :
Steady ->
parameters decribing flow do not
STREAMLINES change with time
parameters do
↳ a live representing the Unsteady -
change with time
direction of flow of a series
·
Distance : Uniform - -
parameters decribing flow do not
of particles at a given vary with distance along a flow path
instant Non-uniform o parameters vary from point
-
flow path
↳Streamlines are
tangential to the
velocity rectors to point along a
of the fluid particles :: there is not flow
across the streamline . >
Flow between
-
parallel plates
STREAMTUBES Uniform
-
↳ a set of streamlines
arranged in the form of an
Converging flow
-
imaginary pipe/tube Non-uniform
-