let’s discuss representation of stream lines.
when we talk about stream lines, these are,
hypothetical lines, which represents, fluid
flow.
about stream lines we can write down few facts,
by studying, we’ll understand that, how
stream lines gives us the whole idea of flow
of fluid.
so the very 1st point we can write of which
i have already given you a hint that, stream
lines, in a flowing fluid, are the representation
of, fluid particles motion.
another point we can write, for a flowing
fluid, direction of, flow velocity of fluid
particles, is given by, the direction of,
stream lines and, speed of, fluid flow, is
measured by, the density of, stream lines.
now, another important fact about stream lines
we can write, like what we have just written,
that direction is, given by stream lines,
and speed is measured by the density of stream
lines.
so we can write, in a region, where, flow
velocity is more, this implies we can say,
lines or streamlines are, denser. or these
are closed to each other.
and in a region, where flow velocity is less,
this implies we can simply state, stream lines
are, rarer. in this situation if we just talk
about, the flow of a fluid, in stream line
manner or, in a straight line.
say we are given with a fluid, flowing on
a horizontal surface, say it is horizontal
ground.
if we compare the flow of an ideal fluid,
or a real fluid on ground, we can say an ideal
fluid, if it is flowing, then we can state,
an ideal fluid, flow is stream line as well
as we can say, there is no viscosity, there
is no, other characteristics of a real fluid.
so we can say, everywhere the fluid particle
velocity is same, so we can say, we draw stream
lines in this manner, that all these are equidistant
from each other.
and, as fluid is flowing with the same velocity
everywhere, the density of stream line is
same. and similarly if we draw the situation
for a real fluid, we can say in case of a
real fluid on ground, the density of stream
line is less because on ground due to the
overall weight of fluid, viscosity is more.
so, fluid layer which are in contact with
the ground will flow relatively with a lesser
speed and, the fluid layer which is at the
top will flow with more speed.
so this is the way how stream lines are drawn,
at the top, stream lines are quite close.
and as we move from top to bottom, the density
between stream lines is less.
here the stream lines are seperated apart,
and at the top we can say stream lines are
quite close to each other.
this shows that if there is a point a, and
there is a point b, we can state flow velocity
at ay is more than the flow velocity at b.
this is the way how, stream lines gives us
the idea about, the flow velocity of fluid.
