EXPERIMENT
BERNOULII
SET-UP
1. OBJECTIVE
To verify experimentally
the validity of Bernoulli’s equation for fluid flow.
2. INTRODUCTION
Bernoulli’s Principle is
a physical principle formulated that states ‘as the speed of moving fluid
(liquid or gas) increases, the pressure within the fluid decreases Bernoulli’s
Principles is named after the Swiss scientist Daniel Bernoulli .Bernoulli’s
Principle is demonstrated by the Bernoulli Equation .It is relation between
pressure, velocity and elevation Bernoulli’s Law can be explained in terms of
the law of conservation of energy. The converging diverging nozzle is used to
show the validity of Bernoulli’s Equation.
Kinetic energy +potential
energy+ flow energy =constant
Assumptions made in deriving the Bernoulli’s equation are-
Assumptions made in deriving the Bernoulli’s equation are-
1. Fluid is
incompressible (density ρ, is constant)
Then it is expressed with the following equation-
Then it is expressed with the following equation-
Where the SI units
ρ =density of the flowing
fluid in ‘kg/m’
g=acceleration due to
gravity in ‘m/s2’
v=mean velocity of the
fluid flow at the cross section in ‘m/s’
z=elevation head of the
center of the cross section with respect to a datum z=0
h= total
(stagnation) head in m
3.
PROCEDURE-
1. Check if the drain
wall is open and keep it wide open and check whether the outlet pipe goes to
the drain. Initiate the flow through the venture test section by opening the
inlet valve.
2. Check all the
manometer tubing are properly connected to the corresponding pressure tap and
our air bubble free. If needed flush the air bubbles by slowly closing the exit
valve.
3. Adjust the both
inlet and outlet valve so that you get the maximum difference in level between
the tapping point #7 and #8.
4. Wait for some time
for the level in manometer tube to stabilize (it takes sometime steady state to
reach).
5. After the steady
state is achieved, redirect the water outlet loose into a container whose
capacity is known (10 Lt for example) and record the time taken for the water
to fill it up.
6. Gently push the tube
connected to the manometer so that is end reaches the cross section of the
venturi tube for, example, Wait for some time to note the down the readings
from the manometer. The reading shown by the manometer is the sum of the
velocity and pressure head that is total head because the Pitot tube is held
against the flow of the fluid forcing it to stop. The reading in the manometer
measures just the pressure head because it is connected to the venturi tube
pressure tap which does not obstruct the flow thus measuring the flow of the
static flow.
7. Repeat step 6 for
the other cross section (3,5,7 for example)
