TITLE: "VERIFICATION OF MOMENTUM EQUATION THROUGH
IMPACT OF JET"
OBJECTIVES:
• To measure the force exerted by a jet on a fixed vane and to compare the
magnitude of this force with force obtained by theory.
• To verify momentum equation experimentally through Impact of Jet.
APPARATUS REQUIRED:
i. Impact of jet apparatus,
ii. Weights and
iii. Stopwatch.
THEORY:
The momentum equation based on Newton’s 2nd law of motion states that the algebraic
sum of external forces applied to control volume of fluid in any direction equal to the
rate of change of momentum in that direction.
The external forces include the component of the weight of the fluid and of the forces
exerted externally upon the boundary surface of control volume.
If a vertical water jet moving with velocity ‘V’ made to strike a target (Vane) which is
free, to move in vertical direction, force will be exerted on the target by the impact of
jet.
Applying momentum equation, force exerted by the jet on the vane, F is given by
F = kρQV
Where, Q= Discharge from the nozzle (Calculated by volumetric method)
k= coefficient of force on vane (depend on shape)
A= area of jet (nozzle)
V= Velocity of jet = (Q/A)
For flat plate, k=1
For hemispherical curved plate, k=2
For 120° vane, k= 1.5
For 45° vane, k=0.5
EXPERIMENTAL SETUP:
The set up primarily consists of a nozzle through which jet emerges vertically in such
a way that it may be conveniently observed through the transparent cylinder. It strikes
the target plate or disc positioned above it. An arrangement is made for the movement
of the plate under the action of the jet and also because of the weight placed on the
loading pan. A scale is provided to carry the plate to its original position i.e. as before
the jet strikes the plate. A collecting tank is utilized to find the actual discharge and
velocity through nozzle.
PROCEDURE:
1. The relevant dimensions as area of collecting tank and diameter of nozzle were
noted.
2. When jet was not running, the position of upper disc or plate were noted.
3. Water supply was admitted to the nozzle.
4. As the jet struck the disc, the disc moved upward, then the weights were placed
to bring back the upper disc to its original position.
5. At this position, the discharge was found and the weights placed above the disc
were noted.
6. The procedure was repeated for different values of flow rate by reducing the
water supply in steps.
OBSERVATION:
Diameter of nozzle (d) = 8*10-3 m
Density of water () = 1000 kg/m3
Area of collecting tank (At) = 0.3*0.3 m2 = 0.09 m2
Area of jet= 5.03*10-5 m2
S.N. 1. 2. 3
Height of water level(h) m 0.05 0.04 0.04
Time taken (t) sec 6.44 7.84 5.74
𝑨𝒕 ∗𝒉 6.98*10-4 6.27*10-4 4.59*10-4
Discharge (Q) = 𝒎𝟑 /𝒔
𝒕
𝑸
Jet velocity (V) = (𝑨𝒓𝒆𝒂 𝒐𝒇 𝒋𝒆𝒕 ) m/s 13.90 13.68 9.125
Mass placed (kg) 1.5 0.95 0.45
Force acting (Fact = mg) N 14.715 9.3195 4.4145
Theoretical force (Fth) = 𝒌𝑸𝑽 14.55 12.86 6.28
𝑭𝒕𝒉 −𝑭𝒂𝒄𝒕 1% 27.53% 29.70%
% error = ( ∗ 𝟏𝟎𝟎%)
𝑭𝒕𝒉
RESULT:
Forces acting on the jet were found to be 14.715 N, 9.3195 N and 4.4145 N.
CONCLUSION:
We calculated the experimental force operating on the jet from this experiment, and we
then compared it to the predicted force. We also conducted an experiment to confirm
the momentum equation. Several of the flaws found during the experiment might have
been caused by the student's negligence and the use of defective equipment.
PRECAUTIONS:
1. Apparatus should be in leveled condition.
2. Reading must be taken in steady conditions.
3. Discharge must be varied very gradually from a higher to smaller value.
TRIBHUVAN UNIVERSITY
INSTITUTE OF ENGINEERING
THAPATHALI CAMPUS
Lab report on LOSSES IN PIPE FITTING.
Submitted by: Submitted to:
Name: Bishal Kamali Mechanical Department
Roll no.: THA077BME016
Date : 2079/12/03
TITLE: LOSSES IN PIPE FITTING.
OBJECTIVES:
• To determine and estimate energy loss (major and minor losses) in fluid flow
through pipes.
• To determine the friction factor and coefficient of energy loss in bend, pipe
fittings.
APPARATUS REQUIRED:
iv. Pipe Fittings.
THEORY:
An energy balance in any flow system is given by Bernoulli’s equation:
𝑃1 𝑣21 𝑃2 𝑣22
+ + 𝑧1 = + + 𝑧2 +EF
𝛾 2𝑔 𝛾 2𝑔
Where,
EF = energy requirement (major and minor losses) (J/Kg)
𝑃1 , 𝑃2 = Pressure at point 1 & 2 (N/𝑚2 )
𝑣1 , 𝑣2 = Average flow velocity at point 1 & 2 (M/S)
g = Gravitational acceleration i.e. 9.81 m/𝑠 2
𝑧1, 𝑧2 = flow head (height) at point 1 & 2 (m)
Major losses: Major losses are associated with the frictional resistance of the fluid as
it flows through the pipe. This type of loss is also known as the Darcy-Weisbach friction
factor. The friction factor is influenced by the pipe diameter, fluid velocity, and
roughness of the pipe surface. Major losses are proportional to the length of the pipe,
and they are represented by the following equation:
𝑓𝑙𝑣 2 𝑓𝑙𝑄 2
hf = = 𝜋2𝑔𝑑5
2𝑔𝑑
2𝑔𝑑
i.e. f = (ℎ𝑓) , f = friction factor
𝑙𝑣 2
