report Practice Works Demonstration theorem Bernoulli.3éme year civil.module hydraulic engineering

Demonstration of Bernoulli

Aim of work :

     This is the study of the conversion of potential energy into specific specific kinetic energy and vice versa in accordance with the Bernoulli equation in terms of uniform flow and a flow varies gradually 
·     Graph of a hydraulic grade line and load line current from the experimental data Construction 
·     Calculation of losses between sections

      Summarizes the theory:
      Bernoulli's equation which represents the conservation of the total mechanical energy to an incompressible fluid results in the relation:

Or: P is the static pressure in the considered point 
         V: is the average velocity of the point in question given by the relation

Qv is the volume flow rate which represents the amount of liquid passing through the section per unit time.

In a horizontal tube: Z1 = Z2 Bernoulli's equation becomes :

Therefore relation Bernoulli translated conservation of the total hydraulic load

Description of the experimental setup:

The bench includes a vein powered test closed circuit by a pump 
The test section includes: 
· A entonnement 
· A venturi 
· A cylindrical part 
· A catcher 
· Different pressure taps with piezometric tubes 
· A pitot tube

The dimensions of the tube:

Position	manometric	diameter (mm)
A	h1	25.0
B	h2	13.9
C	h3	11 .8
D	h4	10.7
E	h5	10.0
F	h6	25.0

     Experimental procedure:

Using the adjustable feet horizontally adjust the camera on the hydraulic ban. Gently fill multiple gauge carefully removing air bubbles, ensure that there is no air bubbles in pipes made pressure .
By adjusting the water flow coming from the valve and adjusts the output level in the manometer .
The final adjustment is done with the standard bicycle pump which adjusts the air pressure above the water column .
Measure the flow of water with the volumetric method : that is to say, we measure with a stopwatch the time of filling a quantity measure using the scale located at tank mounted in front.
                                                                    V = Q / T
Or V : the volume of water is measured by the scale located on the front wall of tank
        T: is the measured time
Meet the piezometric heights of the different sections was using piezometers .
Push the probe total pressure ( pitot tube ) in the test section . Rate readings Pitot sections 1 to 6.
Results and calculations:

Complete the table with the results of measurement and calculation . Construct the piezometric line and the load . What are your comments on the agreement between the theoretical total pressure and the pressure measured by the probe ( pitot tube )
Volume collected in m3 V1=10L and V2=15L
Charging time in s T1=142 and T2=227
The flow is :  Q1= 7.04  m³/s and Q2=6.63 m³/s 
table

i  piezometers	Diameter sections D (mm)	Areas of the sections A (mm)	piezometric head h=P/pg	speed  average  V=Q/T	dynamic height  V^2/2g	total load H
1	25.0	490.9E-6	273	1.350	0.092	0.365
2	13.9	151.7E-6	260	4.370	0.973	1.233
3	11.8	109.4	253	6.060	1.871	0.253
4	10.7	89.9	242	7..374	2.771	0.242
5	10.0	78.5	233	8.445	3.634	0.233
6	25.0	490.9

Conclusion :

The study on Bernoulli's done in this lab allows us to verify its validity, and we can see from the graph that we achieve almost equal total energies but full equality can not be achieved in practice due records errors when handling.