Pitot Tube(velocity Profile)

PITOT TUBE’S EXPERIMENT

GROUP IV (BATCH –I) Manne Venkata Harish Babu ME08B013 Manoj Kumar Tripathi ME08B014 Medarametla Krishnakalyan ME08B015 Mohammad Salimuddin ME08B016

AIM : To determine the velocity profile of air flowing through a pipe using Pitot’s tube

BACKGROUND: The Pitot’s tube is widely employed to measure fluid velocities in flowing fluids  One of the major reasons for this is that it can be used with “minimal disturbance” to the flow 

Continued… In measurement system terminology, the sensor is the Pitot tube itself.  The measurand (velocity) is converted to a differential pressure, which is then converted by an intermediate modifying device (manometer) to a differential height of manometer fluid that is read from a calibrated scale 

Construction of Pitot tube:

THEORY: Pitot Tube is aligned with the flow direction  Assuming an inviscid, incompressible flow 

V a Pstag Pstat

– velocity of air – density of air – total pressure – static pressure

Continued.. 

1 2 ρav 2

Now, this , the dynamic pressure is converted into differential height of the fluid( water, in our case) of manometer, hence

1 2 ρav  ρwgh 2

Experimental Set-up: A

2 inch diameter GI pipe was connected to a 1 inch diameter GI pipe via an expansion joint, to increase the resolution and accuracy of the readings.

Continued…  Pitot

tube was attached to a U-tube filled with water(manometer)

 The experiment was done at a pressure

of 10 kgf/cm2

Complete set-up:

Reading Evidence (Video):

Observation : S.No.

Distance from the centre Height difference x, (cm) h , (cm)

Velocity , V (m/s)

1.

-2.5

0.65

10.3

2.

-2.0

1.95

17.84

3.

-1.5

2.9

21.76

4.

-1.0

3.6

24.24

5.

-0.5

4.2

26.19

6.

0

4.5

27.11

7.

0.5

4.15

26.03

8.

1.0

3.55

24.07

9.

1.5

2.9

21.76

10.

2.0

1.9

17.61

11.

2.5

0.7

10.69

Velocity Profile: Velocity,V(m/s) 30

25

20

15

Velocity, V(m/s)

10

5

0 -3

-2

-1

0

1

2

3

Result : 

The velocity profile of air flowing through the given tube, is almost parabolic.

Sources of error: Misalignment of the tube axis and the velocity vector , exposing the static taps to some component of the velocity  Influence of the hole-tip spacing  Wall effect 

THANK YOU