Thursday, August 16, 2018

PITOT TUBE

August 16, 2018

                                                            EXPERIMENT
                                                            PITOT TUBE
 
1)      OBJECTIVE -: Study the impact and static pressure a fluids using Pitot tube set up. To find the point velocity at the center of the tube for different flow rates of water and calibrate the Pitot tube, Plot velocity profile cross the tube.

2)      INTRODUCTION-:

Pitot tube is a device which is widely used to measure the point velocity.one of the main reason for using Pitot tube is that it can be used with minimal disturbance to the flow .The Pitot tube measures only the point velocity while using Pitot tube we usually come cross an error of 1% less than 1% for range of Reynolds Number. The Pitot tube was invented by the French engineer Henri Pitot in early 18th century but was early modified by French scientist Henry Darcy. There are simple devices with no moving parts.

They can be used not only for measuring flow velocity in open channel but in closed conduits as well. While using Pitot tube calibrations are required because velocities profile can change with flow rate.
Pitot tube basically consist of two concentric tubes which are parallel arranged to  flow small holes are present on the outer tube to the flow direction into the annular space small opening is present on the inner tube, connected to the other side of manometer. At equilibrium no fluids motion is present. Let Pi be Impact pressure and Po is Static pressure. These two pressures are obtained from Pitot tube. Impact pressure is the pressure exerted by the fluid when tube is inserted in the flow stream, whereas Static pressure is the pressure exerted by the fluid on the side wall.
Delta (H) =Delta (P)/ (Density x g)
Delta (H) =Height difference of the columns in meters (m)
Density of liquid = CC4 kg/m3
g=acceleration due to gravity m/sec

3. PROCEDURE -:


       I.            Shut off all the forced ball valves.

    II.            Switch on the main power. By using control panel we can switch (on or off) the power instead of switch off the main power.

 III.            Observe the manometer tubes only two different phase must be present. If not then by adjusting the valves that is attached to the top of the manometer remove the third phase.

 IV.             Open the control valve, the water will fall down in the sump tank through divergent channel. The diverter flow will change the flow direction.

    V.            Take a stop watch, for 15 second change the flow direction. Now water will collect in the measuring tank. By doing calibration, find all calculation.

RESULTS AND DISCUSSION -:

Table 1 measurement of tank, assumption

Density of ccl4 =               kg/cm3
Velocity = Volumetric flow rate/area
Area of measuring tank = L*B    (cm2) =
1cm =710 ml
Assumption =   v2    = 0