Faculty of Engineering
School of Chemical & Petroleum Engineering
Chemical Engineering department
EXPERIMENT NUMBER FIVE
STATIC & DYNAMIC PRESSURE
Instructor: Mr. Ali & Miss. Hawzheen
Author Name: Aree Salah Tahir
Experiment Contacted on: 19/Nov/2013
Report Submitted on: 26/Nov /2013
The aim of this experiment:
The aim of this experiment is to find the dynamic
pressure in a moving fluid using piezometer and pitot
tube. By calculating its static pressure and its total
When a fluid is in motion it’s affected by two types of
pressure which are dynamic and static pressure. Static
pressure is the pressure in still liquids and in this
experiment it’s used to calculate the dynamic pressure
in moving fluids, for finding the static pressure we use
Dynamic pressure (velocity pressure) is the kinetic
energy per unit volume of a fluid particle, it’s the
difference between the total pressure (also called
stagnation pressure) and
To find the dynamic pressure we have to find two
other pressures at first, which are static and the
total pressure because the total pressure is the sum
of both dynamic and static pressure, thus dynamic
pressure is the difference between the total and the
Prandtl’s tube is a sort of combination of both the
piezometer and the pitot tube which are for finding
the static and dynamic pressures in a moving fluid.
Pdyn. =1/2 PV2
The dynamic pressure is also called velocity
pressure, the dynamic pressure rises with square of
the flow speed.
In fluid dynamics, Stagnation pressure (total
pressure) is equal to the sum of the free-stream
dynamic pressure and free-stream
𝑃 𝑑𝑦𝑛/𝛾 =𝑃𝑡/𝛾−𝑃𝑠/𝛾
Before the actual measurement the manometer
must be prepared and vented;
1. Connect the outputs of the prandtl’s tube by the
connecting hoses to the dual water manometer.
2. Close all cocks of the pipe system, and the vent
valves on the water manometer.
3. Switch on the pump and open the pipe system
4. Open the lower vent valves of the water
The pipe section and connecting hoses are vented
by the water flow.
When there are no longer air bubbles in the
connecting hoses, close the lower vent valve
simultaneously, then close the inlet cock and open
the drain cock.
Performing the experiment:
Carefully open the upper vent valve and inlet
cock, observing the water
level: No water should emerge from the upper vent
Read of the two heads of water Pt and Ps.
High pressures can be adjusted by means of the
inlet. If lower pressures
are to be measured, reduce the inlet cock and
adjust the head of the water with the drain cock.
twin tube manometers,1:
digital pressure display,3:
supply tank with submersible pump,:5
differential pressure manometer,:7
hydrostatic pressure in liquids,:9
Bourdon tube manometer,:12
As the velocity increases all of dynamic, static and total
pressure increases but for dynamic pressure it increases
with square of the flow velocity.