Pitot Tube Setup

The Pitot Tube Setup is a fundamental experimental apparatus used in fluid mechanics laboratories to measure the velocity of fluid flow. It is widely used in mechanical, civil, and aeronautical engineering education to demonstrate the practical application of Bernoulli’s principle. The Pitot tube is one of the simplest and most accurate devices for point velocity measurement in pipes, ducts, and open channels.

In engineering institutes and research laboratories, the Pitot Tube Setup plays a vital role in understanding flow behavior, pressure variation, and velocity distribution. Due to its simplicity, reliability, and accuracy, it is also extensively used in real-world industrial and aerodynamic applications.

Principle of Pitot Tube Setup

The Pitot Tube Setup works on the principle of Bernoulli’s theorem, which states that for an incompressible, steady flow, the total energy per unit weight of fluid remains constant along a streamline.

When a Pitot tube is placed in a flowing fluid:

• One opening faces the flow and measures stagnation (total) pressure

• Another opening measures static pressure

The difference between stagnation pressure and static pressure is known as dynamic pressure, which is directly related to the velocity of the fluid.

Mathematical Relation

$$V = \sqrt{\frac{2 (P_t - P_s)}{\rho}}$$

Where:

• $V$ = Velocity of fluid

• $P_t$ = Total (stagnation) pressure

• $P_s$ = Static pressure

• $\rho$ = Density of fluid

This equation forms the basis for velocity calculation in a Pitot Tube Setup.

Construction of Pitot Tube Setup

A standard Pitot Tube Setup consists of the following main components:

1. Pitot Tube

A slender metallic tube with a small opening facing the flow direction. It is generally made of brass or stainless steel to ensure durability and corrosion resistance.

2. Static Pressure Port

Located perpendicular to the flow direction, this port measures static pressure without disturbing the flow.

3. Differential Manometer

Used to measure the pressure difference between stagnation pressure and static pressure. It is commonly filled with mercury or a suitable manometric fluid.

4. Flow Channel or Pipe

The Pitot tube is installed in a transparent or metallic pipe through which water or air flows.

5. Control Valve

Helps regulate the flow rate within the system.

6. Measuring Scale

Graduated scales are provided to accurately note manometer readings and calculate velocity.

The entire setup is mounted on a rigid frame for stability and ease of operation in laboratory conditions.

Working of Pitot Tube Setup

The working of the Pitot Tube Setup is straightforward and systematic:

1. The fluid is allowed to flow through the pipe or duct.

2. The Pitot tube is positioned facing the flow direction.

3. The front opening of the tube brings the fluid to rest, creating stagnation pressure.

4. Static pressure is measured through side openings.

5. The differential manometer shows the pressure difference.

6. Using Bernoulli’s equation, the velocity of the fluid is calculated.

7. Readings are taken at different flow rates to analyze velocity variation.

This experimental procedure helps students and researchers understand the relationship between pressure and velocity in fluid flow.

Applications of Pitot Tube Setup

The Pitot Tube Setup has extensive applications in both academic and industrial fields:

Educational Applications

• Fluid mechanics laboratories

• Mechanical engineering experiments

• Civil engineering hydraulics labs

• Demonstration of Bernoulli’s theorem

• Velocity measurement experiments

Industrial Applications

• Measurement of air velocity in ducts

• Flow analysis in pipelines

• Ventilation and HVAC systems

• Wind tunnel experiments

Aeronautical Applications

• Aircraft airspeed measurement

• Wind speed analysis

• Aerodynamic testing

Due to its versatility, the Pitot tube remains a preferred choice for velocity measurement across multiple domains.

Advantages of Pitot Tube Setup

The Pitot Tube Setup offers several advantages:

• Simple and compact design

• High accuracy for point velocity measurement

• Easy installation and operation

• Low maintenance requirements

• Cost-effective compared to advanced flow meters

• Suitable for both liquid and gas flow

• Reliable performance in laboratory conditions

These advantages make it an essential apparatus in engineering education and research.

Limitations of Pitot Tube Setup

Despite its benefits, the Pitot Tube Setup has certain limitations:

• Measures velocity at a single point only

• Accuracy depends on proper alignment with flow direction

• Not suitable for highly turbulent or unsteady flows

• Requires correction factors in some cases

However, for controlled laboratory experiments, these limitations are minimal and manageable.

Importance in Engineering Education

The Pitot Tube Setup is an integral part of engineering curricula because it bridges the gap between theory and practical application. Students gain hands-on experience in:

• Pressure measurement

• Velocity calculation

• Understanding fluid energy concepts

• Experimental data analysis

It enhances conceptual clarity and prepares students for real-world engineering challenges.

Quality and Reliability

A well-designed Pitot Tube Setup is manufactured using high-quality materials to ensure long service life and accurate results. Precision-finished components, leak-proof connections, and calibrated measuring instruments contribute to reliable performance.

Trusted suppliers ensure that the setup meets standard laboratory requirements and is suitable for continuous academic use.