Published: Aug-2026 | Category: Fun With Science
How can an aircraft weighing hundreds of tonnes rise into the sky?
The answer begins with something we cannot see: moving air. Air has mass and exerts pressure, and when engineers control how it moves around a surface, it can produce powerful aerodynamic forces.
In this practical physics investigation, students use a model aircraft wing and a Data Harvest Wireless Differential Gas Pressure Sensor to compare the pressure above and below the wing. By changing the angle of attack, they can investigate how the pressure difference changes and explore what happens as the wing approaches a stall.
Watch the Bernoulli’s Principle experiment on YouTube
Bernoulli’s principle describes a relationship between the speed and pressure of a moving fluid. In this context, the word fluid includes both liquids and gases, so the principle can be applied to moving air.
Under suitable flow conditions, an increase in the speed of a fluid is associated with a decrease in its static pressure. This helps us understand why different airflow conditions around an aircraft wing can create a pressure difference.
An aircraft wing influences both the speed and direction of the surrounding air. Its shape and angle create different pressure conditions above and below the wing. The resulting pressure distribution, together with the wing changing the momentum of the air, produces an aerodynamic force.
Part of this force acts upwards and is known as lift.
In this experiment, a model aircraft wing is placed in a stream of air produced by a leaf blower. The wing remains stationary while the air moves around it, simulating the relative airflow experienced by an aircraft moving forwards.
Small pressure points on the upper and lower surfaces of the wing are connected to the two ports of a Wireless Differential Gas Pressure Sensor.
Rather than measuring each pressure independently, the sensor measures the difference between them. This makes it possible to see how the pressure distribution around the wing changes as airflow is introduced and the angle of attack is adjusted.
The angle of attack is the angle between the wing and the direction of the incoming airflow.
At a small angle, air can flow relatively smoothly around the wing. As the angle of attack increases, the wing changes the airflow more strongly and the pressure difference will generally increase.
However, this increase does not continue indefinitely. If the angle becomes too large, the airflow may no longer follow the upper surface smoothly. It begins to separate from the wing, producing a turbulent wake and changing the pressure distribution.
This is associated with a reduction in lifting performance and is known as an aerodynamic stall.
Pressure differences around a wing cannot normally be seen directly. Students may observe the movement of a model wing, but this does not reveal what is happening to the air pressure at its surfaces.
Using a Differential Pressure Sensor turns this invisible effect into measurable data. Students can watch the pressure difference respond as the airflow begins, stabilises and changes with the wing angle.
This creates a clear connection between an abstract physics principle, a practical measurement and a familiar real-world application.
This investigation allows students to:
Begin by securely mounting the model wing in front of the airflow source. Connect one pressure tube to the pressure point on the upper surface of the wing and the second tube to the pressure point on the lower surface.
Attach the other ends of the tubes to the corresponding ports on the Differential Pressure Sensor. Check that the tubing is secure, unkinked and not obstructed.
Connect the sensor to EasySense using Bluetooth or USB and zero the pressure reading before starting the airflow.
Set the wing to its first angle of attack and begin recording. Switch on the airflow and allow the pressure measurement to settle before recording the result.
Increase the angle of attack by a consistent amount and repeat the measurement. Continue across a suitable range of angles, while keeping the airflow source, distance and power setting unchanged.
The results can then be displayed as a graph of pressure difference against angle of attack.
When air begins to flow around the wing, the sensor should detect a difference between the pressure at the upper and lower surfaces.
At smaller angles of attack, the airflow follows the wing relatively smoothly. Increasing the angle will generally change the pressure distribution and increase the aerodynamic effect of the wing.
At higher angles, the results may stop following this trend. If the airflow separates from the upper surface, the pressure difference may level off, fluctuate or decrease. The precise result will depend on the wing design, airflow speed, position of the pressure points and quality of the airflow.
Students can use the data to identify:
A stall does not mean that an aircraft’s engine has stopped. It is an aerodynamic condition caused when a wing exceeds its critical angle of attack.
At excessive angles, the airflow can no longer remain smoothly attached to the upper surface. The separated and turbulent airflow changes the pressure distribution and reduces the wing’s ability to generate lift.
This experiment demonstrates why simply increasing the wing angle cannot produce more lift forever. Aircraft designers and pilots must carefully consider the relationship between airspeed, wing shape and angle of attack.
Using the Wireless Differential Gas Pressure Sensor with EasySense allows students to observe small pressure changes in real time.
Rather than relying only on a visual demonstration, students can collect quantitative evidence and use it to test their predictions. They can compare readings at different angles, repeat measurements and identify patterns in the resulting graph.
This supports practical data-handling skills, including:
Bernoulli’s principle and related pressure effects are used in many technologies beyond aircraft.
Racing cars use aerodynamic surfaces to generate downforce rather than upward lift. This pushes the tyres more firmly against the track, improving grip and allowing the vehicle to corner at higher speeds.
In an atomiser, rapidly moving air creates a pressure difference that helps draw liquid into the airflow. The liquid is then broken into small droplets and released as a spray.
Traditional petrol engines used a carburettor containing a narrow section called a Venturi. Air accelerated through this section, creating a pressure difference that helped draw fuel into the airflow before combustion.
In medical equipment, a Venturi mask uses a fast-moving flow of oxygen to draw in a controlled amount of surrounding air. This allows a predictable oxygen concentration to be delivered to a patient.
Once students have completed the basic investigation, they can extend it by changing one variable at a time.
The Bernoulli’s Principle investigation is available through Data Harvest’s Practical Explorer collection of free science activities.
Explore Practical Explorer and download the free worksheet
The Data Harvest Wireless Differential Gas Pressure Sensor is designed to measure small changes in gas pressure with high precision. Its two pressure ports allow students to compare pressure at two different points, making it ideal for investigating Bernoulli’s principle and other pressure-related phenomena.
The sensor offers Bluetooth and USB connectivity, independent logging and real-time data collection using EasySense. It can also be used for investigations involving gas compression, respiration, transpiration, pressure with depth and gas laws.
Learn more about the Wireless Differential Gas Pressure Sensor
This Bernoulli’s Principle experiment provides a practical and measurable way to investigate the physics behind flight.
By comparing the pressure above and below a model aircraft wing, students can observe how angle of attack affects the pressure distribution and explore what happens when the airflow begins to separate.
The investigation combines aerodynamics, pressure, forces and data analysis while connecting classroom physics to aircraft, racing cars, engines, medical equipment and familiar everyday devices.
Although air is invisible, its effects can be measured. With the Wireless Differential Gas Pressure Sensor and EasySense, students can turn those invisible pressure changes into clear data and discover the forces that help make flight possible.
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