Teaching the Concept of Bernoulli Equation Using Particle Image Velocimetry (PIV)

Particle Image Velocimetry (PIV), a state-of-the-art flow visualization technique, is used in this paper to demonstrate the concept of the Bernoulli equation which is one the oldest and most widely used equations in fluid mechanics. The experiment is based on the venturi effect to permit application of the Bernoulli equation to a laboratory scale test facility. The experimental set-up consists of a horizontal, straight transparent pipe with a venturi tube (contraction and expansion of the pipe diameter). Both water and air pipe flows are characterized. Students are required to measure and predict the average velocities and pressure upstream and downstream of the expansion region, using combined Bernoulli and Continuity equations. The averaged velocities are obtained using a flowmeter and compared with their corresponding two dimensional velocity distribution measured by the PIV system. Pressure difference over the expansion is measured using wall mounted static pressure taps and compared with predicted quantities. The paper includes the cost of the experimental setup and various teaching strategies.