Mechanical Energy Balance: Summary
The answers to the ConcepTests are given below and will open in a separate window.
Key points from this module:
- The mechanical energy balance assumes an incompressible fluid and steady-state flow.
- An increase in fluid velocity corresponds to a decrease in the sum of the static pressure, potential energy and internal energy.
- For a fluid flowing horizontally, when the velocity increases, the pressure decreases.
- The Bernoulli equation is used when the there are no frictional losses and no shaft work.
- A Pitot tube can be used to measure fluid velocity by using the Bernoulli equation.
From studying this module, you should now be able to:
- Apply Bernoulli’s equations to determine flow rates.
- Know where to apply Bernoulli’s Equation in a system.
- Make assumptions based on the physical nature of the problem.
- Use Bernoulli’s equation to find velocity, pressure, and/or height at any point in the system.
- Use the continuity equation in conjunction with Bernoulli’s equation to relate two velocities.
Bernoulli Pressure Lowering – Visual representation of pressure drop due constriction in a tube- friction is also taken into account.
Prepared by John L. Falconer, Department of Chemical and Biological Engineering, University of Colorado Boulder