Bernoulli's Principle
Pressure, temperature and velocity govern how high geysers such as Old Faithful shoot water into the air.Copyright US Geological Survey http://gallery.usgs.gov/photos/161
Bernoulli's principle relates the pressure of a fluid to its elevation and its speed. Bernoulli's equation can be used to approximate these parameters in water, air or any fluid that has very low viscosity. Students use the associated activity to learn about the relationships between the components of the Bernoulli equation through real-life engineering examples and practice problems.
The Bernoulli principle has a wide range of applications in engineering fluid dynamics, from aerospace wing design to designing pipes for hydroelectric plants. For example, in the case of a hydroelectric plant that utilizes water flow from mountain reservoir, knowing the elevation change from the reservoir in the mountains to the plant in town helps engineers determine how fast the water will be flowing through the energy-generating turbines in the plant.
After this lesson, students should be able to:
- Calculate an unknown fluid condition (for example, fluid pressure, velocity, density or height) at one point along a flow streamline, if conditions are known at another point along the same streamline.
- Use the Bernoulli equation to explain that faster airflow causes a decrease in pressure, and give an example of a real-life application.