Rationale- Technical students will need to know fluid power calculations to determine the appropriate size hydraulic components to use in a real-world circuit. All students will benefit from real-world application of surface area and volume calculations.

surface area, volume, pressure, work, displacement, force, radius, diameter, pi.

Given dimensions of a hydraulic circuit, the student will be able to calculate the forces, and vice-versa.

The duration of the lesson can be adjusted as needed, but two hours for demonstration, discussion, and lab is adequate.

An assortment of plastic syringes, plastic “fish tank” tubing and T-connectors are required.   A bucket of water or sink.

Suggested
Instructional Strategies Higher Order thinking: Application

W -  Students will need to know this concept in
order to create their own hydraulic system.

H – There is an
enjoyable hands-on demonstration where students use plastic syringes and tubing
to create hydraulic (water-filled) circuits.  

E  - Students will write their reflections in
their Engineering Notebooks.

R  - Students will express their understanding
by creating a working hydraulic system capable of lifting several textbooks
using minimal input force. 

T – Students may be
paired to match strengths with weaknesses.

O – The manipulative
for conceptual understanding will naturally progress to the instructor-directed
demonstration of calculation of force, thus proceeding forward to students
creating their own circuits capable of lifting a heavy load of textbooks.  This can become a competition between teams
as to who can lift the most books using the least input force.  

Instructional
Procedures  -     An instructor-made hydraulic system will be presented to the class.   This circuit will be designed so that sitting two textbooks (or similar weights) on the input cylinder will lift three or more textbooks on the output cylinder.      

Review of order of operations, substitution, solving equations, area of a circle, and volume of a cylinder.

Pascal’ law will be explained and demonstrated along with fluid power calculations.

Students will calculate force, area, and volume for teacher-made examples.

Students will create their own hydraulic circuits capable of lifting a stack of textbooks using
significantly less input force.

Extension – KhanAcademy.org – fluids.

Formative Assessment

Students will check and correct their mathematical calculations and realize success in constructing
their own hydraulic circuit.

Related Materials and Resources –

https://www.grc.nasa.gov/WWW/k-12/WindTunnel/Activities/Pascals_principle.html

surface area, volume, pressure

Author - R. Abbott, B. May, R. Sealover

January 14, 2013