Jet Propulsion
Introduction
Jet propulsion is one of many forms of motor control used in craft. Rocket design adds to the effective use of this method of propulsion through air. Some common materials used in the design of rockets are different metals, ceramics and plastics. These materials are used in different ways to give the rockets the desired shape or strength depending on the intended use.
RESOURCES: textbooks, videos, literature, pamphlets from Internet,
Field trip to local science exhibits.
Objective
Upon completing this project you will be able to:
- Demonstrate an understanding of various aerodynamic designs
- Design your own rocket
- Use hand tools, adhesives, and finishes to build a prototype of your design
- Describe the effects of jet propulsion
- Safely execute the procedure for releasing your jet propelled prototype
- Measure and calculate the height achieved
Challenge
Design a bottle rocket from either a 1 or 2-litre pop bottle. The design must utilize air pressure and water volume to maximize the height achieved. Design considerations include nose cone, tail fins and surface finish.
Parameters
The student must bring a 2-litre plastic pop bottle.
The design must leave the open end of the bottle exposed, as this provides the propulsion and must be attached to the launcher.
The design must provide some means of retrieval if the rocket does not fly straight up.
One of the finish materials provided in class must be used
The rockets must be finished by race day (no exceptions, no extensions).
Students must calculate height achieved by their rocket.
Exploration of Ideas
Mindmap, as a class, and discuss the various design solutions.
Each student must record their own design solutions
Suggest research in library and internet
Drawing of solutions required to be handed in with calculations of height
Alternate Solutions
Two separate design solutions are required from each group.
Discuss with students the best solution of the two.
After test day discuss ways to improve the designs
Selected Solution
Have the students draw a final sketch to follow during construction of their prototype.
Record all changes made during construction onto the final sketches.
Realization
Short lectures may be required on:
- Effect of water/air ratio
- Effects of propulsion (how jet propulsion works)
- Shapes of various fins and nose cones for aerodynamics
- Trigonometry for measuring height
Demonstrations may be required for:
- Hand saws, chisels, planes, sanding
- Hack saws, bending of sheet metal
- Adhesives- carpenters glue, hot glue gun
- Finishes- varnish, paint, resins
Analysis and Evaluation
Hand out a self evaluation sheet to each student, prior to construction
The sheet should contain levels of achievement for: Design portfolio, production, function, and aesthetics
Assessment
Each student should receive a break down of the marking system with the assignment details.
Eg. Self evaluation 10%
Solutions function 25%
Use of tools and machinery 25%
Class participation 10%
Design package 20%
Height calculations 10%
Total 100%
