Design Portfolio: Water Rocket
Engineering Design Process Folio
1. Define the Problem
What need or want must be met by the solution?
Need to power a rocket using water
In the space provided, sketch three possible solutions to the given problem. Remember to be creative!
3. Research and Generating Ideas
Weight is the force generated on the rocket by the gravitational attraction of the earth
The amount of weight first depends on the mass of the rocket itself. Mass is a measure of the amount of matter or material an object contains.
A newton is the metric unit for force. One newton is the force required to accelerate a mass of one kilogram to one meter per second squared.
Thrust is a force that produces lift-off, or upward movement of a rocket. Thrust acts through the center of gravity and must exceed weight in order to move the rocket off of the launch pad.
The force of drag acts through the Center of Pressure (CP) of the rocket
It is important for a rocket to have and maintain stable flight. In order to maintain stable flight, rotation around all three axes - especially yaw and pitch - must be prevented.
to move the center of gravity towards the nose of the rocket, mass should be added to the nose
he way you can change the location of the center of pressure is by adding more material to the nose or tail of the rocket.
Active recovery systems tend to be better for heavier rockets, and provide a safer recovery. However, active recovery systems are often more complex, have a higher chance of failure, and add weight to the rocket.
- Weight is the force generated on the rocket by gravitational attraction of the earth
- Weight opposes thrust
- Weight pulls down through the center of gravity for a rocket
- A newton is the metric unit for force. One newton is the force required to accelerate a mass of one kilogram to one meter per second squared.
- Thrust is a force that produces lift-off, or a upward movement of the rocket
- Thrust must exceed weight to producer lift-off
Newton's Third Law of Motion
- For every action, there is an equal and opposite reaction.
- Rocket’s drag can be affected by the rocket's frontal area, shape, velocity, and air density.
- Velocity increases drag
- In order to maintain stable flight, rotation around all three axes - especially yaw and pitch - must be prevented
- To move the center of gravity towards the nose of the rocket, mass should be added to the nose.
- way you can change the location of the center of pressure is by adding more material to the nose or tail of the rocket
- recovery system is part of the rocket that allows the rocket to safely return to earth after launch
- parachute is an active recovery system
- he space inside of the nose cone tube may be too small. Look for items in the Recovery system work area called Deploy Volume and Tube Volume. If the tube volume (what you have actually designed) is less than the required deploy volume, then the parachute will not deploy. (Basically, the parachute is crammed into such a small space that it sometimes will not come out). If this happens, you should increase your actual tube volume by selecting a tube with a larger radius, or increasing the length of the tube.
- The mass of the ping pong ball may be too small. This is related to the issue described above in that the parachute needs to be pulled out of a small area. Adding clay to the ball will increase its mass and provide more force to pull the parachute out of the nose cone tube.
4. Identifying criteria and specifying constraints
2 liter Pepsi bottle
5. Exploring possibilities
Reflect on your brainstorm ideas and research notes. Generate any additional designs which you feel meet the criteria and constraints in the space below.
From the first to second I changed the fins because I made them weigh less and had more stability . I also changed the cone length to reduce drag.
This helped increase my static margin
I also figured out that my weight was reduced by putting my wings closer to the bottom
6. Selecting an Approach
a. Enter the constraints of the project in the first column.
b. Score each sketch for each constraint. + = 3 pts., √=2 pts., - = 1 pt. c. Total the columns and circle the highest score.
Sketch 1 Sketch 2 Sketch 3
Cost 3 2 2
Stability 2 3 1
Static margin 2 3 1
weight 2 3 2
Nose length 2 3 2
Total 11 14 8
7. Developing a Design Proposal
Take your highest scoring sketch and create working drawings (sketches with dimensions, so that you could build your project). Attach your working drawings to this sheet.
8. Making a model or prototype
In the space below, document (using digital pictures) your construction of the model/prototype. Be sure to include a picture of the final model/prototype.
9. Testing and Evaluating the Design, using specifications
As you create your solution, you will perform tests to make sure that the solution is meeting the needs of the given problem. If you solution does not work, you may need to repeat the previous steps of the Engineering Design Process, until you find a functional design. In the space below, document the type of test you conducted and the results.
10.Refining the Design
Based on your tests, propose refinements to the design and construction of the design problem in the space below.
We did not test more than once
11. Creating or Making It
If time allows, modify your model/prototype as proposed in refining the design. What additional steps would be necessary to produce this solution for mass market production? We did not test more than once and to mass produce we would require multiple
12.Communicating processes and results
Present your completed design portfolio as an oral presentation to the class.