Final Project Link

https://docs.google.com/file/d/0B5aMGSDZFK2kMFlhT3FVTi1oTnc/edit?pli=1

Heres the stuff

Fins:

To make and design the fins for our rocket I used the NASA simulator. I found out that we would get the best fins if we made them out of cardboard. I also found out that the cardboard shouldn’t be too thick or it would increase the air resistance. I also discovered that the fins should be trapezoidal so that they stick out of the rocket to give it maximum stability, it would increase air resistance a little but that was ok because we traded that for stability and height. There were other detentions that I tweaked to help the rocket go a little higher but they didn’t help that much.

Summary:

I thought that overall our rocket was great. I am glad and surprised that we won the hang time competition and I think we had a great rocket. I’m surprised that our rocket won. It didn’t go higher than Aaron and Oliver’s but the parachute actually deployed. I know that if Aaron and Oliver’s parachute worked than we would have lost.

I think that we could have improved our rockets a little bit. We could have made the nose cone better so that we could fit the parachute but it still worked. Overall if we had more time we could have made our rocket a lot better. I’m still glad we won though.

Winners

We Won !!!!!!!!!!!!  With 5.88s we had the longest hang time.  It was the first time we got our parachute to deploy 

We Won !!!!!!!!!!!!

We Won !!!!!!!!!!!!

We Won !!!!!!!!!!!!

We Won !!!!!!!!!!!!

We Won !!!!!!!!!!!!

We Won !!!!!!!!!!!!

final

Homework for Final

Jay- Write about the parachute (1-2) paragraphs.  Write a reflection about our project  (1-2) paragraphs.

Brett- Write about the fins (1-2) paragraphs.  Write a reflection about our project  (1-2) paragraphs.

Charley- Do the rest and put it together

Post paragraphs on the blog by Thursday night.

Parachute

We were planning on either using a circular, or rectangular nose cone.  We had great difficulty trying to make the circular chute.  The rectangular one was too large  and it would not deploy.  So we are using our parachute that is a half circle.  We don't think think that the shape will matter much, as long as it falls properly, deploys, and has a large surface area.

Nose Cone

We are no longer using a conical nose cone.  We suspect that are simulator results were too sensitive to weight.  Our colleagues results show that a parabolic nose cone reduces drag the nose.  We are using a parabolic nose cone.

Fin Results

Blueprint

1 square = 2 cm

There are 3 fins, equidistant apart

Reasoning

      We used the simulator to find the best fins and nose cone.  We also realized that 3 fins would work the best for our rocket.  We added the two pieces of duck-tape to help secure our pressure chamber.  We only used two pieces of tape because we want the rocket to be as light as possible.  We are putting the parachute inside the cone so the center of mass will be higher up and in a better place.  We used an elliptical cone because our results from the simulator showed that it was the best to use.  On the internet, we learned that rockets going at sub-sonic speeds should have a rounded tip.  This is why we put a marble at the tip of our nose cone.  We made the cone out of a circular piece of cardboard because we thought that it would be most efficient, making it aerodynamic and light.  Our simulator results showed that it is very important that the nose cone is light.  We chose the Smart Water bottle, because it is smooth, long and thin, making it aerodynamic.

Document/Summarize today's step in the design process - Design & Construction


We thoroughly tested using the simulator.  We figured out what kind of cone and fins we are going to use.  We cut out the cones and taped around our pressure chamber.

My Cone Results

Conical
Length=2cm
Diameter=8cm

I got a 1L Smart Water bottle and a Fruition bottle from Giant Eagle (I couldn't find a picture).

Here is my Data Sheet:

Flight One

Body:

Payload Height (cm): ____7_____

Nozzle Radius (cm): ____1_____

Fairing: Yes

Fairing radius (cm): ___.606  oz/in3 (1.98)__

Nose Cone:

Shape: __parabolic______

Material: _1/16 hollow cardboard_

Propulsion:

Water (liters): _ 50____

Pressure (KPa): __ 70___

Fin Design:

Fin Height: _5__

Fin Shape: _trapezoidal____

Number of Fins: _4___

Fin Dimensions:  w=3.5, L.E. Ang=44, T.E. Ang= 29

Launch Stats:

Max Altitude (m): __28_

Max Velocity (m/s): __42_

Flight Two

Body:

Payload Height (cm): ____10_____

Nozzle Radius (cm): ___1.5____

Fairing: Yes

Fairing radius (cm): __(3.79/2)___

Nose Cone:

Shape: ____spherical___

Material: ___solid plastic________

Propulsion:

Water (liters):  71.185___

Pressure (KPa): __ 78.302

Fin Design:

Fin Height: __8__

Fin Shape: _trapezoidal____

Number of Fins: _3___

Fin Dimensions: w=3, L.E. Ang=53, T.E. Ang 50

Launch Stats:

Max Altitude (m): __9___

Max Velocity (m/s): __30___

Here is my spreadsheet data. I think I did something wrong though because both of my launches were kind of low.

Flight One	Flight Two
Body: Payload Height (cm): 0 Nozzle Radius (cm): .317 Fairing: Yes Fairing radius (cm): 2 Nose Cone: Shape: conical Material: solid plastic Propulsion: Water (liters): .3 Pressure (KPa): 200 Fin Design: Fin Height: 2.0 Fin Shape: trapezoidal Number of Fins: 3 Fin Dimensions:12cm, 12cm	Body: Payload Height (cm): 0 Nozzle Radius (cm): .5 Fairing: No Fairing radius (cm): 3 Nose Cone: Shape: conical Material: hollow plastic Propulsion: Water (liters): .4 Pressure (KPa): 350 Fin Design: Fin Height: 9 Fin Shape: trapezoidal Number of Fins: 3 Fin Dimensions: 9cm, 9cm Launch Stats: Max Altitude (m): 7 Max Velocity (m/s): 9 Launch Stats: Max Altitude (m): 0 Max Velocity (m/s): 1

Hang Time

For hang time, we want it to go high.  However, it needs to be stable which means it will probably be heavier.  It will be more stable if the center of mass is above the center of pressure.

Nose Cone

 Usually, the nose will be mostly conical (hence the name "nose cone") with an opening at the top where you can place your non-pointed object (ping pong balls, etc.). 

Center of Mass

http://tclauset.org/21_BtlRockets/BTL.html (third video)

We want the center off mass to be towards the top of the rocket so it flies straighter.  We can find where the center off mass is by balancing the rocket on an finger.  The center of mass can be moved upward by adding weight to the nose cone.  The rocket should weigh 200-240g.