we have most of the information readily available in the simulator posted.

- expected height 41.5 meters
- expected acceleration/g 75.5 m/s
- cost from the “cost function” spreadsheet 67
- drag coefficient: 0.3 cross-sectional area .9

Rye Kennedy Engr 101, Fall 2013

Archive for the 'Rocket Expected Performance' Category

Team # Task 3 – Expected Performance

December 6th, 2013

we have most of the information readily available in the simulator posted.

- expected height 41.5 meters
- expected acceleration/g 75.5 m/s
- cost from the “cost function” spreadsheet 67
- drag coefficient: 0.3 cross-sectional area .9

Task 3 Group 6 Team WitWiki

December 4th, 2013

Our team expected our rocket to go about 12 meters high at the optimization that we set it to. We thought that the rocket’s weight wouldn’t be too much and that our water would be just enough to get it off the ground and into the air.

This is our cost function for how we optimized our rocket.

Our expected score was 66 given that everything goes well and we get to the maximum height.

Team 4 Expected Performance (Kevin, Dylan, Jacob) Sprite Zero

November 30th, 2013

Running the tests was kind of complicated at first, since there are so many variables that can be altered. I think what we have should do pretty good, but keeping in mind the theoretical will always be higher than what it will launch. I saw that the drag had little effect on the height so I think going with the 2L was a good idea. I had also looked into fins, and found out that rectangle or parallelograms are the best shape and that we should use 3. We didn’t really know where to put the weight, but thinking about an arrow we put the weight on top. I enjoy the project so far, and I hope everything goes ok for lift-off!

-Jacob Simon

One of the things I am most worried about is the weight, because I distributed on the top so it would make a more solid “cutting” front like an arrow. The payload is not completely solid, so shifting has a huge effect on the trajectory. Because they are balls that are constantly shifting, it will distribute some of the energy horizontally, but that is not the goal. Because the construction of the rocket is a bit shoddy, the ideal and the realistic goals will have some disparity, but I see no reason that it would not take off. Next time, I would have liked to make the compartment more solid and squish the shots in closer so they would not move as much. Furthermore I would also have made it more efficient because the compartment has a ton of glue and tape, adding weight. Furthermore, when we placed the fins the fins were not measured, so they may be a bit off. Finally, I would’ve tried to bypass the tornado tube and just make the exhaust 1 cm from the get-go. I don’t think we will win because of our construction, but our optimization is impressive and our design just “feels” right. Construction has always been a really difficult weakness for me, but I’ve always really liked the directions I take (not because it’s my direction C: )

-Kevin Wong

Unfortunately we did not get a proper post-test evaluation because the launcher failed to give us a single launch.

In preparation for final launch day we will perform the following changes.

- We noticed many rockets coming apart and we all agreed that we would not mind greater mass for stronger durability. We are adding more glue to the rocket-nose to ensure it does not come apart midflight or after the second launch.
- The nozzle was too long to fit onto the launcher properly. We will cut down the nozzle to better fit the launcher.
- The protractor will have an angle mechanism on it (it broke off before the launches).
- The fill ratio will be increased slightly to about .35 or .36. We did not realize that water will be lost by placing it on the launcher and some in the air-pump. This will give us sufficient time to fully compress the bottle’s air and release it when we believe its about .33 fill ratio. Hopefully the launcher will be just fine by the final launch date.

PREDICTIONS

We believe that our rocket will reach about 25-30m. The optimization gives us 32.2m, but we did not consider the exact air drag. Furthermore while our mass was lower than expected, the launcher and wind gives us a lot of uncertainty. Furthermore we simply did not get to test launch so we cannot be sure exactly what is going to happen.

Team Kyle Steven Nick

November 25th, 2013

Performance

- expected height-according to the excel spreadsheet our expected height was 17.2 meters. When we launched our rocket the actual height was about 43 meters.
- expected acceleration/g-our expected acc/g was 64.6
- cost from the “cost function” spreadsheet- our total cost for this rocket was 212 and with the added height the final cost function is 255.
- drag coefficient and cross-sectional area- the drag coeff for our 2 liter bottle was .5 and the cross-sectional area was .076m^2

Description

Our design was a 2 liter bottle with a parabola shape at the top and very small bent fins at the bottom. The parabolic cone and fins were also made out of a 2 liter bottle. The 250g payload of bb’s was placed and centered in the parabola inside a bad and taped. Hot glue and packaging tape were used to hold the rocket together.

Specs

- 311.5 Grams total weight
- 80 psi
- 630 ml of water = filling ratio of .3
- Exhaust diameter of 2.1

Ryan Nick and Godliesen Task 3 – Expected Performance

November 24th, 2013

From the data we entered into the excel spreadsheets, we determined the following maximum values from our rocket design:

Max height: 40 M

Expected Acceleration: around 3 m/s

Cost: 78

These calculations are assuming that we can get the maximum pressure of 80 psi, and a good launch.

Team #3 – Expected Performance

November 24th, 2013

I am stuck on two designs for my bottle rocket. So I will just post about both and on the day of the launch i will decide.

Bottle Rocket Design #1:

Height: 27.74m

Acceleration: 3.6 m/s/s

Cost Function + Measured Height: 103

Bottle Rocket Design #2:

Height: 34.05m

Acceleration: 2.8m/s/s

Cost Function + Measured Heights: 102

Not much difference between the bottles, just slight modifications/changes but they both have the same overall designs and constraints. Not sure how I am going to choose between the two designs but we will see. And the performances all lie on the launcher and if it can give off the 80psi to the bottle. I am also adding strange design modifications to my rockets, it could either completely help the launch or destroy it.

Group 2: Corey, Mike, Tate, J.D

November 24th, 2013

Our original rocket had the measurements of

Mass: 361 g

Total volume: 1250 mL

Exhaust diameter: 2 cm

Pressure: Max

On test day our rocket reached a height of 26 feet

We found a smaller exhaust would yield a better cost function out put

New exhaust diameter: .5cm

We expect our rocket to travel about 15m high with a cost function value of 30