MAE 1202: AEROSPACE PRACTICUM Project Overview March 24 and 25, 2011 Mechanical and Aerospace Engineering Department Florida Institute of Technology D.

MAE 1202: AEROSPACE PRACTICUM

Project Overview

March 24 and 25, 2011

Mechanical and Aerospace Engineering Department

Florida Institute of Technology

D. R. Kirk

PROJECT OVERVIEW• Course project counts for ~ 35% of final grade

• Keep same teams as in laboratory

– 10 teams, 6-8 members each

– Try to work together as a team as best possible

– Largely responsible for grading your own team members

• Each team should select a team leader (organizer)

• Keep track of attendance in your teams if you like

• Make use of materials learned in MAE 1202

– Analytical tools (estimate drag, thrust, altitude, etc.)

• Using Word, Excel or MATLAB

– Pro|Engineer to do detailed design of model and technical drawings

– Make use of machine shop to fabricate components

• Preparation for Senior Design – some ideas, but on a much grander scale

BACKGROUND: SOUNDING ROCKETS• Sounding rockets are sub-orbital rockets that carry payload above Earth

– Do not place payload into orbit

– Often used for climatology, astronomy, micro-gravity experiments, etc.

Example of a Sounding Rocket For Investigation of the Ionosphere

FIT JAMSTAR Sounding Rocket,Senior Design Project (2003)

PROJECT DESCRIPTION• Launch and recover a rocket designed to fly to either 500 ft. or 1,000 ft.

– Hit either altitude as accurately as possible– See article ‘Team America: Rocketry Challenge 2004’ located in website

• Target altitude was 1,250 ft and winning team came within 5 ft• MAE 1202, 2006: Target altitude was 1,000 ft, winning team 998 ft!

• Wide open design space– Use your creativity and ingenuity to design any type of rocket you like– Make the rocket out of any materials you like (pursuant to a few rules)

• You will be provided with:– Some raw materials– Motor (your team’s choice)– All launch equipment– Altimeter used to measure maximum (apogee) altitude– $20 per team in additional funding– WRASP software

PROPULSION OPTIONS• 3 propulsion choices will be provided

• At least 3 rocket motors will be supplied to you

– At least 2 motors for testing

– At least 1 motor for launch contest

• Motor used will be AeroTech Rocketry E20-4, E20-7 or E30-7

– Motor mounting tube will be provided

E20 E30

Diameter (mm) 24 24

Length (cm) 6.5 7

Propellant Weight (g) 16 19

Total Weight (g) 49 43.4

Total Impulse (N s) 35 39.5

Delay Time Options 4 or 7 7

AEROTECH MOTOR THRUST CURVES

Time, s

Thr

ust

Motor ‘burns’ for ~ 1.2 seconds

THRUST CURVES

PROPULSION OPTIONS• E20 Motor will burn for about 1.6 seconds (E30 burns for about 1.2 s)

– Rocket is provided with thrust for about 1.6 seconds

• After burn out time, motor is no longer providing thrust

– Rocket has lots of kinetic energy and is coasting at high speed

– Rocket continues to gain altitude as kinetic energy is converted to potential energy

• After some prescribed time called the ‘delay time’, motor fires an ejection charge, which deploys parachute

– Can think of this as ‘coast time’ after powered flight but before ejection of parachute

• The choice that your team must make is: 4 or 7 second delay time

ALTITUDE MEASUREMENT• Each team will be supplied with a barometric altimeter to determine maximum

altitude achieved by the rocket

– Altimeter must be safely contained within payload bay of the rocket

– Must be recovered in working order

• Only a limited number of altimeters

– Continuously available for examination and test-fitting within rocket

Basic Layout of “AltimeterOne” Electronic AltimeterREF: http://www.apogeerockets.com/

Baseline Data for “AltimeterOne” Electronic AltimeterDimensions 1.93” L x 0.47”W x 0.64”T

Weight 6.7 grams (0.24 ounces)

Sampling Data Rate > 20 bps

Maximum Altitude 29,500 feet Above Sea Level

Resolution 0.82 feet at 25o C

Launch Detect 50 feet ASL

Operating Temperature -25o C to 49o C

ALTITUDE MEASUREMENT

• More information altimeter can be found at: http://www.apogeerockets.com/

MODEL ROCKET CONSTRUCTION• Your rocket must have the following:

– Motor (propulsion) system

– Payload housing to hold altimeter

– Parachute for safe recovery (or other recovery system)

• See safety rules located on page 6 of project document

• Your rocket must comply with all rules and regulations or rocket will not be permitted to fly regardless of how complete your calculations and rocket design are

WHERE DOES ENGINEERING COME IN?• Either delay time (4 or 7 seconds) for an E20 or E30 motor is capable of reaching

500 or 1,000 ft

– Actually both can go quite a bit higher

• Detailed analytical prediction for altitude is important part of grade

– How do you know that your rocket will be stable?

• Location of Center of Pressure (xcp) RELATIVE to Center of Gravity (xcg)

– Why (and how many) fins on rocket?

– How high will your rocket go with and without drag?

• How will your rocket be impacted by aerodynamic forces (drag)

• What is the CD of your rocket?

WHERE DOES ENGINEERING COME IN?• How do you control altitude?

– Make rocket suitable weight?

– Larger drag, cross-sectional area?

– Smooth surface, rough surface?

– Use your test flights to fine-tune design

• Altitude trade-off:

– Select 500 ft, and there is less distance to travel

– Select 1,000 ft, and you can ‘miss’ by larger amount

• Example, lets say:

– Team going to 500 ft gets an altitude of 550 ft ( = 50 ft, within 10%)

– Team going to 1,000 ft gets an altitude of 920 ft ( = 80 ft, within 8%)

PRELIMINARY PROJECT SCHEDULE

• Written Documents:

– Literature review and motor selection report: April 1 by 5 pm

– Final report: April 29 by 5pm

• Oral Presentations:

– Oral Presentations: April 21 or April 22 (lab)

• Launch Contest:

– April 23 (Saturday in Palm Bay)

LITERATURE REVIEW AND MOTOR SELECTIONDUE: April 1st

• Each team must submit document that summarizes progress on project

1. Literature review of how rocket performance predictions are made for small model rockets

• Demonstrate understanding of terminology

• Understand motor performance (thrust curve)

• How thrust, impulse and delay time impact your design

• Impact of weight on drag on design

2. Statement of target altitude team is trying to achieve

• Either 500 or 1,000 ft

3. Motor and delay time selected

• Either 4 or 7 seconds

• Comments on choices

• Brief summary of how you are working together as a team

• Approximately 5 doubled spaced typed pages

FINAL REPORT: DUE APRIL 29TH 1. Title page

2. Table of contents

3. Introduction

4. Team formation and division of work

5. Design alternatives

– Description of preliminary ideas with pros and cons of each

6. Analyses

– Summary of all calculations performed, equations used, sources

– Where are your calculations strong, where are calculations weak

7. Final design

– Description of final design, complete with Pro|Engineer drawings

8. Test flights and competition results

9. Summary and conclusions

10. References

11. Figures

PRACTICE AND LAUNCH CONTEST• Launch Contest

– DATE: April 23, 2011

– TIME: 9 am to 2 pm

– PLACE: Palm Bay, directions on next slide

• Not all team members have to be present at practice or contest

• Link Building Workshop Option

– Have team leader coordinate with Mr. Greg Peebles: [email protected], X7715

– Must have two team members in workshop at all times

• Pick up materials (1 motor, igniter, motor mount tubing, launch lugs, exact dimensions on altimeter case) in a few weeks

DIRECTIONS TO PALM BAY FIELD• Directions

1. Palm Bay road West past I-95 to Minton Road.

2. Take Minton south until it dead ends into Jupiter.

3. Turn right (west) on Jupiter

4. Make 2nd left onto Degroodt

5. Travel south on Degroodt until you reach Bombardier

6. (On southeast corner is Bayside High School)

7. Turn Right onto Bombardier (West)

8. Stay on Bombardier until it ends & you will see us

HELPFUL TIPS• Separate your payload bay (altimeter housing) from your ejection charge by an airtight

bulkhead. – The altimeter reads data from a sensitive diaphragm. If an ejection charge goes off (high pressure, hot gases,

and explosion) it could damage the altimeter

– Failure to do so may prevent your rocket from being able to launch

• Holes will need to be created on the body tube of your rocket so the altimeter can take ambient pressure readings.

• Car sponge will be provided to contain the altimeter inside your payload bay. Allow the car sponge to be wider than the body tube to reduce slippage and shaking.

• Remember to place a motor block at the end of your motor mount tube, this prevents the motor from shooting through the rocket. This will also require also require the ejection charge to move freely past the motor block. The placement needs to allow the motor to stick outside of the motor mount tube, which will allow easy insertion, and removal.

– If your motor slides inside the motor mount, masking tape will be provided at launch

• Remember to place one of your launch lugs near the liftoff center of gravity location.

• Do not concern yourself with recovery wadding, it will be provided at launch.

• Try to avoid a complex design, the simplest designs are least likely to fail.

• Remember to bring spare parts, super glue, etc. incase your rocket gets damaged.