Solid Rocket Experiment ARO 102L Introduction of Astronautics Try Lam [email protected]

Solid Rocket Experiment

ARO 102L

Introduction of Astronautics

Try Lam

[email protected]

Burn

Coast

Descent

Mission Profile

Solid-Fueled Rocket Performance Project Objective: This project is intended to provide a basic introduction to the mechanics of rocket flight theory and experimentation with solid-fuel model rocket.

Three Phases 1.Static ground test2.Assemble the rocket in class3.Flying and flight measurement

Groups: •You will split into groups of 5 to 6. Each group will analytically predict the time it takes for each of the group’s rockets (5 or 6 rockets) to ascent, deploy their parachutes, and return to the ground.

Equipment:•NANO or Nimbs model rocket kit•Estes A8-3 solid-propellant model rocket engine•Assembly tools•Measuring tools•Stopwatch•Launch pad

Solid-Fueled Rocket Performance Project Procedures

Solid-Fueled Rocket Performance Project

Rocket Assembly•Carefully read and follow the instructions in the rocket kit!

Procedures


Measurements•Measure the body tube diameter for drag estimation. •Record the nose code shape for CD value.•With the unburned rocket engine temporarily installed in your rocket, measure the

• Rocket mass• Center of gravity location (form nose tip)

•Calculate the parachute’s drag coefficient by dropping the rocket with the parachute open

• Find a two story building and drop your rocket off with the parachute deployed.

• Measure the height dropped and the time it takes to fall.• Measure the effective diameter of the parachute• Compute the CD_para (below)

Procedures

where


Pre-Flight Operational Checks•Make sure that the nose cone can easily slip out of the body tube•Make sure the parachute is not tangles up (might want to add some baby powder to the parachute to ensure it doesn't stick or tangle).

Team Assignments•Rocket launcher = the owner of the rocket

• Record the mass before and after launch• Place rocket on launch pad (note which channel it is on)• Go to the launch table• Arm the launch system• Loudly count down “3-2-1-fire”• Push the igniter button

•Timers (x2)• Stand at sides of the launch area• Start timing when they here “fire” command• Record the time at maximum altitude and time to ground

Procedures


Team Assignments (continues)•Inclinometer (x2)

• Practice this before actual flight• Stand 50 yards away form the launch stand• Point the inclinometer at the rocket on the stand and pull the trigger to unlock

the pendulum pointer.• Follow the rocket’s flight path pointing the inclinometer like a gun sight• When the rocket reaches maximum altitude, the trigger will be released,

locking the inclinometer pointer at max inclination angle.• Record the angle

Procedures

Solid-Fueled Rocket Performance Project Inclinometer & Altitude Calculation


Pre-Flight Operational Checks•Make sure that the nose cone can easily slip out of the body tube•Make sure the parachute is not tangles up (might want to add some baby powder to the parachute to ensure it doesn't stick or tangle).

Launch Operations•See “Team Assignments”•Record the time to max altitude •Record the total time (launch to ground)•Record data from the inclinometer (max inclination)

Procedures


Engineering Calculations•Calculate how high (in meters) the rocket is expected to fly based on your measured mass and the published or measured characteristics of the A8-3 engine being used, and how long it will take to get to the max altitude.•You will have to estimate the drag coefficient of your rocket. Use the experimental drag coefficient graph, consider your rocket’s shape, have the fins been streamlined, shape of the nose cone, launch lug drag, etc.•From the Estes A8-3 model rocket engine specs, the rocket has a burn time of tB = 0.73 sec, average T = 3.18 N, and a burnout mass of 10.2 g, total impulse = 2.5 Ns. Write down yours

Post Launch Calculations

Specs Reported Values Your Values Comments

Burn Time, tB 0.73 secs

Average Thrust, T 3.18 N

Burn out mass 10.2 g Engine only

Total Impulse, Itotal 2.5 Ns Itotal = Σ (T × Δt )

Graph from “Model Rocket Altitude Performance”, Centuri Engineering Technical Information Report TIR-100, 1968


Engineering Calculations•Compute the total altitude (see “Useful Equations” slide)•Compute the total descent time (see “Useful Equations” slide)•Compute the total flight time (see “Useful Equations” slide)•Compare calculated results to recorded results

Post Launch Calculations


General•Each is group is to turn in a TYPED report with everyone’s data

Cover Page•Include course name, section number, experiment name, quarter, date•Include group number and names of the group members

Summary Page•Include objective•Include key objective •Include a brief conclusion•Include something like the table below

Report

Member Name

Sanded Fin?

Predicted Time to Max Alt.

(s)

Measured Time to

Max. Alt. (s)

% Error for time to Max.

Alt.

Predicted Max. Alt.

(m)

Measured Max. Alt.

(m) [inclinomet

er)

% Error for

Max. Alt.

Predicted Total Flight

Time (s)

Measured Total Flight

Time (s)

% Error of Total Flight Time

Parachute Open?

Bob Yes 5 6 20% 50 55 … … … 5% No

Sue No 6 7 … … … … … … … Yes


Rocket Description Page(s)•Include description of rocket, manufacturers, model, and engine type•Include pictures, photos, diagrams, and describe the assembly process.

Launch System Description Page(s)•Include description of launch system, platform, guide rods, and launch equipment•Include pictures, photos, diagram•Include a description of the launch process

• Described the launch mission profile• Include details of what you recorded

Parachute Pre-Launch Test Description Page(s)•Include description of parachute pre-launch test and the purpose of this test•Include pictures, photos, or diagram of what you did•Include equations and results form all member’s rockets (their Cd_para value, etc.)

Report


Static Engine Ground Pre-Launch Test Description Page(s)•Include description of static engine ground test and the purpose of this test•Include pictures, photos, or diagram of what you did•Include equations and results form the ground test (e.g., the Isp values, thrust vs. time plots)

Maximum Altitude Measurement Page(s)•Include description of the inclinometer device and the measurement technique•Include table and equations describing the conversion form recorded angle to altitude•Include photos, diagram, or pictures if you want•Discuss if wind conditions affected your measurements

Other Measurement Page(s)•Include description and discussion of any other measurements (if any)

Report


Calculation Page(s)•Include equations, discussions, and results•Include table of measurements, calculations, and errors•Discuss anything that might be an error source or what might affect your results

Conclusion Page(s)•Summarize the experiment, what you can do better, lessons learned, etc.

References

Appendix•Any raw data, tables, notes, equations you want to include

Report

Useful EquationsGeneral Equations

Thrusting (Burnout) Equations

Useful Equations

Coasting Equations

Coast + Thrust Altitude Equation

Descent Equations

Table of ResultsItem Symbol Values Units

Center of Gravity Location Xcg

Empty Mass of Rocket mrocket

Liftoff Mass of Rocket m

Pre-launch Motor Mass mmotor

Gravity g

Liftoff Weight W

Drag Coefficient CD

Diameter of Rocket d

Cross Section Area A

Field Elevation h

Air Density (at elevation) ρ

Engine Type Estes A8-3

Average Thrust T

Burn Time tb

Propellant Mass mprop

Specific Impulse Isp


Thrusting and Coasting Calculations

Burnout Velocity VB

Burnout Altitude hB

Coast Altitude hC

Coast Time tC

Total Altitude htotal

Parachute Descent Calculations

Parachute Diameter dpara

Parachute Area Apara

Drop Time (pre-flight) tdrop

Drop Distance(pre-flight) hdrop

Parachute Descent Velocity Vpara

Parachute Drag Coefficient CD_para

Descent Time tdescent

Total Flight Time ttotal


Performance Calculations

Exhaust Gas Velocity Ve

ΔV = Ve ln(minitial/mfinal) ΔV

Item Symbol Values Units

Compare Calculation to Test Data

Total Altitude (calculated) htotal_calc

Total Altitude (recorded) htotal_data

% difference (error) Erroralt

Total Flight Time (calc.) ttotal_calc

Total Flight Time (record.) ttotal_data

% difference (error) Errortime

AppendixModel Rocket Assembly Instructions

Model Rocket Engine

Model Rocket

Model Rocket

Model Rocket

Model Rocket

Documents

Solid Rocket Experiment ARO 102L Introduction of Astronautics Try Lam [email protected]