Part II: The Payload

The Comparative Analysis of Airflow Around a Rocket

PROJECT TEMPEST1

Part I: Vehicle

2Major Milestone ScheduleMarch 21Second test flight of full-scale vehicle

April 12Rocket ready for launchApril 16Rocket Fair/Hardware & Safety checkApril 19SLI Launch Day3First stage burn Stage separation.Booster coasts to its apogee and deploys main parachute.Booster lands safelySecond stage motor burnSustainer reaches apogee, deploys drogue parachuteSustainer descends under drogue parachute to 700ft Main parachute deploys, slowing rocket to safe landing speed of 15-20 fps. Sustainer lands safely.

Flight Sequence4Success CriteriaStable launch of the vehicle Target altitude of one mile reachedSmooth stage separation. Proper deployment of all parachutesSafe recovery of the booster and the sustainer

5Length 156.5Diameter6Liftoff weight37.4 lb.Motor K1275 Redline (54mm)CP118.8 (from nosetip)CG 101.8 (from nosetip)Static Margin 4.23 calibers

Entire Rocket6Length 94Diameter4Liftoff weight12.7 lb.Motor J380 Smokey Sam (54mm)CP83.8 (from nosetip)CG63.6 (from nosetip)Static Margin 5.04 calibers

Sustainer7

LetterPartLetterPartANoseconeHPayload BayBMain Parachute IPayload ElectronicsCSustainer E-BayJDrogue ParachuteDFins KMotor MountETransitionLMain ParachuteFBooster E-BayMPayload ElectronicsGFinsNMotor MountRocket Schematics8Fins: 1/32 G10 fiberglass + 1/8 balsa sandwichBody: fiberglass tubing, fiberglass couplersBulkheads: 1/2 plywood Motor Mount: 54mm phenolic tubing, 1/2 plywood centering rings Nosecone: commercially made plastic noseconeRail Buttons: large size nylon buttonsMotor Retention system: Aeropack screw-on motor retainerAnchors: 1/4 stainless steel U-BoltsEpoxy: West System with appropriate fillersConstruction Materials9Thrust Curve

10Acceleration Profile

11Velocity Profile

12Altitude Profile

13BoosterSustainerFlight Stability Static Margin4.23

5.04

Thrust to Weight Ratio

6.155.29Velocity at Launch Guide Departure: 54 mph(launch rail length 144)

Flight Safety Parameters14Wp - ejection charge weight in pounds. dP - ejection charge pressure, 15psiV - free volume in cubic inches. R - combustion gas constant, 22.16 ft- lbf/lbm R for FFFF black powder.T - combustion gas temperature, 3307 degrees R

Wp = dP * V / (R * T)Ejection Charge Calculations15Ejection charges have been verified using static testing.Calculated Ejection ChargesSectionEjection ChargeBooster2.15 g (of FFFF black powder)Sustainer (Drogue)2.0 gSustainer (Main)3.15 gStage Separation Charge1.0 g16ComponentWeightParachute DiameterDescent RateBooster(predicted)399 oz92 in.(main)17.6fpsSustainer (measured)211 oz24 in.(drogue)54.7 fpsSustainer(measured)211 oz60 in.(main)17.5 fpsParachutes17Tested Components

C1: Body (including construction techniques)C2: AltimeterC3: Data Acquisition System (custom computer board and sensors)C4: ParachutesC5: FinsC6: PayloadC7: Ejection chargesC8: Launch systemC9: Motor mountC10: BeaconsC11: Shock cords and anchorsC12: Rocket stabilityC13: Second stage separation and ignition electronics/chargesVerification Matrix18Verification TestsV1 Integrity Test: applying force to verify durability.V2 Parachute Drop Test: testing parachute functionality.V3 Tension Test: applying force to the parachute shock cords to test durabilityV4 Prototype Flight: testing the feasibility of the vehicle with a scale model.V5 Functionality Test: test of basic functionality of a device on the groundV6 Altimeter Ground Test: place the altimeter in a closed container and decrease air pressure to simulate altitude changes. Verify that both the apogee and preset altitude events fire. (Estes igniters or low resistance bulbs can be used for verification).V7 Electronic Deployment Test: test to determine if the electronics can ignite the deployment charges.V8 Ejection Test: test that the deployment charges have the right amount of force to cause parachute deployment and/or planned component separation.V9 Computer Simulation: use RockSim to predict the behavior of the launch vehicle.V10 Integration Test: ensure that the payload fits smoothly and snuggly into the vehicle, and is robust enough to withstand flight stresses.Verification Matrix19Verification MatrixV 1V 2 V 3V 4 V 5 V 6 V 7V 8 V 9V 10C 1C 2C 3C 4C 5C 6PPC 7C 8C 9C 10C 11C 12C1320Full Scale Vehicle Launch

21Liftoff Weight: 34 lbsMotor:BoosterK1100 TSustainerI599NLength: 157 inchesDiameter:6inStability Margin:Booster4.53Sustainer5.88Vehicle Parameters22Test dual deployment avionics Test full deployment schemeTest validity of simulation resultsTest rocket stabilityTest staging schemeFlight Objectives23Apogee: 2519 ftRockSim Prediction:2479 ftTime to apogee: 12 seconds Apogee events: drogueSustainer main parachute: 700 ft

Sustainer Flight Results24

Apogee EventsSustainer Main Parachute DeploymentSustainer True ApogeeSustainer Flight DataTemporary Altimeter #2Power FailureBoosterApogee25DescriptionInitial Pointtime, altitudeEnd Pointtime, altitudeDescent RateSustainer Descent with Drogue13.5s, 2466ft

54.5s, 700ft43.0 fps

Sustainer Descent with Main58.0s, 588 ft97.5s, 0ft14.9 fps

Booster Descent with Main (unopened)10.6, 845ft18.7, 0ft104 fps

Measured Decent Rates26

Recorded dataSimulation results(updated CD)Apogee = 2519ftApogee = 2479ftFlight Simulations vs. Data27Part II: The Payload28Experiment ConceptWe will use an array of pressure sensors to observe the airflow characteristics around several obstacles during a two stage flight.

After flight, we will test the rocket in a wind tunnel and compare the results.

29Experiment Concept

Artificial protrusions (obstacles) will be placed on the sustainer body to create disturbances in airflow.

AirflowPressure sensors will measure the local pressure before and after the protrusions30Payload Sequence

The sequence of our payload as it goes from flight to the final report. 31Payload ObjectivesDetermine the effect of obstacles on the surface of rocket on airflow around the rocket

Determine the accuracy of wind tunnel testing

32Payload Success CriteriaObstacles remain attached to the rocket during flight.

Sensors will successfully collect and store measureable data during flight.

Data collected is reliable and accurate.

33

The payload will measure the airflow around the rocket using an array of pressure sensors.The location of the pressure sensors are shown in red and obstacles are shown in blue.Data Acquisition34Sampling rate: 100 times per second

Sampling resolution:16 bits(2 LSB noise expected)

100kPa full scale range(15kPa ~ 115kPa)

Sampling locations: 12 on sustainer and 12 on booster

Data Acquisition35Data connections

Each data acquisition board (DAB) reads and stores data from 6 pressure sensors

Analog signals from the sensors are carried to the digitizer (ADC) using a shielded cable

All DABs in the same stage are activated by the same G-switch

shielded cableCommon G-switchsensorDataacquisition36Electronics

Data Acquisition Board: controls signal digitization, receives and storesdigitized data from pressure sensorsSensor Board: hosts a single pressure sensor and signal conditioning (noise suppression) circuitryElectrical schematics for DAB: shows the components and connections between themIntegration PlanFinParachuteData Processing and StorageMotorFin TabSensor package38SustainerDiagram of the sustainer showing the payload integration.DPSUnitTimerAltSensor packageParachute Compartment39BoosterDiagram of the Booster showing the payload integration.Fin TabFinMotorAltAltParachuteDPS&SParachute Compartment40VariablesIndependent VariablesType and location of obstacles.. LAir density outside of rocket..... DSpeed of air flow. SAir pressure PAcceleration profile.. X,Y,Z

Dependent VariablesPressure at each sensor... Yi41ControlsIdentical rocket in wind tunnel and actual flight

Identical obstacles on rocket in wind tunnel and actual flight

Similar wind speeds in wind tunnel and actual flight of first stage

Identical sensors and method of data storage

42CorrelationsPrimary correlations

Yx = f(L) (local pressure vs. location) Yx = f(S) (local pressure vs. airspeed) Data from wind tunnel test and actual flight will be compared

Further correlations from actual flightpressure vs. selected independent variables

43Test and MeasurementTestMeasurementPressurePressure will be collected at least 100 times per second by the sensor array44Verification MatrixComponents

Pressure SensorsBattery PackAltimeter3D AccelerometerObstaclesVerification Tests

Drop TestConnection and Basic Functionality TestPressure Sensor TestScale Model FlightDurability TestAcceleration TestBattery Capacity Test45Verification MatrixP=PLANNEDF=FINISHEDT E S T S1234567COMPONENTS

1FFP2FFF3FFFFF4FFFP5FFF46Relevance of Data, Accuracy and Error Analysis

Simulated pressure profile at 100mphPredicted pressure changes: -400Pa .. +300Pa

47Relevance of Data, Accuracy and Error Analysis

Simulated pressure profile at 250mphSimulated pressure profile at 250mphPredicted pressure changes: -2,000Pa .. +1,500Pa

48Relevance of Data, Accuracy and Error Analysis Resolution: true 14 bit(16 bit digitization with 2 LSB noise)14 bits = 16,384 signal levelsSensor range: 100,000Pa (15,000 115,000Pa)

100,000Pa / 16,384 levels = 6.10Pa / level

Expected pressure differences:

@ 100mph: -400Pa ~ +300Pa 114 levels @ 250mph: -2,000Pa ~ +1,500Pa 573 levels49Questions?