http coueus comsistemadeobtenciondeimagenesmediantegloboestratosferico Acoustic Temperature Measurement of Lift

http: //coueus. com/sistema-de-obtencion-de-imagenes-mediante-globo-estratosferico/ Acoustic Temperature Measurement of Lift Gas in High-Altitude Balloons Preliminary Design Review 1

Our Student Team South Dakota School of Mines and Technology Jon Carnell Senior Mechanical Engineer Josh Fogel Junior Mechanical Engineer Jessica Teeslink Co-Team Lead Senior Electrical Engineer Matt Jones Junior Mechanical Engineer Aaron Vogel Junior Mechanical Engineer Nick Martinez Senior Electrical Engineer Dakotah Simpson Senior Electrical Engineer Nathan Williams Co-Team Lead Senior Mechanical Engineer 2

Our Faculty Team South Dakota School of Mines and Technology Mr. Lowell Kolb Dr. Jason Ash Dr. Charles Tolle SDSM&T EE Department Project PI SDSM&T ME Department Project Co-PI SDSM&T EE Department 3

Our Sponsors and Partners 4

Mission Overview -------------- • • • Mission Objective Theory and Concepts Expected Results Concept of Operation Success Criteria 5

Mission Overview: Objectives • The goal of this project is to measure the temperature and composition of the lift gas in high altitude balloons. This will give knowledge about the health of the balloon. • Temperature cannot be accurately measured right now because typical methods rely on convection • Objectives: • Gather meaningful, accurate, scientific data on the health of the balloon • Determine the temperature and mixture of the gas in the balloon 6

Mission Overview: Theory and Concepts 7

Mission Overview: Theory and Concepts cont. 8

Mission Overview: Theory and Concepts cont. 9

Mission Overview: Theory and Concepts cont. ● The frequency changes with gas composition nonlinearly ● The gas composition will need to be known to accurately calculate temperature 10

Mission Overview: Expected Results ● In air, the approximate slope is 4. 2 Hz/C ● In pure helium, the approximate slope is 12. 3 Hz/C ● Trend is not linear, but is a square root 11

Mission Overview: Expected Results cont. • Expect to measure temperatures down to -86°C • Expect to correlate balloon health to the temperature of the gas • Expect to determine the ratio of helium to air in the balloon 12

Mission Overview: Concept of Operation • The sensor may be placed in the apex, in the middle, or near the base of the balloon • The sensor will be able to make measurements at any altitude • The sensor data will be saved analyzed after the flight 13

Mission Overview: Minimum Success Criteria • Able to measure a difference in frequency due to a difference in temperature in very low pressures • Able to calculate the temperature of lift gas 14

Mission Overview: Comprehensive Success Criteria • Ability to determine the gas constant accurately • Ability to explore the trends between altitude, balloon health, and the temperature of the lift gas 15

System Overview -------------- • • Functional Block Diagram Critical Requirements 16

System Overview Functional Block Diagram 17

System Overview Critical Requirements Requirement Verification Method Description Acoustically measure the temperature of lift gas for high-altitude balloons Test Perform ground tests to compare Grubby Cell measurements with conventional thermal sensors Acoustically determine the gas composition of lift gas for high-altitude balloons Test Known gas compositions will be measured and compared 18

Subsyste m Overview -------------- • • Grubby Cell Gas Analyzer Chamber Radiation Shield Microprocessor/Storage 19

Subsystem Overview: Subsystem Overview • Acoustic Resonance Chamber (AKA: Grubby Cell) • Gas Analyzer Chamber • Solar Radiation Shield • Data Storage/Microcontroller 20

Subsystem Overview: Acoustic Resonance Chamber: Grubby Cell • The Grubby Cell will consist of a piezo speaker and two piezo microphones • The two microphones will be exactly the same for symmetry • The conducted path signal is subtracted from the air path signal to compensate for the tube resonating • The speaker will be powered by an amplifier 21

Subsystem Overview: Grubby Cell cont. 22

Subsystem Overview: Grubby Cell Geometry 23

Subsystem Overview: Grubby Cell Material Selection • Concerns • Thermal expansion of the material results in a change in wavelength • Friction fitted joints may loosen or tighten as temperature changes • Repeatability of geometry and physical properties • Machinability / consistent fabrication • Cost • Weight 24

Subsystem Overview: Grubby Cell Material Selection 25

Subsystem Overview: Concern: Thermal Contraction 26

Subsystem Overview: Gas Analyzer Chamber • Will utilize a Grubby Cell and a thermocouple to determine the composition of the lift gas (ratio of helium to air) • Pump will pressurize the chamber, so convection will occur at a reasonable rate (see next slide) • The thermocouple will measure the temperature of the air in the chamber • The Grubby Cell will measure the frequency resulting in knowing the speed of sound • The ratio of the adiabatic constant to the molecular weight can be calculated 27

Subsystem Overview: Gas Analyzer Chamber Cont. Proceedings of the World Congress on Engineering 2010 Vol II WCE 2010, June 30 - July 2, 2010, London, U. K. 28

Subsystem Overview: Gas Analyzer Chamber 29

Subsystem Overview: Gas Analyzer Chamber 30

Subsystem Overview: Gas Analyzer Chamber 31

Subsystem Overview: Gas Analyzer Chamber Pump Diaphragm Pump (Piston) ▪ Creates large vibrations ▪ Must heat diaphragm and reed valves ▪ Needs regulation reciprocation results in pressure waves ▪ Minimal design work needed ▪ Likely higher pressures Centrifugal Fan Minimal vibrations No need for heating No need for gas regulation Needs to be designed from scratch ▪ Likely lower pressures ▪ ▪ 32

Subsystem Overview: Preliminary Testing of Pressurized Grubby Cell 33

Subsystem Overview: Radiation Shield • Requirements • Must provide adequate shielding from both the sun and earth • Must provide structure for pump to be fixed • Minimize radiation between Grubby Cell and shield itself • Provide new air to be measured by Grubby Cell • Must suspend grubby cell in a way that vibrations/movement does not affect measurements 34

Subsystem Overview: Radiation Shield 35

Subsystem Overview: Radiation Shield 36

Subsystem Overview: Data Storage/Microcontroller 37

Subsystem Overview: Data Storage/Microcontroller • The microcontroller will be responsible for reading frequencies, performing calculations, and writing data to the memory • The data storage will be responsible for holding the data that is collected from the sensor • Data can include temperature measurements and gas mixtures • The data needs to be readable from the data storage to analyze it 38

Subsystem Overview: Data Storage/Microcontroller • The counter will be implemented using a Schmitt Trigger: • It converts the sine wave to a square wave • The output will be fed into a separate microcontroller • A timer will be used to find the frequency Source: ocw. mit. edu 39

Subsystem Overview: Data Storage/Microcontroller 40

Subsystem Overview: Data Storage/Microcontroller 41

Risk Matrices -------------- • • Overall Project Risk Subsystem Risk 42

Risk Matrices: Overall 5 Probability Severity 5 - Frequent 5 - Catastrophic 4 - Problem 4 - Significant 3 - Occasional 3 - Moderate 2 - Probable 2 - Light 1 - Improbable 1 - Negligible Probability 4 3 A F 2 D 1 CB 1 2 3 Severity 4 5 Item Mitigation Value A- Overweight Watch 6 B- Over power budget Watch 5 C- Breaks during landing Research 5 D- Unable to retrieve data Insulate 10 F- Inaccurate measurement Watch 9 43

Risk Matrices: Grubby Cell 5 Probability 4 C 3 A 2 1 BD 1 2 3 Severity 4 5 Probability Severity 5 - Frequent 5 - Catastrophic 4 - Problem 4 - Significant 3 - Occasional 3 - Moderate 2 - Probable 2 - Light 1 - Improbable 1 - Negligible Item Mitigation Value A- Movement causes inaccurate measurements Mitigate 15 B-Not enough gas to make sound Research 5 C-Too much radiated heat Shield 8 D-Brakes in low temp Research 5 44

Risk Matrices: Circuitry 5 Probability 4 3 2 D A 1 Probability Severity 5 - Frequent 5 - Catastrophic 4 - Problem 4 - Significant 3 - Occasional 3 - Moderate 2 - Probable 2 - Light 1 - Improbable 1 - Negligible BC 1 2 3 Severity 4 5 Item Mitigation Value A- Failure to save data Research 10 B- Too cold to function Insulate 5 C- Movements cause disconnects Mitigate 5 D- Fail to block spurs Research 6 45

Risk Matrices: Gas Analyzer 5 Probability 4 C B 3 2 D 1 Probability Severity 5 - Frequent 5 - Catastrophic 4 - Problem 4 - Significant 3 - Occasional 3 - Moderate 2 - Probable 2 - Light 1 - Improbable 1 - Negligible A 1 2 3 Severity 4 5 Item Mitigation Value A- Failure to reach necessary pressure Research 4 B- Vibrations cause inaccurate measurements Research 20 C- Radiation causes inaccurate measurements Shield 8 D- Pump fails to work in cold Insulate 10 46

Risk Matrices: Initial Testing 5 Probability 4 3 C 2 A 1 1 2 D B 3 4 Severity 5 Probability Severity 5 - Frequent 5 - Catastrophic 4 - Problem 4 - Significant 3 - Occasional 3 - Moderate 2 - Probable 2 - Light 1 - Improbable 1 - Negligible Item Mitigation Value A- Fail to reach and hold critical testing pressure (1 k. Pa) Watch 8 B- Fail to reach and hold critical testing Temperature (-80 C) Watch 4 C- Imprecise control of Helium/Air composition Research 9 D- Significant moisture accumulation within chamber Mitigate 3 47

Testing Plan -------------- • • Vacuum Chamber Cold Chamber 48

Initial Testing Plan: Vacuum Chamber • Built in house • Requirements • Gas intake/outlet port for air and helium exchange • Connecting port has butterfly valve for flow control • Single stage pressure regulator to control the amount of each gas piped into chamber • Hermetic connector for Grubby Cell, pressure sensor, and thermocouple/thermistor connection 49

Initial Testing Plan: Testing Regime • Air • Pull a vacuum to the lowest pressure we can get • Use pressure regulator to pipe in known quantity of air at room temperature • Test Grubby Cell and record pressures and frequencies • Repeat under high low temperature conditions of 20°C to -86°C • Helium • Repeat same procedure for helium gas 50

Initial Testing Plan: General Layout of Test Chamber 51

Initial Testing Plan: Chamber with Machined Flange Units in inches 52

Initial Testing Plan: Machined Cap 53

Initial Testing Plan: Detailed View of Assembly 54

Initial Testing Plan: Cold Chamber Design • Requirements • Two insulated chambers interconnected • One holding dry ice expelling cold air into cooler holding test chamber • Steady flow of cold air for chamber to reach equilibrium slowly 55

Project Management -------------- • • • Schedule (Gantt Chart) Contact Matrix Availability Matrix Budget Conclusions 56

Project Management Plan: Gantt Chart 57

Project Management Plan: Contact Matrix Name Position Email Phone Student Team Members Jessica Teeslink Team Co-Lead Jessica. Teeslink@mines. sdsmt. edu Electrical Engineering (605) 484 -5768 Nathan Williams Team Co-Lead Nathan. Williams@mines. sdsmt. edu Mechanical Engineering (605) 321 -5141 Dakotah Simpson Senior Electrical Dakotah. Simpson@mines. sdsmt. edu (605) 920 -0531 Jon Carnell Senior Mechanical Jon. Carnell@mines. sdsmt. edu (206) 818 -2260 Nicholas Martinez Senior Electrical Nicholas. Martinez@mines. sdsmt. edu (817) 271 -0095 Aaron Vogel Junior Mechanical Aaron. Vogel@mines. sdsmt. edu (402) 806 -7544 Josh Fogel Junior Mechanical Josh. Fogel@mines. sdsmt. edu (970) 405 -0954 Matthew Jones Junior Mechanical Matthew. Jones@mines. sdsmt. edu (720) 499 -7006 Advisers Mr. Lowell Kolb SDSM&T Faculty Adviser lowell. kolb@sdsmt. edu (605) 394 -1221 Dr. Jason Ash PI jason. ash@sdsmt. edu (605) 355 -3736 Dr. Charles Tolle Co-I charles. tolle@sdsmt. edu (605) 394 -6133 Tom Durkin SD Space Grant Adviser Thomas. durkin@sdsmt. edu Mark Ketcham Raven Aerostar Technical Adviser mark. ketcham@ravenind. com Mike Smith Raven Aerostar Technical Adviser mike. smith@ravenind. com NASA Contact Janet Letchworth POC / Mission Manager janet. letchworth@nasa. gov 58

Project Management Plan: Availability Matrix 59

Project Management Plan: Budget Considerations • Budget monitored by student Treasurer • All purchases are approved by PI, Student Team Co-Leads and Treasurer • Current Balance: approximately $130, 000 funds 60

Project Management Plan: NASA Proposed Budget 61

Project Management Plan: Conclusions • Worries: • Device will not work at low temperatures • Unable to precisely measure gas compositions • Failure to block majority of radiation • Action Items: • Earned value analysis • Testing chamber • Prototype circuit board • Final design 62

Partners and Sponsors: Acknowledgements Thank You 63