1. Adam Hertzlin Dustin Bordonaro Jake Gray Santiago Murcia Yoem Clara P14651: Drop Tower for Microgravity Simulation

2. Project Summary Problem Goals Design & Build Drop Tower Vacuum Piping Structure Cost Effective Effective Cycle Time Aesthetically Pleasing Precision in Measurements Educational User Interface Access for Object Transfer Adaptability for Future Development Constraints Location and design approval from the dean(s) Material availability/size (ex. tube, pump) The device is aesthetically pleasing The tower 6” – 12” Diameter The device can be operated year round. The system is safe to operate. The project budget is $3,000. Team must justify the need for additional funds. The project must be completed in 2 semesters.

3. Project Deliverables Installed drop tower Detailed design drawings and assembly manual Bill of materials User’s Guide for operation Designed Lab Experiments Determine gravity in the vacuum within 1% error Compare drag at different pressures and drag vs. acceleration Additional vacuum related experiments Fun and Educational Experience for Middle School Students Technical Paper Poster

4. Agenda Customer Meeting Updates Customer Requirements Engineering Requirements Proposed Concept Design Isolation Valve Cost Analysis List of experiments Concept and Architecture Development System Block Sub-systems Summary Risk Assessment Test Plan Bill of Materials

5. Customer Meeting Notes Account for Pipe Fitting Leaks in calculations How does Ultimate Pressure change with Leak Rate? Limit design to one tower Simple Prototype Fit two objects in one tower Allow for lift mechanism Design Concepts to Future Tower Development Go with 6-8 in. Diameter, approx. 10-15 ft. Tall Tower Measure new location heights Dr. K Lab Talk with Mark Smith about using MSD space Does Ultimate Pressure Effect object drop times Feather vs. Ball Bearing Use only one laser when dropping items to measure gravity Keep the educational aspect in mind

6. Customer Requirements Customer Rqmt. # ImportanceDescription CR19 Appropriate Tower Height CR29 Allow for Adjustable Pressure CR39 Display Tower Pressure CR49 Drop 2 objects simultaneously CR59 Drop objects with no horizontal motion CR69 Demonstrate standard local gravity within 1% CR79 Display important outputs accurately CR89 Allow full drop visibility and limit distortion CR99 Demonstrate drag vs. pressure CR109 Allow objects to be changed out CR119 Safe/Intuitive operation CR129 Educational and Inspiring CR133 Display Tower Temperature CR143 Design considers noise and power requirements and limits CR153 Components are properly maintained and stored CR163 Aesthetically pleasing CR173 Generate object lift mechanism concepts for future MSD CR183 Allow for further static experiments

7. Engineering Requirements Rqmt. # I Engr. Requirement (metric) Unit of Measure Marginal ValueIdeal Value SR19 Measure Relative Object Positionft0-15>Tower Height SR29 Measure Relative Object Drop Timesec0-2 SR39 Measure Pressurepsi0-14.7 SR49 Cycle Run Timemin1-10 mins1 min SR59 Pressure Leak Rate Minimizedpsi / sec0-?0 SR69 Aesthetic Structure with SupportsYes / NoYes SR79 No Horizontal Motionin0 - ?0 SR89 Tube Collapse PressureFOS0-55 SR99 Timing difference of object releasemillisecond0 - ?0 SR103 Tower Heightft10-1515 SR113 Tower Cross - Section (Diameter)in6-88 SR123 Pump Flow Rateft 3 /min2-1010 SR133 Measure Temperature% Error0-10 SR143 Impact Energy Dissipation MethodJoule0-(m max v final 2 /2)(m max v final 2 /2) SR153 Air Intake - Tower Pressure Change Rateft 3 /min0 - ?? SR163 Minimal Error in Calculations% error0 - 1%0% SR173 Aesthetic Data DisplayYes / NoYes SR183 Platform for Stationary Experimentsin(0.50*ID)-(0.99*ID)(0.99*ID)

8. Tube Diameter Selection Weighted Pros and Cons of Tower Diameter % WeightCriteria6" Dia8" Dia10" Dia 20%Low Cost431 10%Object Size234 10%Lift Mechanism Implementation Ease234 15%Evacuation Time431 10%Component Design (Drop Mechanism)233 15%Component Availability321 10%Accessability to Objects234 5%FOS for Implosion443 5%Support Structure444 100%3.052.952.35 Current Selection: 6" Diameter Tube

9. List of Experiments Dropping two objects simultaneously Measure Gravity Measure Drag Balloon Expansion Marshmallow Expansion Sound Insulator Plastic Bottle Compression Note: The following slides will attempt to justify the required tower pressure and size to complete these experiments

10. CONCEPT & ARCHITECTURE DEVELOPMENT

11. Proposed Concept Designs

12. Proposed Base Structure

13. Selected Concept Designs (part 1)

14. Selected Concept Designs (part 2)

15. Continuous Lift Concept #1

16. Continuous Lift Concept #2 Use pressure to control the up and down movement of a piston. The piston would transport the objects back to the top of the tower post drop. Air Seal

17. Sub-Systems I.Release Mechanism I.Release system Calculations II.Error Propagation I.Ultimate Pressure II.Sensors III.Air Control I.Evacuation time II.Leak Rate Analysis IV.Catching Mechanism I.Energy dissipation Calculations V.Piping system I.Critical external Pressure VI.Structure I.Tower height calculations II.Support Buckling

18. Tower Height Distributio n

19. Critical heights Total height drop at Dr. Kandlikar: Height of lab= 11’ 7” = 139” With a ceiling clearing of 12” Drop height = 93.5” = 7.791 Ft Drop time= 0.696 Seconds With a ceiling clearing of 22” Drop Height = 83.5” = 0.657Ft Drop Time = 0.657 Seconds Total height required for a 10 Ft drop height: H=13.79 Ft Critical Length of pipe lengths L1 and L2 Assuming a clearing of 12” Assuming L1= 1 Ft L2= 7.692 Ft Assuming L1= 2 Ft L2= 6.693 Ft

20. Engineering Analysis  Release Mechanism

23. Base Specifications 1.5” 0.375” 4.0” 0.375” 6.0” Polycarbonate Diameter = 6.0 in Thickness = 0.375 in ρ = 1.22 g/cm3 (0.0441 lb/in3) Hatch Doors Length = 1.5 in Width =4.0 in Thickness = 0.375 in

24. Electromagnet Specifications Electrical Specifications 12 VDC Operating temperature of -40F to 140F Holding Force 4.5lbs Physical Specifications Weight – 0.06lbs Diameter – 0.75in Height – 0.62in Other Specifications Quick Release Mechanism

25. Hinges Specifications Physical Specifications Height – 3.5in Width – 1.5in Depth – 0.21in Radius – 5/16in (0.3125in) Pin Specifications Length – 3.5in Radius – 9/16in (0.5625in )

26. FBD

27. Important Result Maximum object weight before magnets will disengage prematurely 5.6 lbs Does not include Factor of Safety Weight of both object combined

28. Engineering Analysis – Structure  Tower Height

29. Free Fall – No Air Resistance (Vacuum Conditions)

30. Free Fall –Air Resistance (Atmospheric Conditions)

31. Free Fall – Vacuum vs. Atmospheric Conditions

32. Engineering Analysis - Air Control  Ultimate Pressure & Gravity Error Effect

33. Gravity Calculation with 1% Error

34. Free Body Diagram of Object

35. Drag Force (Air Resistance)

36. Objects to calculate gravity Not all objects may be suitable for gravity calculations Objects vary by their mass, projected area and drag coefficient Assumptions: Max Tube Height = 15 ft Ideal Gas Room Temperature Standard Gravity Error in Time vs. Chamber Pressure is as follows for each object: Pressure (Pa) 21050100500101325 1.625" Steel Ball 0.0000% 0.0001%0.0005%0.10% 1" Steel Ball 0.0000% 0.0001%0.0002%0.0008%0.16% Ping Pong Ball 0.0002%0.0010%0.0049%0.0099%0.0495%10.25% Feather 0.0023%0.0117%0.0585%0.1169%0.5855%106.83% Paper 0.0130%0.0650%0.3254%0.6514%3.2801%352.56%

37. % Error in Time vs. Chamber Pressure (Graphically)

38. Engineering Analysis – Laser Sensor  Sensor

39. Specs Micro-Epsilon ILR-1030 15m Range 4-20mA Output 10ms Response time Tolerance Error in position +/- 5 mm (0.0164 ft) Error in time none Laser Distance Sensor

40. % Error in Gravity Summary 2 Pa10 Pa50 Pa100 Pa500 Pa101325 Pa 8ft15ft8ft15ft8ft15ft8ft15ft8ft15ft8ft15ft 1.625" Steel Ball 0.205%0.109%0.205%0.109%0.205%0.109%0.205%0.110%0.206%0.110%0.404%0.309% 1" Steel Ball 0.205%0.109%0.205%0.109%0.205%0.109%0.205%0.110%0.207%0.111%0.529%0.433% Ping Pong Ball 0.205%0.110%0.207%0.111%0.215%0.119%0.225%0.129%0.304%0.208%20.704%20.609% Feather 0.210%0.114%0.228%0.133%0.322%0.226%0.439%0.343%1.376%1.280%213.863%213.767% Paper 0.231%0.135%0.335%0.239%0.856%0.760%1.508%1.412%6.765%6.669%705.326%705.230%

41. Engineering Analysis - Air Control  Evacuation Time

42. Conductance Viscous Molecular

43. Equivalent Pipe Length Pipe fittings can cause losses within a piping system These include: elbows, tees, couplings, valves, diameters changes, etc. Tabulated values for Le/D can be used to adjust L in the conductance equations D = Diameter of Pipe Le = Equivalent Length Total Length = L + Le 1 + Le 2 + Le 3 + ….

44. Effective Pump Speed

45. Evacuation Time VP6D CPS Vacuum Pump 2 Stage Rotary Pump 15 micron Ultimate Vacuum Pump Speed – 6.25 cfm Price: $268.92

46. Engineering Analysis - Air Control  Leak Rate

47. Chamber Leak Rate Throughput, Q Units: (Pressure * Volume) / Time Pump Throughput, QP Where: Seff = Effective Pump Speed P = Pressure Leak Throughput, QL Where: dP/dt = Differential Pressure V = Chamber Volume Constants: Chamber Volume Temperature Atmospheric Pressure Leak Area Time Variables: Mass Flow Rate Chamber Pressure Leak Pump

48. Flow Regime Change Note: Assumes linear relationship (mass flow rate constant)

49. Engineering Analysis - Catching Mechanism  Energy Dissipation

50. Critical Dimensions of Impact Absorption material

51. Assuming a Object 1 mass of 2 lb. Assuming a Coefficient of Restitution of 0.712 Assuming a Ball Radius of 2in. Mass= Volume x density Volume= Area x Height Area= Pi x Radius^2 Height of energy absorbing material = 4.19 in ̴ 5 in

52. Engineering Analysis – Piping System  Critical External Pressure

53. Pipe Critical Pressure Calculations Desired Factor of Safety = 3-4 Pipe Dimensions Courtesy of Engineeringtoolbox.com *Specifications for white PVC

54. Engineering Analysis – Structure  Support Buckling

55. Schematic Worst case scenario: – 15’ Long PVC Schedule 40 – 8” Diameter – 10’ long square A513 tube So 10’ of buckling length Assumptions: – Weight of vacuum tube is split evenly between four connection points Tube Frame Pipe Riser Clamp

56. Depiction of Reaction Forces on Tube 10ft W /4 W/2 Eccentric Distance

57. Methods using Matlab: >> Buckling_Bisection F (lbf) is: 1616 FOS is: 84 The percent error is: 0.038 Parameters: 10ft long steel tube 1-1/2” square 0.120” wall A513 steel >> Buckling_False_Position F (lbf) is: 1617 FOS is: 84 The percent error is: 0.006

58. Support Buckling Results We achieve a FOS well over what we would ever need for the selected support frame in buckling under worst case scenario Our frame can support the weight of the tube, and is feasible We can, if desired, reduce frame cross-section size and thickness if further analyses show large FOS as well

59. Engineering Analysis – Structure  Leg Center Deflection

60. Worst case scenario: 15’ Long PVC Schedule 40 8” Diameter 10’ long square A513 tube1-1/2” 0.120” wall A513 steel Assumptions: Weight of vacuum is halved between the two legs, as is the upper frame structure 1 foot long leg Schematic

61. Reactions and Deflection In the diagram below, dimension a is the distance to the front support block and b is to the center of the wheel axel. F includes half the weight of the tube and the upper support structure Result: ymax=-3.30E- 04 inches

62. Engineering Analysis Summary Proposed Requirement Metrics Tower height: up to 5 meters (~16ft) Tower size: 6” Diameter Number of Towers: 1 Pump Speed: 6.25 cfm Pump Type: 2 stage Rotary (mechanical roughing pump) Evacuation Time: 5.25 mins Ultimate Pressure: 15 microns (0.015Torr or 2Pa) Negative (Critical) Pressure – Factor of Safety: 3.94 No Isolation Valves Manual Object Lifting Electromagnetic Release Mechanism Mobile Support Structure

63. Test Plan #Test DescriptionComments/Status 1Drop TestTest Fall Time of Selected Objects is Atmosphere 2Energy Dissipation ControlDrop heaviest object 3Test Release MechanismDrop Object from any height 4Position sensor accuracy for objectsSensors can be mounted / tested without tube 5Ultimate pressureConsidering pump size / leaks/ chamber volume 6Pressure gage accuracyConnect vacuum to pressure gage only 7Temperature gage accuracyCalibrate Sensor 8DAQ device inputsPosition and time (from sensor(s)) 9Computer Software OutputsComputer outputs from on DAQ & human inputs 10Tower stabilitySimulate maximum applied forces 11Extra vacuum testsHow things react inside our vacuum

64. Drop Tower Piping Schematic

65. Bill of Materials: 6” Diameter by 10ft Tall

66. Bill of Materials Con’t: 6” Diameter by 10ft Tall Final Total: $2558.56

67. Drop Tower Price Comparison Using the 6in diameter by 15ft tall tower as a datum, the chart shown below was produced.

68. Questions?