Electromagnetic Expulsion of a Cylindrical Body from an Outer Tube - - PowerPoint PPT Presentation
Team 2020 Electromagnetic Expulsion of a Cylindrical Body from an Outer Tube NAVAL UNDERSEA WARFARE CENTER Team ECE Members ME Members Abhishek Dutta, Advisor Jiong Tang, Advisor Alexander Podgorski Joshua Dupont Alexandra Paulakos
NAVAL UNDERSEA WARFARE CENTER
ECE Members Abhishek Dutta, Advisor Alexander Podgorski Alexandra Paulakos Joseph Slivinski ME Members Jiong Tang, Advisor Joshua Dupont Nickolai Serebriakov Patrick Haggarty NUWC Contacts Mike Sheahan, Technical & Integration Lead, Michael.E.Sheahan@Navy.mil James Leblanc, James.M.LeBlank@Navy.mil
▪ Main Goal: Expel a Cylindrical Body from a Tube into Water ▪ Main Principle: Induced Electromagnetic Force ▪ Basis: Take last year's proof-of-concept design & improve efficiency/performance ▪ Planned Improvements: more powerful multi-stage firing mechanism, high resolution data capture, & parametric simulation
▪ Metal pressure boundary must be used and isolate water tank from access
Figure 1: Initial Mechanical Layout
▪ Maximize utilization of space inside the metallic pressure boundary ▪ 2.25" payload within a 2.5" inner diameter tube ▪ Three stages of electromagnetic coils to overcome fluid resistance ▪ Control & data acquisition performed by a microcontroller ▪ Data acquisition on the individual capacitor voltages & coil currents to monitor and refine transients
▪ 3 capacitor banks
▪ Single 250V, 30mF capacitor
▪ MOSFET power module
▪ 250V operating conditions
▪ Rise/fall times depend on L & C ▪ ESR limits peak current
Figure 2: Approximated PFN Circuit Setup
State Microcontroller Capacitor Gate Circuit OFF OFF Discharge Disabled ON ON Discharge Disabled CHARGE ON Charge Disabled ARM ON Hold the charge Enabled
Table 1: Four States of Pulse Forming Network
Equation 1: Number of Turns Equation 2: ESR Resistance Equation 3: Coil Inductance
Figure 3: Coil Inductance & ESR @ 2" coil width
Figure 4: Coil Inductance & ESR @ 3" coil width
▪ Boost Converter ▪ UCC28056Power Factor Controller IC ▪ Converter charges in less than 60 seconds, controller keeps it at a steady voltage ▪ Prototype was built/tested with a DC power supply & worked as intended ▪ Was planning on testing with an AC power supply when returning from Spring Break
Figure 5: Charge Controller Circuit
▪ 115Vac input power will be through a standard NEMA 15-5 wall plug to a C14 AC power inlet module like the back of a PC power supply ▪ Power switch, cartridge fuse, & breaker included as safety isolations ▪ 130VA transformer used as a 1:1 current limiting isolation with additional fuses on output
▪ An 8-bit Arduino microcontroller would be used to manage control & logging ▪ Three GPIO outputs used for PFN trigger circuits ▪ One GPIO output to control the charge circuit isolation prior to launch ▪ Two GPIO inputs for user control ▪ Serial Communications port to read & record ADC values
▪ An 8 Channel, 24 bit, 256ksps Sigma Delta ADC monitors capacitor voltage & discharge current during launch events
▪ Each stage has a precision bidirectional current shunt in line with the coil to measure injected & flyback current
Figure 7: ME Rig Model Figure 6: ME Rig Constructed
watertight acrylic tank
both ends by manual watertight hatches
Stainless Steel pipe with 0.200" wall thickness
bottom for loading/launching
to fluid flow
Final Arrangement: One 3" wide coil, Two 2" wide coils
Plastic
together for printing ease
slipped over launch tube
paths
to maintain orientation during assembly & use Figure 9: Final Assembly Figure 8: Exploded & Transparent view of a single carrier
▪ Tube Materials Tested: (using a carbon steel slug)
▪ Aluminum ▪ 316 Stainless Steel ▪ Titanium
▪ Jump Test: V ertical Launch in Air ▪ V elocity Test: Horizontal Launch in Air ▪ Water Test: Horizontal Launch in Water ▪ Results:
▪ Stainless Steel was found to be the best material ▪ Launching in water reduced payload energy by 1/10th
Figure 10: Water Test Setup
▪
ANSYS allows linking of different simulation systems. ▪ ANSYS Maxwell 2D:
▪ Provides computationally simple itineration's on geometry. ▪ Data on cross sectional field strength, force, acceleration, & flux distribution. ▪ Provides physical simulation of flux linking between coils
▪ ANSYS Nexim:
▪ Provides SPICE analysis of components ▪ Integrates circuit design with magneto dynamic simulation of Maxwell
▪ Multiple simulation cases ran until useful magnetic performance determined ▪ Simulation can be validated & refined with test data
Figure 11: Final NEXIM model, 1st stage
Stage Turn Count Gauge 1st 300 16Ga 2nd 200 14Ga 3rd 200 14Ga
Table 2: Final Stage Configuration
▪ A convergence study was performed
determine efficient use of computational resources. ▪ Mesh size of 0.010" was determined to be required for repeatable results, with 0.100" used for rapid design itineration ▪ Time step of 0.1ms was chosen for final results, with 0.5ms used for bulk itineration
Figure 12: Time step and mesh size convergence comparisons
▪ 2D Transient resulted in a max payload velocity of 21 ft/s and a peak force of 270 ft-lbs ▪ The minimum target payload speed of 10 ft/s is easily achieved. ▪ The buildup of eddy currents in the stainless steel tube causes a slow field rise & a notable "suckback" effect as the coils stop adding energy to the system
Figure 13: Plot of resultant force, velocity, and position from simulation
▪ This simulation shows the field strength & slug position over an 80ms time frame ▪ The coils are the white boxes ▪ The launch payload is pushed out of the tube by the steel slug ▪ At 0ms the first coil is energized ▪ At 32ms the final coil is no longer being supplied additional energy, the fields collapse through the flyback diode ▪ The damping effect of the fluid motion as well as the magnetic suckback of the slug is clearly visible
Figure 14: Simulation Animation
▪ The 120Vac/250Vdc system are designed to be enclosed in a clear polycarbonate enclosure for safety ▪ Nylon bolts, nuts, hinges, & latches were procured for ease of maintenece while preventing inadvertent exposure to HV arcs ▪ Capacitors, Bus Bar, Current Shunts, MOSFET, & Diodes, as well as control circuitry all contained within. ▪ Two sets of relays disconnect the charge circuitry & discharge the capacitors when the system is off
▪ A control box providing low voltage control circuitry ▪ Four Position Key Switch -
▪ OFF: All power removed, capacitors paralleled with resistors ▪ ON: Power provided to microcontroller circuitry, capacitors discharge ▪ CHARGE: Power provided to charge circuit ▪ ARM: Launch button enabled
▪ Launch Switch
▪ Initiates microcontroller launch sequence if the key switch is in ARM position
Table 3: Expended Budget
Component QTY Item Cost Subtotal Capacitor 3 $101.79 $305.37 Switch 3 $36.33 $108.99 Current Shunt 3 $15.79 $47.37 FlybackDiode 3 $7.60 $22.80 Bus Bar 1 $16.74 $16.74 Breaker 1 $41.18 $41.18 Switched Power Module 1 $11.65 $11.65 Power Cord 1 $4.08 $4.08 Keylock Switch 1 $34.47 $34.47 Launch Switch 1 $8.25 $8.25 Component QTY Item Cost Subtotal BoltM5-12mm 1 box $6.27 $6.27 M5 Washer 1 box $4.62 $4.62 Copper Washers 1 Box $6.99 $6.99 Polycarbonate sheet 1 $75.43 $75.43 Polycarbonate angle 1 $11.69 $11.69 Nylon Bolts 1 box $9.05 $9.05 Nylon Nuts 1 box $7.95 $7.95 Enclosure Hinge 2 $4.88 $9.76 Enclosure Latch 2 $1.15 $2.30 14Ga enameled Wire 800 ft $115.26 $115.26 Component QTY Item Cost Subtotal Fuse Holder 4 $1.48 $5.92 Fuses 10 $0.19 $1.94 Transformer 1 $44.88 $44.88
Budget Expended: $902.96 / $1000 Budget Remaining: $97.04 / $1000
Component QTY Item Cost Subtotal Gate Trigger PCB 1 $10 $10 Power Supply PCB 1 $30 $30 Data Logging and Interface PCB 1 $20 $20 Data logging ADC 1 $35.01 $35.01
Table 4: Unprocured items
Note: PCB Cost includes manufacture & passive component cost
Total: $95.01
▪ Overview:
▪ Alex Podgorski: Simulation, Modeling, and Systems Integration ▪ Alex Paulakos: Pulse Forming Network and Coils ▪ Joseph Silvinski: Charge Controller and Data Logger
Table 5: Team RACI Chart