Magnetohydrodynamic Boat GROUP 6 Jeffrey Schaffer Alex Mavrommatis

Magnetohydrodynamic Boat GROUP 6: Jeffrey Schaffer Alex Mavrommatis David Hobbs Jared Kelley 1/16/2022 Group 6 Senior Design 2 Summer 2011 1

Motivation • To design a boat that can operate on the MHD technology • Take something that has only been realized in science fiction and make it a reality • Design a wireless system that can control the boat from a distance 1/16/2022 Group 6 Senior Design 2 Summer 2011 2

Overview of the Project 1/16/2022 Group 6 Senior Design 2 Summer 2011 3

Magnetohydrodynamic Jeffery Schaffer 1/16/2022 Group 6 Senior Design 2 Summer 2011 4

MHD Overview • Magnetohydrodynamics • Made popular by “The Hunt for Red October” • No moving parts. • Silent • Can be used as a generator or motor. • Can be scaled up using a superconducting magnet. 1/16/2022 Group 6 Senior Design 2 Summer 2011 5

MHD Objectives • The propulsion system must be able to withstand corrosion from the electrolysis generated from operation. • The metal contact must not interfere with the magnetic field lines so they must be made of a diamagnetic material. • The propulsion system must be insulated such that the losses are kept to a minimum. 1/16/2022 Group 6 Senior Design 2 Summer 2011 6

MHD Specifications • The MHD drive must provide 5 lbs of thrust. • The MHD drive must be lightweight in order to keep with the 10 lb boat requirement. • The MHD power supply must provide 24 V and capable of discharging 10 A for 15 minutes. • The MHD power supply must be under 8 lbs. • The MHD drive must provide enough thrust to achieve a 5 MPH top speed. 1/16/2022 Group 6 Senior Design 2 Summer 2011 7

MHD Magnets • Block magnets allowed for an isolated channel design. • 2 - 1. 32 Tesla neodymium rare earth magnets. • Total weight of 245. 8 grams. 1/16/2022 Group 6 Senior Design 2 Summer 2011 8

MHD Power Source 1/16/2022 Group 6 Senior Design 2 Summer 2011 9

Calculations 1/16/2022 Group 6 Senior Design 2 Summer 2011 10

MHD Prototyping Prototype 1. 0 (2/2011) • Isolated channel • Insulated • Aluminum contacts • 5. 5” x 1. 5” 1/16/2022 Group 6 Senior Design 2 Summer 2011 11

MHD Prototyping • • • Isolated channel Insulated Copper contacts 4” x 1. 5” Designed to allow for easy modification. 1/16/2022 Group 6 Senior Design 2 Summer 2011 12

Obstacles/Path Forward • • Optimization Mounting to boat hull. Operation under new batteries needs testing. Integration with current control hardware. 1/16/2022 Group 6 Senior Design 2 Summer 2011 13

Variable Current Source • Utilizes two LM 138 Precision Current Limiters. • Provides On-Chip thermal overload protection for the power transistor • Provides a constant regulated current output. 1/16/2022 Group 6 Senior Design 2 Summer 2011 14

Variable Current Source Design Stage 1: • The LM 138 develops a 1. 25 V reference voltage (Vref) between the Common and VREG pins of the device, we then use R 1 to set our maximum output current. • This completes the first stage of the current supply by providing a constant 5 Amp output to be used in the LOW, MED and HIGH speed settings. 1/16/2022 Group 6 Senior Design 2 Summer 2011 15

Stage 2: • We now want to drop a portion of Vref using a 10 m. A current sink, this gives us the ability to vary the output current. LOW SPEED (S 2 Closed): MEDIUM SPEED (S 2 and S 3 Closed): HIGH SPEED (S 4 Closed): 1/16/2022 Group 6 Senior Design 2 Summer 2011 16

1/16/2022 Group 6 Senior Design 2 Summer 2011 17

The Microcontroller Alex Mavrommatis 1/16/2022 Group 6 Senior Design 2 Summer 2011 18

MSP 430 • • Technical Support Price Versatility and Compatibility Easy to program 1/16/2022 Group 6 Senior Design 2 Summer 2011 19

MCU and Data Display 1/16/2022 Group 6 Senior Design 2 Summer 2011 20

MCU and Current Control • The Microcontroller will act as a switch for the current control system • There will be four different states that will represent different speeds • The MCU will be programmed using logic to output the different combinations and states for current control 1/16/2022 Group 6 Senior Design 2 Summer 2011 21

Current Control Logic • We need to represent four speeds, off, slow, medium, fast. • We can implement this with a 2: 4 decoder 1/16/2022 S 1 S 2 A B C 0 0 0 1 0 1 1 1 0 0 Group 6 Senior Design 2 Summer 2011 22

MCU and Servo Motor • The MSP 430 controls motor using Pulse Width Modulation • Pulse width minimum – turn left • Pulse width neutral – no change • Pulse width maximum – turn right 1/16/2022 Group 6 Senior Design 2 Summer 2011 23

The Wireless Design David Hobbs 1/16/2022 Group 6 Senior Design 2 Summer 2011 24

Requirements for the Wireless control • The range of the wireless must reach at least a minimum of 50 feet. • The user interface must display the current and voltage that remains onboard the Boat. • Must display the direction of the rudders onboard the boat. • Must be easy to learn and interface with. 1/16/2022 Group 6 Senior Design 2 Summer 2011 25

The Wireless options Type Frequency Range Cost TX Cost RX Controller Cost Chronos 433 -Mhz ~300 ft $50 $100 Included with TX Wi-Fi 2. 4 -Ghz 50 -100 ft i. Phone $55 $15 app Zigbee Sub 1 -Ghz 33 -246 ft ~$200 ~15 RC Car controller 27 -Mhz ~30 ft $5. 00 Included 1/16/2022 Group 6 Senior Design 2 Summer 2011 26

Receiver/ Transmitter • Transmitter is located in the watch • 433 Mhz Receiver 1/16/2022 Group 6 Senior Design 2 Summer 2011 27

Onboard power information • Current display • Voltage display • Estimated Time Remaining 1/16/2022 Group 6 Senior Design 2 Summer 2011 28

Directional control display • Enables the user to visually see the direction of the rudders • Left • Far left • Right • Far right • Center 1/16/2022 Group 6 Senior Design 2 Summer 2011 29

Current Control • Located on the “*“ button • High- 10 Amps • Medium- 7. 5 Amps • Low- 5 amps • Push button selection • High, Medium, Low • 1. . . 2…High 1/16/2022 Group 6 Senior Design 2 Summer 2011 30

Demo Mode • Located on the “#” button • Will step through low, medium, high current • Move the rudders • Step back down through current settings 1/16/2022 Group 6 Senior Design 2 Summer 2011 31

What’s left for the wireless? • Coding the watch to display the current and voltage • Coding the watch for the rudder direction display • Coding the watch’s demo mode • Coding the watch’s current control • Syncing the watch to the wireless receiver 1/16/2022 Group 6 Senior Design 2 Summer 2011 32

Budget Component Estimated Cost Actual Cost Magnets $100 $50 Boat Hull $60 TBD Wireless Receiver $50 Handheld RC $50 MCU $15 $4 Power Sources $40 TBD Propulsion Control $20 $50 Directional Control Motors $40 $0 PCB $75 TBD Misc. $50 TBD Total $500 TBD 1/16/2022 Group 6 Senior Design 2 Summer 2011 33

Completion Percentage Research Design Acquisition Prototyping Testing Total 0 1/16/2022 10 20 30 40 50 Group 6 Senior Design 2 Summer 2011 60 70 80 90 100 34