Naval Undersea Warfare Center [NUWC] ECE Team: Christian Corwel, - - PowerPoint PPT Presentation

ECE Team: Christian Corwel, George Zoghbi, Stevan Webb ME Team: Menna Elfouly, Austin Gallimore, & Liam Perkins Mentors: Dr. James LeBlanc, Mike Sheahan Faculty Advisor: Dr. Abhishek Dutta Naval Undersea Warfare Center [NUWC]

Presentation Outline

• 1. Overview and Requirements
• 2. Considered Design Concepts
• 3. Design Choice and Reasoning
• 4. Design Modeling and Simulation
• 5. Schedule and Budget

Project Overview

Electromagnetic Launchers are the Future

❖ More efficient than traditional launchers ❖ Require less space on vessel ❖ Capable of producing high exit velocities ❖ Higher Reliability Unmanned Underwater Vehicles are traditionally launched by pumping water behind a payload and using that force to expel the object from a tube

https://en.wikipedia.org/wiki/Torpedo_tube

System Requirements

Goal

To design and build an electromagnetic launch system that can expel a payload underwater from within a tube

Deliverables

❖ Fully functional underwater prototype ❖ Calculations of magnetic force on payload ❖ Simulations of circuit behavior and magnetic field

https://www.militaryaerospace.com/articles/2018/08/torpe do-guidance-sonar.html

Design Concept 1: MHD Pump

Pros

• Will launch any sized

payload

• Uses seawater to force

payload out of tube

• Highly reliable pump

used to launch

Cons

• Requires complicated

control circuit

• Low exit velocity
• Only functional in

seawater

• Difficult to scale for a

model

1) https://www.brighthubengineering.com/naval-architecture/60576-how-can-a-ship-be-moved-by-magneto-hydrodynamic-propulsion/ 2) https://www.intellectualventures.com

Design Concept 2: Railgun

Pros

• High exit velocity
• Simple circuit design
• Can launch in any

environment

• Using an armature

means different sized payloads can be launched

Cons

• Arcing can damage

rails

• Requires high

current/voltage

• Lower reliability

https://science.howstuffworks.com/rail-gun1.htm

Design Concept 3: Coilgun

Pros

• High launch size object

flexibility

• Simple circuit design
• Low build cost
• No mechanical

parts-high reliability

Cons

• Requires high current
• Generally lower exit

velocities

• Coils can increase

launcher weight

1) https://electronics.stackexchange.com/questions/8745/how-does-a-coilgun-work 2) http://hackedgadgets.com/wp-content/_coil_gun__2.jpg

Design Concept 4: EM Aircraft Launcher (EMALS)

Pros

• Carriage can ferry

payload at high velocities

• No mechanical contact

with the guiding rail

• Applicable to many

different systems

Cons

• Requires rail system

and carriage

• Must detach payload

from carriage

• Requires a large

amount of space

1) https://en.wikipedia.org/wiki/File:EMALS.JPG 2) https://www.geek.com/wp-content/uploads/2015/03/emals1-625x350.jpg

Design Assessment

Railgun Coilgun EMAL MHD Requirements Score (1-5) Score (1-5) Score (1-5) Score (1-5) Simplicity of Design 4 5 2 1 Simplicity of Circuit 4 5 3 1 Size/Weight Constraints 3 4 3 3 Power Required 3 3 2 2 Launch size flexibility 4 4 3 5 Reliability 3 5 3 4 Exit Velocity 5 4 4 2 Cost Effective 4 5 2 4 Total 30 35 22 22

Coilgun Electromagnetic Principles

Magnetic Field Induced by Current on a Straight Wire Magnetic Field Induced in a Solenoid Faraday’s Law of Induction

N = Number of Coil Turns dΦ/dt = Change in magnetic flux over the change of time B = Magnetic Field μo = Magnetic Permeability in Vacuum l = Length of the Coil I = Current (Amps)

https://physics.stackexchange.com

Coilgun Specifications

Number

• f Turns

Radius (inches) Length (inches) Inductance (mH) 200 2.5 5 5.01

N = Number of Turns A = Area of Solenoid μo = Magnetic Permeability l = Length of Solenoid L = Inductance of Solenoid

Calculation of Magnetic Field and Force

Current (Amps) Armature Radius (inch) Magnetic Field (B) Force (N) 60 1 ~0.1T ~7.97

B = Magnetic Field A = Area of the Armature μo = Magnetic Permeability in Vacuum F = Force on Object within Coil

Preliminary Test

Basic Prototype

Why is a Pulse of Current Needed?

https://www.youtube.com/watch?v=PMU9TQUDhow

1. Force pulls payload towards the center of the coil 2. Constant current will not launch the payload 3. A high current pulse will launch the payload

Preliminary Circuit Design

Rectified Circuit Response

ID = Diode Current Is = Saturation Current VD = Voltage Across the Diode n = Ideality Factor VT = Thermal Voltage

Circuit Components

❖ ❖ ❖ ❖ ❖ ❖ ❖

Launch Projections

• Payload to be neutrally buoyant with mass of

720g

• Dotted line represents time when payload

exits launch tube

• 2.05 m/s exit velocity

V = Velocity p = Density of Water Cd = Drag coefficient Af = Area of Front of UUV As = Area of Side of UUV

Launch Projections

%% Calculate Velocity tt = 1; % Total time for study (seconds) N = tt/.0001; % number of grid points for time V_instant = F/m; % Instantaneous velocity (m/s) dt = tt/N; % Time btwn grid points (seconds) V = V_instant*ones(1,N+1); % Velocity Vector (m/s) Dist = zeros(1,N+1); % Distance Vector (m) for i = 1:N dl = V(i)*dt; % Change in position for this grid point f_drag = (V(i)).^2 * Drag_Coeff; % Drag force (N) a = - f_drag./m; % Acceleration due to drag (m/s^2) dV = a*2*dl; % Change in velocity squared in this grid (m^2/s^2) V(i+1) = sqrt(V(i).^2+dV); % Velocity for next grid point (m/s) Dist(i+1) = Dist(i)+dl; % Distance traveled so far (m) if Dist(i) - .3 <.01 %This is when it leaves the cylinder exit_i = i; end

end

time = linspace(0,tt,N+1); % Time vector to match grid points above (s) exit_time = time(exit_i); % Time when the object leaves the tube (s) exit_velocity = V(exit_i); % Velocity of the exiting object (m/s) total_distance = Dist(end); % Total distance traveled at end of time points (m)

Project Budget

Part # Part Vendor Quantity Price

B00EFD0O4K TEMCo 18 AWG Copper Magnet Wire - 1 lb 199 ft 200°C Magnetic Coil Winding Amazon 1 $17.45 B074KJCQX2 1/4" Diameter, 304 Stainless Steel Round Rod, 12" Length, Extruded, 0.25 inch Dia Amazon 1 $7.79 B01HUA66PA 1/4" Diameter, 6061 Aluminum Round Rod, 4" Length, T6511, Extruded, 0.25 inch Dia Amazon 1 $6.31 B06XCPBCZD Solid Bare Copper Round Wire 5 Oz Spool Dead Soft 12 To 30 Ga (16 Ga/43 Ft) Amazon 1 $9.75 B000OM9J2O Polycarbonate Tubing, 3/4" ID x 1" OD x 1/8" Wall, Clear Color 24" L Amazon 1 $10.24 B008O9YIV6 MG Chemicals Silicone Modified Conformal Coating, 55 ml Bottle with Brush Cap Amazon 1 $12.95 B072C8G3XJ Sumnacon Dual Ended Crocodile Alligator Clips Amazon 1 $9.99 B01N8P5Q50 uxcell 5 Pcs JD1912 12V 100A 4 Pin SPDT Power Electromagnetic Relay w LED Light Amazon 1 $12.29 SLPX682M050C7P3 Cornell Dubilier - CDE SLPX682M050C7P3 Capacitor Mouser 10 $26.00 14822 Soft Iron Rod Xump 1 $12.29 360-3289-ND NKK Switches M2011SS1W01/UC Digikey 5 $16.85 B01BDB7MAK Remington Industries 16SNS Magnet Wire, Enameled Copper Wire, 16 AWG, 5.0 lb, 631' Length, 0.0520" Diameter, Red Amazon 1 $61.04 75C8905 VS-100BGQ100 - Schottky Rectifier, 100 V, 100 A, Single, PowerTab, 3 Pins, 1.01 V Digikey 2 $9.50 B07K78MPNT Magid Glove & Safety M-0-11-Y-10 Magid Class 0 Electrical Gloves, Capacity, Volume, Rubber, 10, Yellow Amazon 1 $55.00 B0014ZXTPS 3M 91264-80025 Chemical Splash/Impact Goggle, 1-Pack Amazon 2 $15.98 Total Price $283.43

Project Schedule

Thank You Any Questions?