Mini-SubmarineRandy DraegerGrant StocktonDavid Upp

Problem Statement As High School students, we have not fully investigated or applied the concepts and applications of electronics, fluid dynamics, energy systems, mechanical systems, calculus and physics in the construction and use of submersible technologies

Entirely math, physics, and engineering based Challenging to make all components work in unison Realistic goal, and submersibles have a place in the modern world

Group Development Randy – Leader due to personal

experiences and strong will for the completion of the project

Grant – Scribe due to neat hand writing and attention to detail

David – Time Keeper due to his past experiences with engineering and his ability to accurately a lot time for each task

Background First submarine made by Dutch. Used oars underwater for

propulsion First military submarine was produced by an American

Nicknamed Turtle Failed during trial run in the civil war Consequently submarine projects were abandoned until the 20th

century

Modified with internal combustion engines, newer ballast control systems, silent propulsion systems, a nuclear missiles

Customer Mr. Pritchard – ITC instructor and will serve as our

supervisor Ms. Brandner – AP Calculus BC instructor and will serve as

our mathematical and physics expert

Project Scope Research, design and build submersible Deliverables:

Submarine Final Report Final PowerPoint Presentation

Consult Experts: Teachers Hobby Experts Hardware Experts

Less than $400

Research• How does a submarine work?• What materials are submersibles made out of?• How do RC components work underwater?• Ballast Systems• Hull Design• Propulsion Systems

How does a submarine work?

How does a submarine work?

Archimedes’ Principle

Free Force Body Diagram The force of weight is combating the

force of buoyancy Recall as the volume of the object

decreases, so does the buoyant force This allows the force of weight to take a

more pronounced effect in bringing the submarine down underwater

When the volume increases, buoyancy becomes stronger, forcing the object towards the surface

How is neutral buoyancy obtained?

Ballast Systems Gas vs. Piston Lifespan of solutions Ease of installation and troubleshooting

Hull Design Wet vs. Dry Hull PVC is optimal because it

is a polymer / composite with a density near 1 and rather strong

Propulsion Propellers attached to waterproof

motor Ranking characteristics for power

Angular frequency Slant length Length of blade Number of blades

RC Components Water disrupts radio waves AM frequency will go down to 20 feet

good reception FM frequency stops at 5 feet RC frequencies stop around 4 feet

underwater Possibility of extending the receiver

wire to the surface in tether cord

Criteria Must function underwater Waterproof Electronic components are protected (safety) Movement with 3 degrees of Freedom Ballast System Maintain Neutral Buoyancy [still and motion] Diving range 5-10 ft. Video Feed (optional) Lighting (optional)

Constraints Limited weight due to

buoyancy Limited Budgets ($400) Materials must withstand

underwater pressure All materials must run off

the same power source with the voltage drop

Depth is limited to tether line

Explore Possibilities Submarine vs. ROV Wet vs. Dry Hull Piston vs. Gas Remote Control vs. Tether

Randy’s Design

David’s Design

Grant’s design

Select an approach

Criteria Design 1 (Randy) Design 2 (Grant) Design 3 (David)

3 degrees of freedom

4 3 4

Waterproof 3 5 3

Camera Feed 5 3 3

Functional (underwater)

1 1 1

Diving range below 4 ft.

1 1 1

Electronics protected

Y Y Y

 Total 14 13 12

Initial Design Saddle Ballast Tank Design

Wanted to keep ballast tanks away from the center hull to keep electronics dry

Middle tube is dry 2 outside tubes are the ballast

tanks Gas powered ballast

Solenoid Valves release air

Mathematical Based Design The ballast tanks must be large enough to

change the volume of water displaced to the point that the submarine will sink

Based on our list of materials, and Randy’s design, the mass is estimated to be around 36 pounds or 16.329 kilograms

The center hull must be four inches with an access port in the middle for electronics, and ballast must be adjusted accordingly

Mathematical Based Design 16.329 kilograms Assuming a 16.329 kilogram mass, the

volume must be around 16.329 liters to be neutrally buoyant (density = 1)

Volume of center hull 7.492 L Volume of access port .227 L Volume of motors .140 L Volume of solenoid boxes .442 L Total Volume without ballast tanks is 8.301 L

Mathematical Based Design Total Volume for neutral buoyancy must be 16.329 L Total Volume without ballast tanks is 8.301 L

Total Volume assuming 4” diameter ballast tanks is 23.285 L Total Volume assuming 6” diameter ballast tanks is 41.968 L Volume of air in both dust off containers is 8.000 L Percentage of ballast tank used assuming 4” ballast is

approximately 46% to sink = 8.091 L of air space Percentage of ballast tank used assuming 6” ballast is

approximately 94% = 1.638 L of air space

Mathematical Based Design Volume of air in both dust off containers is

8.000 L 4” Ballast has 8.091 L of air space 6” Ballast has 1.638 L of air space

Assuming that the ballast tanks may at one point become 100% full, the air in the dust off containers would not be enough to cause the 4” ballast submarine to surface, and it would forever be sunk

The six inch PVC could resurface if 100% full

Prototyping• Everything was cut first• Then all the pieces were assembled• Divide and Conquer• Took 1 ½ months for first prototype

Assembly

In the navy

Safety Glasses

Testing Round 1 – March 25, 2011

Specs TestPurpose

Verify that the submarine is within dimension constraints

Procedure Measure the length, width, and height

Expected Results Submarine fits within the required

2’x2’x3’ space

Actual Results Submarine fits within the required

2’x2’x3’ space PASS

0

10

20

30

40

Value (in)

Length Height

Dimension Axis

Dimension Test

Data

Constraint

Electrical Safety TestPurpose

Verify that no electrical current was leaking out into the water. Avoid electrical shock

Procedure Using a circuit tester, run one end to ground, and

test the surfaces of the submarine and tether Submerge submarine in water, and test water for a

current

Expected Results No electrical leak

Actual Results Electric wires were fully insulated. No electrical

current found PASS

Operational Ballast TestPurpose

Verify that the submarine can move up and down properly through ballast manipulation

Procedure Set Submarine in water, and connect wiring Open solenoid valves and allow sub to sink Record depth it sank to Resurface

Operational Ballast TestExpected Results

Sink to a depth of 5-10 feet Resurface

Actual Results Did not sink FAIL

Propelled Buoyancy TestPurpose

Ensure buoyancy system is operational during motion

Procedure Attain neutral buoyancy Move in obstacle (cage)

Expected results Pass with obstacle

Results Never Sunk

Stationary Neutral BuoyancyPurpose

Verify buoyancy while not moving

Procedure Attain neutral buoyancy Measure time at neutrally

buoyant

Expected results Prototype attains neutral

buoyancy

Results Never sunk

Three Degrees of FreedomPurpose

Verify the submarine moves along all three axis’ of motion

Procedure Submerge Attain neutral buoyancy Navigate through obstacle Perform 360 degree turn Come back through obstacle Surface

Three Degrees of FreedomExpected Results

Submerge Attain neutral buoyancy Navigate through obstacle Perform 360 degree turn Come back through obstacle Surface

Results Never sunk

Video FeedPurpose

Check webcam is providing input

Procedure Plug in webcam Use geometric shapes to verify input

Expected results Webcam provides input

Results Webcam passed the test, but later was damaged by a water

leak and no footage was recorded for any test

Waterproof Test Purpose

To test the central hull and ballast tanks for leaks. Avoid electrical damage

Procedure Hold submarine vertically Insert into water layer by layer, noting

where water leaked

Expected results No leaks

Results Leaks occurred around bolts and wires Silicone did not seal the submarine

Test photos

Test conclusions• Waterproofing• Buoyancy Issues• Further Refinements needed

Refining• Outer Body

• Fiber glass shell

• Waterproofing• Center of Buoyancy

• Added 3.4 pound Weight to Adjust center of mass over center of buoyancy

• Web Cam remained ruined• Tether Tension

• Top Cap Screw counter twist