Randy Draeger Grant Stockton David Upp Mini-Submarine Randy Draeger Grant Stockton David 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 Waterproof 5 Camera Feed Functional (underwater) 1 Diving range below 4 ft. Electronics protected Y Total 14 13 12
Initial Design Saddle Ballast Tank Design Solenoid Valves release air 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
Safety Glasses In the navy
Testing Round 1 – March 25, 2011
Specs Test Purpose Procedure Expected Results Actual Results 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 PASS
Electrical Safety Test Purpose 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 Test Purpose 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 Test Expected Results Sink to a depth of 5-10 feet Resurface Actual Results Did not sink FAIL
Propelled Buoyancy Test Purpose 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 Buoyancy Purpose 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 Freedom Purpose 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 Freedom Expected Results Submerge Attain neutral buoyancy Navigate through obstacle Perform 360 degree turn Come back through obstacle Surface Results Never sunk
Video Feed Purpose Procedure Expected results Results 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 Procedure Expected results Results 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 Waterproofing Center of Buoyancy 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
Further Testing – April 10, 2011
Operational Ballast Trial Initial Conditions Met Video Feed Register Time To Sink (s) Depth (ft) Level Submarine Resurface Watertight Central Hull Pass/ Fail 1 Yes None 741 3 No Fail 2 747 740
Operational Ballast Volume Of Submarine: 41968.25056 mL Mass Of Submarine: 17874.77532 g Initial Density: 0.820 kg/L Initial Buoyancy: 411.286 N Density At Submersion: 1.000 kg/L Buoyancy At Submersion: 175.173 N Change In Volume Through Submersion: 24.093 L Change In Buoyancy Through Submersion: 236.113 Percent Of Ballast Tanks Filled With Water To Submerge: 88.23%
Propelled Neutral Buoyancy Dove underwater but did not attain neutral buoyancy Inclined dive due to center of mass alignment
Stationary Neutral Buoyancy Dove underwater but did not attain neutral buoyancy Inclined dive due to center of mass alignment
Three Degrees Of Freedom Dove underwater but did not attain neutral buoyancy Inclined dive due to center of mass alignment
Waterproof Test Purpose Procedure Expected results Results 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 One leak was found on the viewport
Test Conclusions Inclined dive cannot be righted Still not waterproof although significant improvement shown
Refining Epoxy over front porthole for sealing A 45 pound weight was added to the submarine Realigns center of mass with center of buoyancy Drastically alter initial density Requires less water in ballast system to submerge Less water weight in the ballast system will stop the system from performing a torque as easily Faster sink time
Final Testing – April 22, 2011
Operational Ballast Trial Initial Conditions Met Video Feed Register Time To Sink (s) Depth (ft) Level Submarine Resurface Watertight Central Hull Pass/ Fail 1 Yes None 293 8.0 No Part. Pass 2 295 3 290
Operational Ballast Volume Of Submarine: 44804.35156 mL Mass Of Submarine: 36740.98132 g Initial Density: 0.426 kg/L Initial Buoyancy: 439.083 N Density At Submersion: 1.000 kg/L Buoyancy At Submersion: 360.062 N Change In Volume Through Submersion: 8.063 L Change In Buoyancy Through Submersion: 202.97 Percent Of Ballast Tanks Filled With Water To Submerge: 29.53%
Operational Ballast
Operational Ballast
Operational Ballast
Operational Ballast
Propelled Neutral Buoyancy Dove underwater but did not attain neutral buoyancy Inclined dive due to center of mass alignment
Stationary Neutral Buoyancy Dove underwater but did not attain neutral buoyancy Inclined dive due to center of mass alignment
Three Degrees Of Freedom Dove underwater but did not attain neutral buoyancy Inclined dive due to center of mass alignment
Test Conclusions Adding the weight did not help keep the submarine from inclining Waterproofing was finally successful Voltage drop is too great for the receiver extension wire
Future refinements Trim tanks Some other form of ascension Propeller Placement
Lessons Learned (Randy) Unforeseen Problems Construction Physics Importance of calculations
Lessons Learned (Grant) Water can be hard to seal out Fiberglass is a mess Dust Off does not taste good Center of Mass means a lot Physics does exist Calculus has a practical application Remote control can be unpredictable Spare at least as much time in refinement as you do your original prototype Do it right the first time
Lessons Learned (David) Water is a challenge Importance of physics concepts Do not procrastinate Calculus has a purpose
Summary The submarine did not achieve all that it was set out to do, but gave it a good shot Physics and calculus are used before you design something It can be hard to make all systems run simultaneously Test for waterproofing by parts not the full submarine at once This was the most productive and eventful work team and project in the Academy due to our past experiences