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