MS 309 Manufacturing Processes I Project Presentation

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MS 309 Manufacturing Processes IProject
Presentation

• Marine Propellers
• Group 12
• Sabanci University
• 2007

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Istanbul Dockyard Command Headquarters

• Production for the navy on a project shop basis
• Fourth biggest dockyard in Europe
• Marine propeller production for navy

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Product Information

• Used in various ships, submarines
• Propellers are commonly used devices which
  transmits power by converting it into thrust for
  propulsion
• Momentum or acceleration of the water results in
  a force which we can call thrust.
• Propellers are both pushing and being pulled
  through the water

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Common Parts
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Design specifications

• Fatigue failure
• When the propeller is subjected to a
  cycling loading for a long time, a structural
  damage may occur on the surface of the material
  even if the stress value is much less than the
  ultimate tensile stress.
• Smooth surfaces are needed to prevent this
  phenomena and this problem is overcomed up to
  some level by grinding method that makes the
  propeller surface smoother.

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Design specifications

• Cavitation
• A thermodynamic process occuring in the
  inlet of the propeller due to the very high
  speeds gained by water molecules. The pressure
  decrease rapidly causing water molecules to
  vaporize and damage the blades.

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Design specifications
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Design specifications

• Static-Dynamic balancing
• Cavitation tests

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Common Parts

• Leading Edge Part of the bladewhich first cuts
  the water.
• Trailing Edge Part of the blade which water
  leaves through.
• Blade Root Part that blade and hub connects.
• Hub The metal surface that generally transmits
  the propeller thrust through the forward thrust
  hub.

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Raw Material

• Aliminium Basic standard material. Light weight
  and strength. Easy machining.
• Stainless Steel For high performance and
  strength. 24-10 SST Alloy.
• Bronze/Nibral Nibral means nickel and used for
  hardness. Commonly used for inboard props.

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Processes

• Modelling
• Casting CO2 sand casting, concrete sand casting,
  arda casting and the regular sand casting
• Finishing
• Grinding
• Static-Dynamic balancing
• Pitchometer tests
• Cavitation tests

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Casting

• Istanbul Dockyard Command Headquarters use 4
  types
• of casting techniques. We will focus on Arda
  Casting.
• Propellers shape is created by using mills.
• First, centers are determined.
• Then, the mill is located toward the center. One
  of the blades is completed by rotation technique.
  While doing this the reference is the center that
  was pre-determined.
• Repeating this process, other blades are formed
  continuously.
• After all the blades are completed, a good
  surface quality is maintained by further
  operations.

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Finished Product
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REFERENCES

• Pictures from
• sites.mercurymarine.com/portal/page?_pageid126,48
  572,126_49275_dadportal_schemaPORTAL
• http//xahlee.org/Whirlwheel_dir/boat/propeller3.j
  pg