News

Opening Date Announced for Queensferry Crossing Bridge

August, 2017 (Scotland --)  The Queensferry Crossing Bridge, spanning the Firth of Forth in... READ MORE

News

Portland Tidal Power Firm Awarded Federal Grants

August, 2016 (Portland --) Maine Marine Composites will assist Ocean Renewable Power Company (ORPC)... READ MORE

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Maine Company Announced as Finalist for Wave Energy Prize

August, 2016 (Portland --) Maine Marine Composites (MMC) has completed an extensive analysis... READ MORE

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Maine Marine Composites Completes Research Study on Offshore Wind Turbines

September, 2015 (Portland --) Maine Marine Composites has completed a government funded study of... READ MORE

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MMC gives webinar on issues with mooring systems

Richard Akers, CTO of Maine Marine Composites, gave a webinar... READ MORE

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Maine Marine Composites Wins Federal Grant to Study Ocean Turbine Stress Limits

Jan 14, 2014 ( Portland-- )  Maine Marine Composites has been awarded... READ MORE

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MMC Completes Analyses for Waller Marine, Inc.

October 9, 2012 (Portland --) Maine Marine Composites, LLC (MMC) announced successful... READ MORE

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Maine Marine Composites Presents at IBEX 2012

Richard Akers, CTO of Maine Marine Composites, gave a presentation on "Advanced Analysis for... READ MORE

News

Maine Marine Composites Completes Hydrodynamics Analysis for Ocean Renewable Power Company

(Portland --) Maine Marine Composites, LLC (MMC) announced successful completion of a hydrodynamics... READ MORE

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Maine Marine Composites Receives Grant, Subcontract to Extend Analysis Capacity of Software

(Portland --) Maine Marine Composites, LLC has been awarded both a defense subcontract and... READ MORE

Why test?

  • Speed vs. power vs. boat loading
  • Maneuverability
  • Response to waves (seakeeping)
  • Possibilities of wave slamming
  • ...or do you need to model test as a sales tool to sell your design?

Model Construction

MMC personnel can assist you in constructing accurate models for tank testing or free-running experiments.

  • Convert your paper or CAD-based design to a model design using state-of-the-art hull design software
  • Recommend a model construction technique (built-up wood, FRP, foam, etc.) for your project
  • Build or manage the construction of your model

Lexan Model Lexan model of deep-Vee offshore fishing boat mounted on dynamometer at Webb Institute.

 

Tank Testing

Maine Marine Composites has established relationships with most of the hydrodynamics testing facilities (towing tanks) in North America, and can manage your entire testing program

  • Create a test matrix appropriate for your budget and design needs
  • Recommend the best test facility for your project, taking into account both your budget and your engineering requirements
  • Consult during the test program, or manage the entire program
  • Analyze the test data and create the final report, including recommendations for design changes if necessary

We will work with you to determine the model loading conditions, operating speeds and wave conditions. Tank testing can be expensive, and proper planning is required.

Typical Procedure:

  • Develop a test plan (address issues listed above)
  • Select a test facility based on ability to perform your desired tests, geographic proximity, professional reputation, and cost
  • Construct an exact scale model of your design including appendages, thrust objects, and anything else that will be wet during the test. We can help you with modeling issues ("Tankery") such as scaling issues and modeling techniques, and we can arrange for the construction of models from wood, plastic, or syntactic foam.
  • Consult with the tank staff to select one of the common wave models. You may want to use a simple ideal model such as Pierson-Moskowitz, or you may want to test against an actual spectrum obtained from an NDBC buoy located near your expected operating area.
  • Travel to the tank and set up your model. Preparation time for a typical set of tests can extend to a number of days, depending on how complicated your test procedure is.
  • Tank personnel will run the tests and collect the data. You should observe this process and participate if you can so that you understand exactly how the tests were performed.
  • The tank personnel will post process the data and issue a report. Neglect this step at your peril -- do you really know exactly how they ran the tests and how to scale the results?
  • Repack the model and ship it home (or ship it to your client to be placed in a glass showcase).

We can help you with any or all of this -- we've done it many times and we've collected a lot of tankery tricks over the years.



Carriage 5 at NSWC-CD

Testing personal watercraft (PWC) on high-speed carriage at  NSWC Carderock Division.




PWC On Carriage 5

Personal Watercraft mounted for high-speed run at NSWC Carderock.

Free-Running (Radio Controlled) Tests

Some tests have to be run in large basins or even lakes. It is difficult to perform maneuvering tests in a long, slender tank so engineers create radio controlled models and test them in sheltered lakes or basins.

MMC can design and construct radio-controlled models, including everything from the hull-form to the data telemetry system.

Virtual Tank Testing

Tank and model testing can be expensive. An alternative to tank testing is to simulate your design with a computer model, to perform virtual tank testing. Maine Marine Composites has a number of computer analysis tools that can meet some of your analysis needs at a fraction of the cost of a full-blown model testing program.

Results from radio-controlled MV Hugh Sharp model replicated using ANSYS-AQWA

 

The POWERSEA program

Developed by MMC staff, the POWERSEA program predicts the motion of a planing boat in calm water, regular or irregular seas. We specify the forward velocity or thrust and the shape of the waves or wave spectrum, and POWERSEA calculates the hull’s motion including surge, heave and pitch displacements, velocities and accelerations.

POWERSEA is used to predict time dependent effects such as porpoising, deck wetting and boat accelerations:

  • Speed/Power analyses of high-speed planing craft in calm water or waves.
  • Predicting heave, surge and pitch amplitude, velocity and acceleration at any point on the design.
  • Investigating porpoising (vertical oscillations) behavior.
  • Estimating dynamic natural frequencies of hull with respect to incident waves.
  • Investigating time dependent effects such as porpoising, deck wetting and boat accelerations.
Contact MMC for more information about the POWERSEA program.