Design and development of high speed craft includes general design, intact damage and hydrodynamic stability, performance prediction and simulation, hull development, structural design and analysis and seakeeping performance. 

Propulsion System Integration is to ensure that the installed system meets or exceeds the expectations of the builder and customer.  The system is run through a simulation to determine fuel economy, acceleration, dynamic stability, etc.

Product Develop can take many forms.  The projects to date have been primarily marine related.

Propeller Design includes a wide range of vessel types including high speed counter-rotating propellers, tandem propellers and custom propellers for large yachts and commercial vessels.

I can offer a full range of propeller designs from small counter-rotating propellers to propellers over three meters in diameter.  The propellers are custom manufactured in Japan by Nakashima.

Performance Simulation

Performance simulation includes the prediction of planning craft in calm seas over the full speed range of the application.  The simulation is capable of predicting the performance of the boat taking into account the engine and drive system including a standard inboard, pod drive, outboard, surface drive or waterjet from single to quad installations.  The program will pick a propeller for the application and estimate top speed, cruise speed and idle speed.  The waterjet simulation uses affinity rules for determining the thrust versus engine RPM.  The outboard simulation uses the Newton-Radar Series and the counter-rotating propellers for pod drives are modeled using an equivalent single propeller.  The fuel map is based on typical high speed engines adjusted for the fuel consumption at rated RPM.

The program can integrate tank test results into the program instead of the standard modified Savitsky's Long Form.  The program calculates appendage drag, whisker spray and windage  under separate routines.  The whisker spray resistance is neglected above 40 knots. 

The program provides the added resistance and response spectrum heave, pitch and acceleration for Sea States 1 through 4 in head seas. 

The following are some of the results of a wide range of analysis problems that have been completed over the last couple of years.  The problems include a high performance muffler which discharged underwater with a bypass leg above the waterline to the development of the water surface in a sea state 5.

Cotty Fay Marine Design is excited to announce the addition of Computational Fluid Dynamics (CFD) to our tool box.   We can offer very competitive pricing for external hydrodynamics including resistance estimates using multiphase dynamic mesh with RANS turbulence models.  The package is OpenFoam and templates have been developed to accelerate the modeling and development of the domain and boundary conditions.  The modeling for running resistance estimates can be developed and run very quickly.   The computer time is 24-36 hours per speed point depending on speed.  The hull model can include spray rails, tunnels and chine details which the designer may want to investigate.

The second level of complexity would be to add the appendages to determine their drag and wake.  An optimization could be run or a range of parametric designs.  The superstructure and pilothouse can be added to investigate flow and forces due to wind forces.  The appendages would be modeled on a full hull using an LTS solver (Local Time Stepping).

The following are the latest finite element analysis projects that have been completed.   The analysis includes the dynamic response of a planing hull at speeds up to 54 knots.  The next application is a modal analysis and alignment procedure for a 54m patrol boat and the last application is a pedestal crane foundation on a 31m Fireboat.

The following cradle has been developed to be modular to provide the shipyard with the most flexibility in transporting docked vessels from an 1800 ton floating drydock to a terminal area.  The cradles allow the weight of the vessel to be safely transferred from the drydock blocks to the dollies and rolled off the floating drydock to land where the cradles are landed on a series of transfer blocks where the dollies are removed to be available for the next docking.

Wing in Ground Effect Craft - WIG

       The craft is an aircraft - boat hybrid.  The propulsion system is a 160 BHP driving a sixty inch air propeller.   Take-off speed is 64 knots with a top speed of 96 knots.   The payload is 1000 lbs with a maximum flight weight of 2500 lbs.