HELYX-Marine is an extension module for HELYX developed by ENGYS in conjunction with Prof. Kevin Maki of the Department of Naval Architecture and Marine Engineering of the University of Michigan. The module incorporates a comprehensive set of CFD solvers and simulation tools to cover the main aspects of hydrodynamic analysis and design optimisation of naval and maritime applications.


Calm water Resistance

The specialised fast solver for calm water ship hull resistance calculations in HELYX-Marine features a unique method that combines a steady-state RANS viscous flow solution in the vicinity of the hull with a specialised boundary condition to model the free-surface elevation. This method is suitable for low Froude numbers and slender body hulls, for which it has has proven to deliver accurate results for both pressure and viscous hull resistance up to 100 times faster than the more traditional VOF multi-phase approach. The improved convergence speeds reported with this solver makes it ideal to perform automatic hull form optimisation using parametric surface morphing.


The following features are included as standard with the HELYX-Marine add-on module:

Fast steady-state resistance solver: for calm water ship hull resistance prediction with support for sinkage and trim calculations.
Transient 6DoF rigid-body motion solver: for seakeeping analysis, dynamic sinkage and trim and added resistance calculations.
MRF and body-force models: for simulating propeller effects in steady-state conditions.
Self-propulsion model: for simulating the propeller in transient motion using a fixed speed or variable speed via PID control system.
Regular and irregular waves models: for realistic seakeeping conditions.
Fully supported in HELYX-GUI: for simplified ease-of-use.

 

Seakeeping Analysis

HELYX-Marine features two transient mesh-motion solvers for different applications. The 5DoF solver is employed to mimic a towed ship at a constant speed in the model basin by enforcing the surge motion, whereas the 6DoF solver is employed to predict the motion of floating bodies on or near the air-water interface. The 5DoF method is particularly suitable for simulating seakeeping conditions with waves and propulsion, dynamic sinkage and trim and added resistance in waves. With the introduction of self-propulsion models and relative mesh motion in later version of HELYX, it will also become possible to use the 6DoF solver to introduce motion control and dynamic tracking to simulate manoeuvring characteristics.

 

Sea-keeping CFD analysis of the KCS Moeri hull form showing free-surface elevation.

 

References

Geremia P., Maki K. et.al. "Flow Resistance and Seakeeping Advanced Optimization of Ship Hulls Using HELYX-EcoMarine", OFW10 2015.

Geremia P., Maki K. et.al. "Hull Design Method Combining an Innovative Flow Solver Coupled with Efficient Multivariate Analysis and Optimization Strategies". COMPIT 2012.

 

Want to Buy?

The utilities and solvers in HELYX-Marine are released under the GNU General Public License for the benefit of the end-user. For further information about HELYX-Marine features, availability and prices, please contact us today or speak to one of our local sales representatives.