HAMS

An open-source computer program for the analysis of wave diffraction and radiation of three-dimensional floating or submerged structures.

HAMS (Hydrodynamic Analysis of Marine Structures) is a free open-source software to analyse wave-structure interactions in the frequency domain. It is based on the boundary integral equation method within the framework of the potential flow theory. The code is currently written in FORTRAN 90. It has been developed by the author Yingyi Liu for nearly a decade.

HAMS is released in the hope that it will contribute to eliminating the inequality (for those who are not able to afford to purchase a costly commercial BEM software) in the continuous research developments related to offshore engineering and ocean renewable energies.

HAMS is freely distributed under the Apache License, Version 2.0, http://www.apache.org/licenses/LICENSE-2.0, and may be modified and extended by researchers who intend to enhance its capabilities and port the code to other platforms.

The success of HAMS should to a large extent be attributed to Prof. Bin Teng (Dalian University of Technology), who has tutored me the theory of potential flow in marine hydrodynamics and the programming skills using the Boundary Element Method. The code structure and the coding style of HAMS are exactly two of the examples that I have learned and inherited from Prof. Bin Teng.

Theoretical Basis

- Please refer to the following papers for the theory:

The theory of panel method that has been used by HAMS is written in detail in the following two papers:

• Yingyi Liu (2021). Introduction of the Open-Source Boundary Element Method Solver HAMS to the Ocean Renewable Energy Community. In: Proc. of the 14th European Wave and Tidal Energy Conference, Plymouth, UK, Sep. 5–9, 2021.

• Yingyi Liu (2019). "HAMS: A Frequency-Domain Preprocessor for Wave-Structure Interactions—Theory, Development, and Application." Journal of Marine Science and Engineering, 7: 81.

• Yingyi Liu, Changhong Hu, Makoto Sueyoshi, Hidetsugu Iwashita, Masashi Kashiwagi (2016). "Motion response prediction by hybrid panel-stick models for a semi-submersible with bracings." Journal of Marine Science and Technology, 21:742–757.

The deepwater Green function is using a fortran subroutine (https://github.com/Hui-Liang/Green-function-in-deep-water) developed by Dr. Hui Liang. For the detailed theory you may refer to the following three papers:

• Hui Liang, Huiyu Wu, and Francis Noblesse (2018). "Validation of a global approximation for wave diffraction-radiation in deep water." Applied Ocean Research, 74 : 80-86.

• Huiyu Wu, Hui Liang, and Francis Noblesse (2018). "Wave component in the Green function for diffraction radiation of regular water waves." Applied Ocean Research, 81: 72-75.

• Huiyu Wu, Chenliang Zhang, Yi Zhu, Wei Li, Decheng Wan, Francis Noblesse (2017). "A global approximation to the Green function for diffraction radiation of water waves." European Journal of Mechanics-B/Fluids, 65: 54-64.

The finite-depth Green function is using a fortran subroutine FinGreen3D (https://github.com/YingyiLiu/FinGreen3D) developed by Dr. Yingyi Liu. For the detailed theory you may refer to the following two papers:

• Yingyi Liu, Shigeo Yoshida, Changhong Hu, Makoto Sueyoshi, Liang Sun, Junliang Gao, Peiwen Cong, Guanghua He (2018). "A reliable open-source package for performance evaluation of floating renewable energy systems in coastal and offshore regions." Energy Conversion and Management, 174: 516-536.

• Yingyi Liu, Hidetsugu Iwashita, Changhong Hu (2015). "A calculation method for finite depth free-surface green function." International Journal of Naval Architecture and Ocean Engineering, 7(2): 375-389.

Please cite appropriately the above papers in your relevant publications, reports, etc., if the HAMS code or its executable program has contributed to your work.

Generated numerical results

- Hydrodynamic coefficients

- Wave excitation force

- Motion RAOs

- Free-surface elevation

Features

- Mesh element type

• HAMS can import meshes containing triangular panel type, quadrilateral panel type, or both.

- OpenMP parallel processing

• HAMS can be run in the parallel mode using OpenMP techniques on PC's with multiple processors (CPU's).

- Computational efficiency

• The following graph shows an example of DeepCwind semisubmersible using 8 threads for the computation:

Useful Links

The following open-source software can be used to view the HAMS results:
[1]. BEMRosetta. Developed by Iñaki Zabala, Markel Peñalba, Yerai Peña-Sanchez.
[2]. BEMIO. Developed by National Renewable Energy Laboratory and Sandia National Laboratories.

You may need HAMS to do the frequency-domain pre-processing before you use the following programs:
[1]. FAST or OpenFAST. Developed by National Renewable Energy Laboratory.
[2]. WEC-Sim. Developed by National Renewable Energy Laboratory and Sandia National Laboratories.

Used by other open-source software:
[1]. pyHAMS. Developed by Garrett Barter, National Renewable Energy Laboratory.
[2]. RAFT. Developed by Matt Hall, Stein Housner, David Ogden, Garrett Barter, National Renewable Energy Laboratory.

License

Code original author: Yingyi Liu (劉盈溢), Google Scholar.

HAMS is free software: you can redistribute it and/or modify it under the terms of the Apache License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version.

HAMS is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the Apache License for details. You should have received a copy of the Apache License along with HAMS. If not, see http://www.apache.org/licenses/LICENSE-2.0