Many tools exist to simulate dynamic systems in the time domain, with different focus and usage areas. FhSim focus on simulation performance and marine systems modelling. Models are most often developed in C++. An optional, integrated 3D visualisation facilitates model development and presentation purposes.

Features

FhSim is a software platform and framework for mathematical modelling and numerical simulation, with a focus on marine applications.

Fast Development

FhSim provides a common simulation environment in which models can be shared and combined in many different ways. This facilitates re-use, preserves project results, and cuts down on model development costs.

Extensive Model Library

FhSim features a large collection of mathematical models, including ships, trawl nets and doors, net cages, ropes and weight systems, buoys, cables, winches, and anchors.

Flexibility

FhSim can be run on Windows and Linux, as a stand-alone or as an API. It can be coupled with MATLAB/Simulink, and executed via Java (JNI).

High Realism

Models in FhSim are continuously validated against experimental data through projects employing FhSim as a tool. This ensures realistic model responses.

Speed and performance

FhSim is developed with performance and real-time applications in mind. FhSim is used for applications where performance is paramount, such as monitoring (state estimation), control systems (MPC), operational decision support and personnel training in virtual environments.

3D Visualization

FhSim features 3D visualization for development, demos, and presentation of results. Alternatively, it can also be run without visualization for maximum efficiency, e.g. when connected to external visualization engines.

Previous use cases

FhSim is in use in research, education, industry, and in training simulators. Here is a selection of past projects based on FhSim.
Sea cage
Full-scale sea cage in rough seas
Bottom trawling
Simulation of a bottom trawl system
Boat and net cage
Typical aquaculture operation with a boat and a net cage
Pitch damping with foils
Exploring optimal foil design and position to dampen vessel pitch movements
Fish farm
Simulation of a fish farm with multiple net cages
Trawl colliding with offshore pipeline
Evaluating the risk of trawl door snagging on offshore pipeline
State estimation
Improve inaccurate measurements using state estimation
Trawl impact on mooring
Analysis of trawl impact on mooring lines.
Structures in ice floe
Simulation of interactions between structures and ice floe
Vessel in ice (cosimulation)
Simulation of a vessel hull in ice, using cosimulation.
Digital twin of fish farm
Simulating a fish farm in real time, syncronised with the real farm using measurements.

Components

FhSim consists of several components which support different ways of use. Currently, the license terms are different for different parts of FhSim. Some are available for academic use, some for everyone and some only for paying customers. It is in the process of being made available for the public.

Executables

The FhSim executables can run simulations with and without visualisation and with or without real-time requirements. FhSim also has functionality for running parameter variations, is well-suited for sensitivity studies, as well as batch simulations.

Model libraries

The FhSim models are collected in precompiled libraries according to domain and license. Some models are publicly available, while other are available only to paying customers. Available for download here.

Co-simulation support

An FhSim simulation scenario can be exported into a co-simulation functional mock-up unit (FMU), following the FMI 2.0 standard. This allows you to connect your FhSim modelling effort with other simulators that support FMI co-simulation.

API

The FhSim API can be used for creating new simulation models and seamlessly integrate FhSim with your own software.

Expected available: July 2025

Source code

The source code for the FhSim API will be made available both as an assurance for the Ratatosk users, simplify development and to facilitate extending it as desired.

Expected available: To be determined

Support & Team

Meet the team behind FhSim in SINTEF Ocean.


Stian Skjong

Energy systems, co-simulation, state estimation and control


Biao Su

Marine aquaculture systems, ice-structure interactions


Karl-Johan Reite

FhSim core, net structures, trawl


Joakim Haugen

FhSim core, net structures, trawl


Andrei Tsarau

Hydrodynamics, sea loads, closed containment systems and net cages


Herman Biørn Amundsen

FhSim build system, FhSim core, net cages

Do you have any questions? Do you need support? Are you wondering how FhSim can be used in your project to help you reach your goals? Don't hesitate to contact us today!