Skip to content

Examples

OASIS includes a systematic test suite organised into 10 functional groups. Each group isolates a specific subsystem so that every feature can be tested independently. The examples also serve as working configurations you can adapt for your own projects.

Running Examples

cd examples
# Windows
run_all_examples.bat
# Linux
./run_all_examples.sh

cd examples/<group>
# Windows
run_group.bat
# Linux
./run_group.sh

cd examples/<group>/<test_name>
# Windows
run.bat
# Linux — from repo root
bin/oasis examples/<group>/<test_name>

Shared Data

Hydrodynamic databases are stored in examples/data/ and shared across examples:

File Bodies Used by
one_box.hydb.h5 1 box Most body/lines/springs examples
two_boxes.hydb.h5 2 boxes Multi-body examples
trl_plus.hydb.h5 1 platform Turbine examples
isobara_owcs.hydb.h5 7 (1 floater + 6 OWCs) OWC examples

These .hydb.h5 files are produced by SeaMotions, an open-source BEM solver by IHCantabria. Refer to the SeaMotions repository if you need to compute hydrodynamic databases for your own geometry.

Functional Groups

1. Body Behavior (body/)

Floating body dynamics: free decay, fixed/partial DOFs, imposed motion, radiation, excitation, nonlinear hydrostatics, and QTF (Quadratic Transfer Function).

Example Feature tested
free_decay Body released from offset, no waves
fixed All DOFs locked, wave forces measured
partial_dofs Subset of DOFs active
imposed_motion Prescribed motion from file
radiation Radiation force convolution
excitation_linear First-order wave excitation (linear)
excitation_instantpos Excitation at instantaneous position
nonlinear_hs_flat Nonlinear hydrostatics (flat water)
nonlinear_hs_waves Nonlinear hydrostatics with wave surface
qtf Second-order slow-drift forces

2. Wave Types (waves/)

Regular, irregular, and multi-directional seas.

Example Feature tested
regular Monochromatic regular wave
jonswap JONSWAP spectrum
jonswap_piecewise Piecewise-decomposed JONSWAP
multidirectional Multi-directional spreading
timeseries Wave from time-series file
frequency_domain Wave from frequency-domain file

3. Mooring Lines (lines/)

Dynamic mooring lines with varied configurations.

Example Feature tested
single_line Single catenary line
multi_line Multi-line spread mooring
joint_connection Lines connected via JointBCP
elastic_anchor Anchor with elastic spring
prescribed_motion Actuator-driven fairlead
viscoelastic Viscoelastic material model
tabulated_stiffness Tabulated force-strain curve
tension_symmetric Symmetric tension/compression
seabed_contact Ground contact model
friction_isotropic Isotropic seabed friction
friction_anisotropic Anisotropic seabed friction

4. Springs & Connectors (springs/)

Example Feature tested
pile_connector Pile-to-anchor spring with friction
neoprene_connector Body-to-body neoprene+wire connection

5. Wind Turbines (turbines/)

OpenFAST coupling.

Example Feature tested
fixed_turbine Turbine on fixed-foundation body
moored_turbine Turbine on moored floating platform

6. Oscillating Water Columns (owcs/)

Work in Progress

OWC examples are under active development.

Example Feature tested
free_decay OWC chamber free oscillation
excitation Wave excitation on OWC
hole_coupling Pneumatic coupling through orifice
turbine_coupling OWC with Wells/impulse turbine

7. Sinking (sinking/)

Example Feature tested
progressive_flooding Compartment flooding and sinking

8. Multi-Body (multibody/)

Example Feature tested
shared_hydb Two bodies from one multi-body HDB
separate_hydb Two bodies from individual HDBs

9. ODE Solvers (solvers/)

Comparison of integration methods on a cable with circular actuator motion.

Example Solver
bdf1 BDF order 1 (backward Euler)
bdfn_order2 BDF order 2
bdfn_order4 BDF order 4
esdirk46 ESDIRK 4th order, 6 stages

10. Winches (winches/)

Example Feature tested
horizontal_control Surge/sway/yaw positioning with state-space controller

Example Layout

Each example follows a standard structure:

<group>/<test_name>/
├── input/
│   ├── dataProblem.dat      # Simulation parameters
│   ├── dataBodies.dat       # Body definitions
│   ├── dataBCPs.dat         # Boundary condition points
│   ├── dataWaves.dat        # Wave configuration
│   └── ...                  # Optional subsystem files
├── output/                  # Created by OASIS
├── run.bat                  # Windows runner
└── run.sl                   # Linux/SLURM runner

YAML equivalents are available for some examples (e.g., free_decay_yaml/, fixed_yaml/).