Two vessels with different speeds

The first example of adding vessel dynamics is for two vessels with different speeds over a flat bottom. The primary “input.txt” and vessel files are located in simple_cases/vessel_flat_bottom/. Refer to Ship-wake Module for a review of vessel types.

Model setup

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Setup in input.txt:

Set a descriptive title for your simulation:

!-----TITLE-----
 TITLE = vessel_flat

If running in parallel, set the number of processors in X and Y:

!-----PARALLEL INFO-----
 PX = 4
 PY = 1

Set the bathmetry to a flat bottom of depth 10.0 m:

!-----DEPTH-----
 DEPTH_TYPE = FLAT
 DEPTH_FLAT = 10.0

(refer to Grid and Computational Time for parameter definitions)

Send the results to a folder named “output”:

!-----PRINT-----
 RESULT_FOLDER = output/

Set the dimensions of the domain to 500 X 100 (x and y directions, respectively):

!-----DIMENSION-----
 Mglob = 500
 Nglob = 100

Set the total computation time, plot time, station print interval and screen interval to 50.0 s, 1.0, 50,000.0 s, and 1.0 s, respectively:

!-----TIME-----
 TOTAL_TIME = 50.0
 PLOT_INTV = 1.0
 PLOT_INTV_STATION = 50000.0
 SCREEN_INTV = 1.0

Set the grid spacing in x and y to 1.0 m:

!-----GRID-----
 DX = 1.0
 DY = 1.0

Instead of adding a wavemaker, you will add the number of vessels to include and the path to the vessel files:

!-----SHIP WAKES-----
 VESSEL_FOLDER = ./
 NumVessel = 2

You will need two vessel files: vessel_00001 and vessel_00002 in the working folder. In vessel_00001, specify:

Title: Vessel # 1
Pressure, 1
Length(m), Width(m), Alpha1(0.5),Alpha2(0.5), Beta(0.5), P(draft,m)
10.0  5.0, 0.5, 0.5, 0.5, 2.0
Time, X(m), Y(m)  (relative to the orgin of the coordinates)
0.0   50.0   40.0
100.0 1050.0 40.0

In vessel_00002, specify:

Title: Vessel # 2
Pressure, 1
Length(m), Width(m), Alpha1(0.5),Alpha2(0.5), Beta(0.5), P(draft,m)
20.0  8.0, 0.5, 0.5, 0.5, 3.0
Time, X(m), Y(m)  (relative to the orgin of the coordinates)
0.0   450.0   60.0
100.0 -50.0   60.0

(refer to Ship-wake Module and Shipwakes for more information)

Set the ETA output parameter to true:

!-----OUTPUT-----
 ETA = T

Postprocessing

For postprocessing examples, MATLAB and Python scripts are located in /simple_cases/vessel_flat_bottom/. Using plot_wave_vessel.m the model result should look like the figure below.

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