Single vessel + sediment (small domain for training session)

In this example, you will add sediment morphology to a single vessel ship wakes example. The primary “input.txt” and vessel_00001 files are located in /simple_cases/single_vessel_short_channel/work/.

Model setup

alternate text

NOTE: the simulation is performed in a half domain: y = 0 – 60 m

Setup in “input.txt”

Set a descriptive title for your simulation:

!-----TITLE-----
 TITLE = vessel_sediment

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

!-----PARALLEL INFO-----
 PX = 2
 PY = 1

Set the bathymetry to the provided depth file; comment out all other depth parameters:

!-----DEPTH-----
 DEPTH_TYPE = DATA
 DEPTH_FILE = ../bathy/depth.txt

(refer to Grid and Computational Time for parameter definitions)

Send the results to a folder named “output”:

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

Set the dimension of the domain to 400 x 60 (x and y directions, respectively):

!-----DIMENSION-----
 Mglob = 400
 Nglob = 60

Set the computational time, plot time, station printing interval, and screen interval to 60.0 s, 2.0 s, 0.1 s, and 2.0 s, respectively:

!-----TIME-----
 TOTAL_TIME = 60.0
 PLOT_INTV = 2.0
 PLOT_INTV_STATION = 10000.0
 SCREEN_INTV = 2.0

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

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

Add single vessel with the following characteristics:

!-----SHIP WAKES-----
 VESSEL_FOLDER = ./
 NumVessel = 1

You need a vessel file vessel_00001 in the current folder. In vessel_00001, specify:

Title: Vessel # 1
Blue_Star_I
Length(m), Width(m), Alpha(0.5), Beta(0.5), P(draft,m)
10.0  5.0, 0.5, 0.5, 1.5
Time, X(m), Y(m)  (relative to the orgin of the coordinates)
0.0   40.0   60.0
25523.0  180040.0  60.0

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

Set the sponge layer parameters to the following:

!-----SPONGE LAYER-----
 FRICTION_SPONGE = T
 DIRECT_SPONGE = T
 Csp = 0.10
 CDsponge = 10.0
 Sponge_west_width =  0.0
 Sponge_east_width =  0.0
 Sponge_south_width = 0.0
 Sponge_north_width = 0.0
 R_sponge = 0.85
 A_sponge = 5.0
 ETA_LIMITER = F

Set the following PHYSICS and WET-DRY parameters to the following:

!-----PHYSICS-----
 VISCOSITY_BREAKING = T
 Cd = 0.0
 CFL = 0.5
 FroudeCap = 10.0

!-----WET-DRY-----
 MinDepth = 0.02
 Cbrk1 = 0.70
 Cbrk2 = 0.40

Add DEPTH_OUT, U, V, ETA, and MASK to the output:

!-----OUTPUT-----
 DEPTH_OUT = T
 U = T
 V = T
 ETA = T
 MASK = T

Add the sediment morphology parameters:

!-----SEDIMENT-----
 Bed_Change = T
 BedLoad = T
 D50 = 0.0005
 Sdensity = 2.68
 n_porosity = 0.47
 WS = 0.0125
 Shields_cr = 0.055
 Shields_cr_bedload = 0.047
 Tan_phi = 0.7
 Kappa1 = 0.3333
 Kappa2 = 1.0
 MinDepthPickup = 0.1

(refer to Sediment Transport and Morphological Change for sediment parameter definitions)

Postprocessing

For postprocessing examples, MATLAB and Python scripts are located in /simple_cases/single_vessel_short_channel/postprocessing/. An example model result is shown below:

alternate text

Fig. 11 (Top) surface elevation, (middle) sediment concentration, (bottom) bed change