Presentation by Jay Veeramony, US Naval Research Laboratory, USA, at the Delft3D - User Days (Day 2: Sediment transport and morphology), during Delft Software Days - Edition 2017. Tuesday, 31 October 2017, Delft.

1. Predicting evolution of bathymetry at
Duck, NC
Jay Veeramony, Allison Penko
Naval Research Lab, Stennis Space Center, Mississippi

2. Delft3D User Days 2017| 2U.S. Naval Research Laboratory
Duck, NC: Army Corp of Engineers Field Research Facility (FRF)
• Sandy beach, alongshore uniform
• Wave activity/wave driven currents
• Morphologically dynamic
• First experiments conducted in 1982 – frequent surveys,
constant wave monitoring and more recently currents

3. Objective & Motivation:
To simulate daily hydrodynamic (and morphodynamic)
conditions in near real-time with Delft3D as part of the Coastal
Model Test Bed (CMTB) project.
The CMTB provides an automated evaluation of coastal
numerical models utilizing near real-time observations output by
the US Army Corps of Engineers Field Research facility in
Duck, NC to:
• assess model parameterizations over range of conditions
• Identify conditions/areas of increased model performance
• provide framework to develop data assimilation techniques
• Give accurate initial/boundary conditions for forecasting hazardous
conditions due to extreme events

4. Nested Grid 1.2km x 3.2km
5m x 20m grid cells
241x161
Parent Grid 3.7km x 12km
50m x 100m grid cells
75x121
6m AWAC
Coastal ImagingTower
Coastal Model Test Bed (CMTB)
Simulate daily hydrodynamic (and morphodynamic)
conditions in near real-time at Duck, NC, USA, with
Delft3D

5. Nested Grid 1.2km x 3.2km
5m x 20m grid cells
241x161
Parent Grid 3.7km x 12km
50m x 100m grid cells
75x121
🔵
🔵
🔵6m AWAC
Coastal ImagingTower🔵
🔵
Utilize near real-time
observations output by the
US Army Corps of Engineers
Field Research facility in
Duck, NC to:
• assess model parameterizations over a
range of environmental conditions
• Identify conditions/areas of increased
model performance

6. U.S. Naval Research Laboratory

7. Nested Grid 1.2km x 3.2km
5m x 20m grid cells
241x161
Parent Grid 3.7km x 12km
50m x 100m grid cells
75x121
🔵
🔵6m AWAC
Coastal ImagingTower🔵
🔵
🔵

8. Real-time model framework
Get Data
• Download netcdf from THREDDS
• Make Delft3D BC’s
RunDelft3D
• Run Delft3D FLOW-WAVE-MOR
Post-process
• Automated output analysis
• Archive results

9. Model setup
• Simulation period – Oct 8 – Oct 8, 2015
• Wave domain:
• Outer domain – 50m x 100m, Inner domain – 5m x 20m
• Outer domain forced with wave spectra from 17m buoy along the offshore
boundary
• Flow domain:
• 5m x 20m resolution, contained within inner wave domain
• Neumann boundary conditions at North and South boundaries
• Water level = 0 at the offshore boundary
• Model parameters:
• Manning’s n = 0.03
• Morphology:
• Defaults used except SusW=BedW=0.1 for 2D; =0.5 for 3D

10. Wave simulation Results

11. U.S. Naval Research Laboratory
Delft3D-Observation Comparison (Waves)

12. U.S. Naval Research Laboratory
Delft3D-Observation Comparison (Waves)
* Pressure-gage array data (NOT
AWAC)

13. U.S. Naval Research Laboratory
Delft3D-Observation Comparison (Waves)

14. U.S. Naval Research Laboratory
Modeled Change in morphology (2D)
Morphology model setup:
• D50: 0.025 cm
• Initial sediment layer thickness: 10 m
• Morphology scale factor: 1
• Initial Bathymetry: Oct 2, 2015
• Final Bathymetry: Oct 8, 2015

15. U.S. Naval Research Laboratory
Modeled Change in morphology (3D)
Morphology model setup:
• 10 vertical sigma layers
• D50: 0.025 cm
• Initial sediment layer thickness: 10 m
• Morphology scale factor: 1
• Initial Bathymetry: Oct 2, 2015
• Final Bathymetry: Oct 8, 2015

16. U.S. Naval Research Laboratory
Model (2D) – data comparison

17. U.S. Naval Research Laboratory
Model (3D) – data comparison

18. Summary
• Coupled FLOW-WAVE-MOR simulations setup at Duck, NC for
monitoring.
• Data collected and published by Army Corps of Engineering in near
realtime
• Wave model compares well with data
• Large changes along the shoreline compared to data
• Issues with model parameters?
• Bulk parameters defining sediment need validation
U.S. Naval Research Laboratory