1. STWAVE Usage & Theory
Taylor Asher

2. Presentation Introduction Theory Numerical discretization Input/Output
Wave action
Wave spectrum
Numerical discretization
Input/Output
Input files
Model parameters
Wave spectrum, wind, water level
Output files
Selected wave parameters
Wave parameter fields
Application

3. Theory Model assumptions Mild bottom slope, negligible reflection
Spatially homogeneous offshore (boundary)
Steady-state formulation
Linear refraction & shoaling
Depth-uniform current
Frictionless bottom
Linear radiation stress

4. Wave Action Steady-state conservation of spectral wave action NOTE
sum of sources and sinks
speed of propagation of wave packet
wave phase speed
kinetic+potential, per unit surface area
self-explanatory
relative to reference axis

5. Wave spectrum

6. Wave spectrum
Bretschneider-Mitsuyasu spectrum, with peak frequency fp, and wind speed U
with

7. Wave spectrum
Directionalized spectrum, with magnitude-normalized directional term
with normalization term

8. Numerical discretization
Domain is made of a grid of NI by NJ square cells, Δx in length, with locally-defined axes
Waves start at I=1, propagating toward I=NI
No backward-propagation
35 angular bins ±87.5o

9. Input/Output

10. Input files Model parameters (options.std)
IPRP: Switch for source/sink terms, such as wind waves, wave-wave interactions
ICUR: Switch for current
IBREAK: Switch for printing wave breaking
IRS: Switch for calculating radiation stress gradient
NSELCT: Number of special output points; 2-D wave spectra are generated for these points
Points: (I,J) pairs for each point.

11. Input files Wave spectrum, wind, water level (spec.in)
NF: Number of frequency bins
NA: Number of direction bins (must be 35)
Frequency vector of length NF, ordered smallest to largest (Hz)
IDD: Integer event identifier
U: Wind speed (m/s)
UDIR: Wind direction (degrees)
FM: Peak spectral frequency (Hz)
DADD: Water elevation correction
Wave spectrum (m2/s/Hz), ordered lowest frequency & -85 deg to 85 deg, to highest frequency -85 to 85

12. spec.in NF=25 NA=35 IDDD=200700 U=15 m/s UDIR=10 deg. FM=0.07 Hz
DADD=-1 m

13. Output files Selected wave parameters (selhts.out)
IDD: Integer event identifier (from spec.in)
I: Integer x-grid cell index
J: Integer y-grid cell index
N: Integer number of point (points are 1 to NSELCT
Hm0: Zeroth-moment (significant) wave height at cell (I,J) in meters
Tp: Peak wave period at cell (I,J) in seconds
αm: Mean wave direction at cell (I,J) in degrees

14. Output files Wave parameter fields (wavfld) NI, NJ: Grid dimension
DXINC: Grid spacing
IDD: Integer event identifier (as before)
Wave height for each cell in wave field, ordered in the cross-shore direction from (1,NJ) to (NI,NJ), to (1,1) to (NI,1)
Wave period for each cell in wave field, same ordering
Wave direction for each cell in wave field, same ordering