Wave kinematics test

This test checks the kinematics of the regular linear waves

1 Test description

In this test, the wave particle kinematics are checked at several locations within the wave field. Different combinations of wave height, wave period, wave angle and phase are tested. The following load cases are run
  • d = 20 m H = 6 T = 10 theta = 0 ph = 0 
  • d = 20 m H = 3 T = 10 theta = 0 ph = 0 
  • d = 20 m H = 3 T = 6 theta = 0 ph = 0 
  • d = 20 m H = 6 T = 10 theta = 0 ph = 90 
  • d = 20 m H = 6 T = 10 theta = 90 ph = 0 
  • d = 20 m H = 6 T = 10 theta = 45 ph = 0 
  • d = 20 m H = 6 T = 10 theta = -10 ph = 0

2 Model

This test uses the Monopile only template with the input file that can be downloaded from http://www.simis.io/downloads/open/Nightlies/Input_hydro_test/4_monopiles.txt
The CSV file can be downloaded from here: http://www.simis.io/downloads/open/Nightlies/Wave kinematic test.csv
The model is illustrated in the figure below:



The velocities and accelerations of a wave can be accessed via a Fluid kinematics sensor which is attached to a node. Therefore, to obtain kinematics at different locatins within the wave field, several monopiles are used in this test. The monopiles are at the following x-y coordinates: {0,0}, {3,0}, {0,3}, {3,3}. On each monopile, the kinematics are checked at two nodes at different heights: nodes 4 and 2, at -5 and -15 m below the seabed, respecitvely.
The water depth is 20 m.
The acceleration of gravity is 
$$g=9.80665\text{ m}\cdot\text{s}^{-1}$$
and the water density is 
$$d=1026.9\text{ kg}\cdot\text{m}^{-3}$$

3 Analytical solution

The particle velocity and acceleration for all 8 locations is computed based on linear wave theory in finite water depth. The equations used can be found in the Theory manual, in the Regular waves document.

4 Results

A simulation of 30 seconds is run for each load case. The resluts are considered passed if the values produced by Ashes are within the analytical solution +/- 0.5% of the maximum value of the analytical solution.
As an illustration, for the y-velocity of the first load case, this would correspond to the results being within the dotted lines in the figure below:




The report for this test can be found on the following link:

https://www.simis.io/downloads/open/benchmarks/current/Wave kinematic test.pdf