Output File   

In the Output File dialog you specify the output file name and folder where to place the data file. If the output file already exists you can view the selected data file using the MIKE Zero Time Series editor by clicking on the "View" but­ton.

Parameters

For the auto, incident and reflected wave spectra the following parameters are calculated:

·         significant wave height, H_m0

·         mean wave periods T₀₁ and T₀₂

·         spectral peak period T_p

·         spectral width e₄

·         average reflection coefficient C_R

A number of the parameters are based on the spectral moments:

(8.2)   

·         significant wave height defined as

(8.3)   

·         mean wave periods defined as

(8.4)   

·         spectral peak period defined as

(8.5)   

where f_p is the frequency corresponding to the maximum spectral den­sity.

·         spectral width or broadness parameter defined as

(8.6)   

·         Average reflection coefficient is always given in the log file for the analy­sis. The average reflection coefficient is defined by:

(8.7)   

where S_R(f) and S_I(f) are reflected and incident spectrum, respectively.

A number of calculated parameters and functions are related to the perfor­mance of the AWACS system:

·         re-reflection function (only available in absorption mode)

·         generation function (only available in absorption mode)

·         coherence (only available in absorption mode)

·         wavemaker group delay and AWACS servo delay

The definition and interpretation of these are:

·         the wavemaker group delay is calculated from desired and actual paddle positions and given as a frequency dependent phase shift. The AWACS servo delay is determined from the wavemaker group delay as a weighted fit within the primary working range of the wavemaker. For opti­mal performance of the AWACS system the delay must be close to 50ms.

·         the re-reflection function is defined as the additional amplitude of waves emitted from the wavemaker due to reflections divided by the reflected wave amplitude at a given frequency. Practical and theoretical functions may be compared.

·         the generation function is defined as the ratio of the generated and desired wave amplitude in case of no reflection. Practical and theoretical functions may be compared.

·         the coherence spectrum is the fraction of the reflected time series of sur­face elevations that is linearly due to the incident time series of surface elevations. The AWACS system is based on linear wave theory and the coherence should generally be close to unity.

Log file

As default the log file is automatically opened after model execution. The file is opened in Notepad.