Current

By default the current data is set to be included in the warm up and warm down durations as specified on the Time dialog.

When a current field is included, it can be provided in 2 ways:

·         Speed and direction

·         (u,v) components

If providing the current field as Speed and direction, the direction is inter­preted as clockwise positive from true north (going to) as seen in Figure 1.12.

Figure 1.12        Interpretation of directional current data

If providing the current as (u,v) components, the components are interpreted as being with respect to the x and y axes of the domain file. This means you might have to ensure the directions of the components match the grid orienta­tion, dependent on the source used for current data.

Regardless of how the current field is given, both of these formats are sup­ported:

·         Varying in time, constant in domain (.dfs0) (time series)

·         Varying in time and domain (.dfs2) (current field)

At the bottom of the Current dialog, you are to enter drag coefficients for Rear and Front of each vessel, if specifying the current field in (.dfs2) format.

The Drag coefficients are dependent on the Water depth/Draft ratio, and the recommended values are as shown in Table 1.1.