Dynamic Current Variation

  • The current velocity and direction have to be specified at all levels defined in the preceding static analysis.

  • The static current profile is interpreted as the current profile at time equal to zero.

  • The dynamic current profile is described at an arbitrary number of time instants, given by increasing values. Linear interpolation is used for intermediate values.

  • If the last defined time instant is exceeded during simulation, the current profile is assumed constant and equal to the last specification for the continued simulation.

1. File format

1.1. Number of specified time instants, one input line

NDYCUR
  • NDYCUR: integer > 1: The number of time instants for which current profile is given.

The input data in Number of levels and time instant, one input line and Current velocity and direction, one input line per current level, i.e. NLCUR input lines (below) must be given in one block for each defined time instant.

1.2. Number of levels and time instant, one input line

NLCUR TIMDCU
  • NLCUR: integer: Number of levels in current profile. The number of levels has to be equal the number used in the preceding static analysis

  • TIMDCU: real > 0: Time instant for the specified current profile \(\mathrm {[T]}\)

1.3. Current velocity and direction, one input line per current level, i.e. NLCUR input lines

CURDIR CURVEL CURVEZ
  • CURDIR: real: Direction of current velocity.

    • The angle is measured in degrees from global x-axis counter clockwise to the current vector, confer Current parameters

  • CURVEL: real, default: 0: Current velocity \(\mathrm {[L/T]}\)

  • CURVEZ: real, default: 0: Vertical current velocity \(\mathrm {[L/T]}\)

2. Example

The number of levels has to be equal the number used in the specified static analysis. In the example below, three levels are defined in the static analysis and the same number of levels is defined in the dynamic current profile.
'--------------------------------------------------------
' ndyncur = number of time instants
' ndyncur
  6
'--------------------------------------------------------
' NLCUR = Number of levels in current profile.
' TIMDCU = Time instant for the specified current profile
' nlcur   timdcu
'---------------------------------------------------------
  3       10.0
' curdir  curvel  curver
  0.      0.0     0.0
  0.      0.0     0.0
  0.      0.0     0.0
'---------------------------------------------------------
' nlcur   timdcu
  3       50.0
' curdir  curvel  curver
  0.      0.0      0.0
  0.      0.0      0.0
  0.      0.0      0.0
'---------------------------------------------------------
' nlcur   timdcu
  3       100.0
' curdir  curvel  curver
  0.      1.0      0.0
  0.      1.0      0.0
  0.      0.0      0.0
'---------------------------------------------------------
' nlcur   timdcu
  3       150.0
' curdir  curvel  curver
  0.      1.0      0.0
  0.      1.0      0.0
  0.      0.0      0.0
'---------------------------------------------------------
' nlcur   timdcu
  3       200.0
' curdir  curvel  curver
  0.      0.0      0.0
  0.      0.0      0.0
  0.      0.0      0.0
'---------------------------------------------------------
' nlcur   timdcu
  3       300.0
' curdir  curvel  curver
  0.      0.0      0.0
  0.      0.0      0.0
  0.      0.0      0.0
'---------------------------------------------------------