Diffracted Wave Transfer Functions at Points

The file format is described in the following sections. An example is given at the end of this section.

1. File format

1.1. Data group identifier, one input line

FIRSt ORDEr DIFFracted wave transfer functions

1.2. Text describing the linear incoming wave to diffracted wave transfer functions, two input lines

TXDI1

  • TXDI1: character(60): Character string

1.3. Point reference, one input line

PTNOUS IVES

  • PTNOUS: integer: Point number defined by user

  • IVES: integer: Support vessel number

1.4. Point coordinates, one input line

XBDY YBDY ZBDY

  • XBDY: real: x-coordinate of where transfer function is calculated, given in support vessel coordinate system \(\mathrm {[L]}\)

  • YBDY: real: y-coordinate of where transfer function is calculated, given in support vessel coordinate system \(\mathrm {[L]}\)

  • ZBDY: real: z-coordinate of where transfer function is calculated, given in support vessel coordinate system \(\mathrm {[L]}\)

1.5. Dimensioning parameters, one input line

NDIR NFRE ITYPIN

  • NDIR: integer: Total number of wave directions (for this point)

  • NFRE: integer: Total number of frequencies (for this point)

  • ITYPIN: integer: Code for which format the transfer functions are given in

    • = 1: Complex form

    • = 2: Amplitude ratio \(\mathrm {[1]}\) and phase \(\mathrm {[deg]}\)

    • = 3: Amplitude ratio \(\mathrm {[1]}\) and phase \(\mathrm {[rad]}\)

1.6. Data identification, one input line

WAVE DIREctions DIFFracted wave transfer functions

1.7. Directions, NDIR input lines

IDIR DIR

  • IDIR: integer: Direction number (between 1 and NDIR)

  • DIR: real: Propagation direction of incoming wave \(\mathrm {[deg]}\)

1.8. Data identification, one input line

WAVE FREQuencies DIFFracted wave transfer functions

1.9. Frequencies, NFRE input lines

IFRE FRE

  • IFRE: integer: Frequency number (between 1 and NFRE)

  • FRE: real: Angular frequency of incoming wave \(\mathrm {[rad/T]}\)

1.10. Data identification, one input line

WAVE ELEVation DIFFracted wave transfer function

or

XVELocity DIFFracted WAVE transfer function
YVELocity DIFFracted WAVE transfer function
ZVELocity DIFFracted WAVE transfer function

1.11. Diffracted wave transfer function, NDIR x NFRE input lines

IDIR IFRE A B

  • IDIR: integer: Direction number

  • IFRE: integer: Frequency number

  • A: real: Interpretation according to value of ITYPIN

    • ITYPIN = 1: Real part

    • ITYPIN = 2: Amplitude ratio \(\mathrm {[1],[rad/m]}\)

    • ITYPIN = 3: Amplitude ratio \(\mathrm {[1],[rad/m]}\)

  • B: real: Interpretation according to value of ITYPIN

    • ITYPIN = 1: Imaginary part

    • ITYPIN = 2: Phase angle \(\mathrm {[deg]}\)

    • ITYPIN = 3: Phase angle \(\mathrm {[rad]}\)

Transfer functions for accelerations will be calculated based on velocity transfer functions.

2. Example

Download example file