1. Data Group A: General Control Data

General inputs include the unit system.

1.1. INPMOD identification text

An identification text describing the INPMOD run may be given. If given, this text is printed on the front page of the INPMOD print file.

1.1.1. Data group identifier, one input line

Mandatory. ~ INPMod IDENtification TEXT CHVERS ~ - CHVERS: character(8): RIFLEX input file version, e.g. 3.2

1.1.2. Identification text, three input lines

Mandatory. ~ Heading, line no 1 Heading, line no 2 Heading, line no 3 ~

Always three input lines, which may all be blank. Each line may contain up to 60 characters.

1.2. Selection of unit system physical constant

The program applies a set of consistent units. The user is free to select any combination of unit names for:

  • time \([\mathrm T]\)

  • length \([\mathrm L]\)

  • mass \([\mathrm M]\)

  • force \([\mathrm F]\)

1.2.1. Data group identifier, one input line

Mandatory. ~ UNIT NAME SPECification ~

1.2.2. Unit names and gravitational constant

Mandatory. ~ UT UL UM UF GRAV GCONS ~

  • UT: character(6), default: "s": Unit name for time

  • UL: character(6), default: "m": Unit name for length

  • UM: character(6), default: "kg": Unit name for mass

  • UF: character(6), default: "kN": Unit name for force

  • GRAV: real > 0, default: 9.81: Numerical value of gravitational constant \([\mathrm {L/T^2}]\)

  • GCONS: real > 0, default: 0.001: Consistency acceleration parameter.

    • GCONS = ACC[UF/UM]/ACC - where ACC is the numerical value of acceleration with the force and mass units, and with the length and time units, respectively. - With a consistent set of units, GCONS = 1.0.

Example: For the default units, the acceleration of gravity is \(9.81\times 10^{-3}\,\mathrm {kN/kg}\) or \(9.81\,\mathrm {m/s}^2\) and GCONS may be calculated as \(\mathrm {9.81\times 10^{-3}/9.81=0.001}\).

In the case of GCONS \(\mathrm {\neq 1}\), the calculation of drag force coefficients must be multiplied by GCONS, for example CDY = GCONS\(\mathrm {(\frac{1}{2}\rho C_DD)}\), see also Hydrodynamic force coefficients.

The unit names are printed as an output heading as shown below.

       +--------------------------------------------------------+
       !     CONSISTENT UNITS USED THROUGHOUT THE ANALYSES      !
       !--------------------------------------------------------!
       !     NAME FOR TIME   :  T = s                           !
       !     NAME FOR LENGTH :  L = m                           !
       !     NAME FOR MASS   :  M = kg                          !
       !     NAME FOR FORCE  :  F = kN                          !
       !                                                        !
       !     GRAVITATIONAL CONSTANT :                           !
       !     G     =  9.810     L/T**2                          !
       !     CONSISTENCY ACCELERATION PARAMETER :               !
       !     GCONS = 0.1000E-02 (F/M)/(L/T**2)                  !
       +--------------------------------------------------------+

1.3. Termination of input data

As mentioned an INPMOD run consist of some of the data groups A, B, C, D, E and F. No termination is to be provided between the data groups, but after the last data group is given, the following input line must be given to terminate the input stream:

END