Input Command Structure Each data group is preceded by an identification text line, such as SYSTem DESCription SIMO The uppercase (capital) letters must be written exactly as described, while the lowercase letters can be omitted. Lines starting with a hyphen ( ' ) are not read by SIMO, and can be used for comments. 1. File heading This data group is mandatory, is given in the start of the file, and can only be given once. 1.1. Start of file 1 input line. SYSTem DESCription SIMO 1.2. Text for identifying the system 3 input lines. TXSYS TXSYS: character(60): Character string describing the system. 1.3. Units and physical constants 1 input line. LENUNI TIMUNI MASUNI GRAV RHOW RHOA WAKIVI AIRKIVI LENUNI, character(8), default: "m": Length unit \(\mathrm {[L]}\) TIMUNI, character(8), default: "s": Time unit \(\mathrm {[T]}\) MASUNI, character(8), default: "Mg": Mass unit \(\mathrm {[M]}\) GRAV, real, default: 9.81: Acceleration of gravity \(\mathrm {[L/T^2]}\) RHOW, real, default: 1.025: Mass density of water \(\mathrm {[M/L^3]}\) RHOA, real, default: 0.00125: Mass density of air \(\mathrm {[M/L^3]}\) WAKIVI, real, default: 1.188e-6: Kinematic viscosity of water \(\mathrm {[L^2/T]}\) AIRKIVI, real, default: 1.516e-5: Kinematic viscosity of air \(\mathrm {[L^2/T]}\) LENUNI, TIMUNI and MASUNI are dummy parameters, to be used as a reminder of the units used. GRAV, RHOW and RHOA must be positive. 1.4. 1 input line DEPTH DIRSLO SLOPE DEPTH, real, default: 100.0: Depth at global origin \(\mathrm {[L]}\) DIRSLO, real: Dummy SLOPE, real: Dummy 2. File termination 2.1. 1 input line that terminates reading of the file. END System Description File External Communication Specification