Tuflow and estry manual Version 3

Read MI Table Links == <.mif/.mid_file> 50

Read Materials File == 51

Relative Resistance == [ {RELATIVE} | MATERIAL ] 51

S Channel Approach == [ PRE 2004-06-AA ] 51

Storage Above Structure Obvert == [ {CHANNEL WIDTH} | ] 51

Trim XZ Profiles == [ ON | {OFF} ] 52

XS Database == 52

[ BG | CS | NA | VG ].... ! Fixed Field Flags 60

BG Data == 60

CS Data == 60

NA Data == 61

VG Data == 61

Read MI IWL == <.mif/.mid_file> 69

Set IWL == 69

BC Database == <.csv_file> 77

BC Event Name == 77

BC Event Text == 78

EB Data == 78

Read MI BC == <.mif/.mid_file> 78

Cell Size == 9

Grid Size (N,M) == , 9

Grid Size (X,Y) == ,  9

Orientation == , 9

Orientation Angle == 10

Origin == , 10

Read MI Location == <.mif/.mid_file> 10

Read TGA == <.tga_file> 18

Read TGF == <.tgf_file> 18

External Bndy == , , , 27

Read MI [ MAT | IWL | CnM | FRIC | WrF | FLC ] == 28

Read MI Code [ {} | BC ] == 28

Read MID [ CODE | MAT | IWL | CnM | FRIC | WrF | FLC ] == 28

Read MID Grid == 29

Set [ CODE | MAT | IWL | CnM | FRIC | WrF ] == 29

Write MI Domain == <.mif/.mid_file> 29

Write MI Grid == <.mif/.mid_file> 29

Allow Dangling Z Lines == [ ON | {OFF} ] 38

Default Land Z == 38

Interpolate ZC [ {} | ALL ] [ {} | LOWER ] 38

Interpolate [ ZHC | ZUVC ] [ {} | ALL ] [ {} | AFTER ] 39

Pause When Polyline Does Not Find Zpt == [ ON | {OFF} ] 39

Read MI Z Line [ {} | RIDGE or MAX | GULLY or MIN | HX ] [ {} | CC ] [ {} | THICK ] [ {} | ADD ] == 40

Read MI Zpts [ {} | ADD | MAX | MIN ] == 41

Read MID Zpts [ {} | ADD | MAX | MIN ] == 41

Set Zpt == 42

Write MI Zpts == 42

ZC == MIN(ZU,ZV) 42

Read File == 51

Stop 51

BC Database == <.csv_file> 9

BC Event Name == 9

BC Event Text == 10

Global Rainfall Area Factor == [ {1.0} | ] 10

Global Rainfall BC == 10

Global Rainfall Continuing Loss == [ {0} | ] 10

Global Rainfall Initial Loss == [ {0} | ] 10

Read MI BC == <.mif/.mid_file> 10

Read MI SA [ {} | Rainfall ] == <.mif/.mid_file> 11

Unused HX and SX Connections == [ {ERROR} | WARNING ] 11

Bridge Flow == [ {Method A} | Method B ]

(1D & 2D/1D. Optional)

Controls the method for calculating bridge flows. Method A uses the original ESTRY bridge routine. Method B, introduced at Build 2005-05-AN, is based on Method A, but provides improved stability particularly when the bridge is flowing at shallow depths or is wetting and drying. Method B also does not force the loss coefficient to be a minimum of 1.5625 once the bridge obvert is surcharged (Method B uses the value as specified in the BG table). Testing of Method B indicates that it is the preferred approach, however, Method A has been left as the default for backward compatibility. It is intended to make Method B as the default in a future release once further testing has been carried out.

Culvert Flow == [ Method A | {Method B} ]

(1D & 2D/1D. Optional)

Controls the method for calculating culvert flows. Method A is the original ESTRY culvert routines. Method B, first incorporated at Build 2002-07-AC, is an adaptation of Method A to include new regimes K and L (see Section ). Method B also offers improved stability, smoother transitions between flow regimes and corrects very occasional mass conservation errors under certain flow regimes. As of Build 2002-08-AD, the default approach is Method B. Prior to this build, Method A was the default. Method A will always remain available for backward compatibility.

End Time ==

(1D Only. Mandatory)

Specifies the finish time of the simulation in hours. Value must be greater than the start time and can be negative.

Froude Check == [ {1} | ]

(Optional)

Sets the minimum Froude Number that upstream controlled friction flow may occur in “S” channels. Improved stability may occur in steeply flowing areas if is less than 1. cannot be below zero and would normally not exceed 1.

Froude Depth Adjustment == [ {ON} | OFF ]

(Optional)

Switches on or off an additional upstream controlled friction flow check for S channels incorporated in Build 2003-01-AF (a similar check is used for 2D domains – see Section 3.14.3). Set to OFF for backward compatibility for models run prior to Build 2003-01-AF that use the upstream controlled friction feature (ie. “S” channels).

Head Rate Creep Factor == [ | {1.2} ]

(1D & 2D/1D Only. Optional)

Specifies rate at which the Head Rate Limit value changes.

Head Rate Limit == [ ON | {OFF} | ]

(1D & 2D/1D Only. Optional)

Specifies the head rate limit applied to nodes. This feature can be used to stabilise problematic 1D nodes, but should be used with caution and mass balance checks made to ensure there is no significant mass loss or gain. It is particularly useful where a node “bounces” temporarily and is prevented from becoming unstable. The maximum amount the water level can change in half a timestep is the value after any adjustment by the Head Rate Creep Factor. The is adjusted up and down depending on the stability of the node in a similar approach used for Vel Rate Limit. If the ON option is used, the value is set to 0.1.

Head Rate Limit Minimum == [ | {0.001} ]

(1D & 2D/1D Only. Optional)

Specifies the minimum head rate limit that can occur. See Head Rate Limit.

Start Time ==

(1D Only. Mandatory)

Specifies the start time of the simulation in hours. Value can be negative and it is recommended that it be relative to midnight for historical events.

Structure Losses == [ ADJUST | {FIX} ]

(1D & 2D/1D Only. Optional)

If set to ADJUST, the entrance and exit losses of culverts and the bridge loss coefficients are adjusted according to the approach and departure velocities upstream and downstream of the structure. See Section 3.14.4.1 for details. Introduced in Build 2005-05-AN (set to FIX for backward compatibility).

Timestep ==

(1D & 2D/1D Only. Mandatory for 1D only.)

Specifies the computation timestep of the simulation in seconds. Value must be greater than zero. Timesteps that divide equally into one minute are recommended. For example, 0.5, 1, 2, 3, 5, 6, 7.5, 10, 12, 15, 20, 30, 45, 60, etc. seconds.

As of Build 2005-05-AN, this command can be specified for 2D/1D models and can be different to the timesteps of the 2D domains, but must not be greater than the smallest timestep of the 2D domains. If the 1D timestep is not equally divisible into the smallest 2D timestep, the 1D timestep is reduced automatically so that it is equally divisible. If this command is not specified in the .ecf file, the smallest 2D timestep is used.

Vel Rate Creep Factor == [ | {1.2} ]

(1D & 2D/1D Only. Optional)

Specifies rate at which the Vel Rate Limit value changes. This value is rarely changed from its default value of 1.2. See Vel Rate Limit for further discussion.

Note, in early versions of TUFLOW, this command was referred to as just Creep Factor.

Vel Rate Limit == [ | {0.2} ]

(1D & 2D/1D Only. Optional)

Specifies the velocity rate limit applied to non-inertial channels (structures). This value is rarely changed from its default value of 0.2. During a computation this value is adjusted downwards if a structure becomes unstable and upwards if stable using the Creep Factor value. In Build 2003-07-AF, an “L” is shown in the second space after velocity and flow time output in the .eof file, and also in the _TSF.mif output, indicating if the velocity rate limit algorithm was applied (previous builds used an asterisk (“*”)). If a structure frequently has the velocity rate limit applied to it, checks should be made on structure configuration and on the results at the structure.

Vel Rate Limit Minimum == [ | {0.0001} ]

(1D & 2D/1D Only. Optional)

Specifies the minimum velocity rate limit that can occur. See Vel Rate Limit. Prior to Build 2003 08 AD, the velocity rate limit could, in rare cases, reach zero and “freeze” the structure, giving unrealistic results.