Overview

About this manual

This document is the User Manual for the TUFLOW FV hydrodynamic computational engine.

From the 2026.0.0 TUFLOW FV release, new features and changes between TUFLOW FV versions are provided centrally in the TUFLOW FV Changelog. Prior to this, detailed release documentation was published in individual Release Note documents. Documentation for all previous releases, including Changelogs, Release Notes and archived manuals, are available from TUFLOW Downloads Archive.

How to use this manual

This section provides an overview of the manual structure and the navigation features available to help locate information. These instructions are only provided in this section.

Structure

Model construction in TUFLOW FV follows a structured workflow. Readers should begin with the Architecture chapter, which introduces the organisational concepts used throughout the manual and explains the relationship between the model construction chapters and the supporting appendices. Subsequent model construction chapters describe the configuration of a specific simulation type. The recommended workflow is to start with Model Construction: 2D HD Simulation and then extend to additional simulation capabilities as required.

Within each model construction chapter, components are documented using a consistent structure. For each component, the documentation identifies whether it is required, conditionally required or optional, describes its purpose and outlines supported configuration approaches. Example syntax blocks are provided and may be copied directly into a TUFLOW FV control file.

Searching

The search function (top of the left sidebar) searches the entire manual, including chapters, tables, appendices and references. Matching results are displayed with a short preview of the surrounding text to help identify the relevant result before navigating to it.

Cross-references are used throughout the manual to link related content, including sections, figures, tables, equations, commands, etc. Hovering over a cross-reference displays a preview of the linked content. Selecting the link navigates directly to the referenced item.

The References chapter contains a complete list of all publications and resources cited throughout the manual.

Tables

Where appropriate, tables are searchable via the use of the search box, which is located at the top right of any search enabled table. Not all tables are searchable. When text is entered into the search box, table rows are dynamically filtered to only show those that contain the search text. This allows on-the-fly condensing of large tables so that only relevant content is presented.

Tables can be sorted alphabetically (or reverse alphabetically) with respect to any column by clicking (and re-clicking) the column headers. By default, all rows are displayed, however; the number of rows displayed is selectable via the ‘Show entries’ drop down. Undisplayed rows can be accessed by clicking Previous or Next or by using the numbered navigation boxes, all of which are located at the bottom of each searchable table.

Interactive Networks

Interactive networks are used to illustrate simulation architecture. Networks comprise of nodes connected by lines, with interactive features. Key points:

  • Nodes represent items within architectural levels.
  • Nodes are circular and coloured based on their architectural level:
    • simulation classes
    • model classes
    • model implementations
  • Architectural relationships are displayed as connecting directional lines, with each line’s colour matching that of its originating node

Below are some tips for interacting with networks:

  • Single click or hover over a node to highlight its nearest neighbours. Single clicking anywhere off the network will deselect these.
  • Use the Select by id drop down menu to select a particular node of interest. Its nearest neighbours will also be automatically selected.
  • Single click or hover over a legend entry to highlight all nodes of that type. Single clicking anywhere off the network will deselect these.
  • Single click, hold and drag a node to move it.
  • Single click, hold and drag white space anywhere within the activated network area to pan the entire network.
  • Use the mouse wheel to zoom in and out of the network.
  • Double click on any node that has the label starting text “Cluster on group :”. This will explode the nodes to see its containing subsidiary nodes.
  • Double click on any node within an exploded group to implode the group back to its original state.

Commands

Commands are displayed in highlighted text and are often provided as a clickable link to their corresponding command description in Appendix A — Commands.

The command appendix provides detailed descriptions of each command and its parameters. Each command includes a summary block containing key information such as status, relevant construction section links, required dependent commands, related commands, etc. Command parameters are then described either within individual sections or in tabulated form, depending on the complexity. The table of contents in the right sidebar provides a convenient way to browse commands and inputs/parameters within the appendix.

TUFLOW commands use a structured, colour-coded syntax that is consistent throughout the documentation.

Colour coding:

  • Blue: The command
  • Red: The operator (==)
  • Black: The input(s)/parameter(s)
  • Green: Comments (must be preceded by !)

A vertical bar (|) separates the different input options for a command. User defined values or parameters are enclosed in angled brackets (<>) and default values are enclosed in curly brackets ({}) or specified with the parameter.

For example, the following command has input options of either the default, 0, or 1 along with three user defined parameters <x_coord>, <y_coord>, <water_level>:

Auto Terminate == {0} | 1, <x_coord>, <y_coord>, <water_level>    ! command definition

Auto Terminate == 0                             ! default command input - used if the command is not specified

Auto Terminate == 1, 159.07365, -31.35875, 6.0  ! example user defined inputs

Example TUFLOW FV command file blocks are provided using highlighted text within scrollable code blocks. These blocks can be copied directly into a text editor when building a model control file. Comments to the right of each command summarise each argument value using the same syntax rules as defined above.

Select the icon in the upper right corner of the block to copy the entire command block to the clipboard.

Two example blocks are provided below:

! Global CFL With Timestep Limits
CFL == 0.95                                             ! {1.0} CFL Number
Timestep Limits == 0.5, 5.0                             ! {No default} Minimum Timestep (s), {No default} Maximum Timestep (s)
! Smagorinsky Model
Momentum Mixing Model == Smagorinsky                    ! {None} | Constant | Smagorinsky | Wu
Global Horizontal Eddy Viscosity == 0.5                 ! {0.0} Smagorinsky coefficient
Global Horizontal Eddy Viscosity Limits == 0.05, 99999. ! {0.0} Minimum eddy viscosity (m^2/s), {99999.} Maximum eddy viscosity (m^2/s)