2  Architecture

2.1 Overview

This chapter describes the architectural structure of TUFLOW FV and defines the organising framework used throughout the model construction chapters. The architecture establishes how simulation components are grouped, named and related, providing a consistent structure for locating commands, inputs and configuration options.

The content of this chapter is conceptual in nature and does not describe specific configuration steps or execution procedures. The material presented is intended to support understanding of the overall model structure, including how individual components relate to one another and how supporting information is distributed across chapters and appendices. Information required to configure and run simulations is provided in subsequent model construction chapters.

Instructions for the use of any interactive components included in this section are provided in the manual overview.

2.2 Simulation Tiers

A TUFLOW FV simulation is comprised of three simulation tiers as illustrated in Figure 2.1. Each TUFLOW FV simulation comprises:

  • Tier 1 — Simulation class: A user defined simulation class instance (Section 2.2.1)
  • Tier 2 — Model classes: A suite of model class instances associated with the simulation class (Section 2.2.2)
  • Tier 3 — Model implementations: A selected implementation for each model class instance (Section 2.2.3)
Figure 2.1: TUFLOW FV model architecture tiers

2.2.1 Tier 1: Simulation Class

A simulation class defines the type of TUFLOW FV model being constructed and the modelling objective it is intended to address. It determines which physical and numerical processes are active in the simulation and, by extension, which model components must be configured. The available simulation classes and their typical applications are summarised in Table 2.1, which can be used to identify the appropriate simulation class for a given modelling problem.

Table 2.1: TUFLOW FV simulation class instances
Simulation Class Instance Potential Uses

Two Dimensional Hydrodynamics (2D HD)

Simulation of 2D hydrodynamic use cases such as:

  • Storm tide or tsunami impact assessment
  • Astronomical tide modelling
  • Flooding and floodplain management

Three Dimensional Hydrodynamics (3D HD)

Simulation of 3D hydrodynamic use cases which do not require the simulation of salinity, temperature and density effects such as:

  • Rudimentary scour assessment
  • Hydraulic structure design
  • Flooding and floodplain management

Advection Dispersion (AD)

Simulation in 2D or 3D with salinity, temperature and/or non-transformative tracers for use cases such as:

  • Coastal and estuarine assessments
  • Lake hydrodynamics
  • Rudimentary tracer assessments

Sediment Transport (ST)

Simulation of coastal, estuarine, riverine, lake and catchment sediment transport processes for use cases such as:

  • Dredging and navigation management
  • Scour assessments
  • Channel design
  • Environmental impact assessment

Water Quality (WQ)

Simulation of coastal, estuarine, riverine, lake and catchment transformative water quality processes for use cases such as:

  • Disolved oxygen, inorganics and organic matter dynamics
  • Outfall impact assessment
  • Water supply and bathing waters
  • Aquaculture operations

Particle Tracking (PT)

Discrete particle tracking for use cases such as:

  • Environmental impact assessments
  • Rescue and salvage
  • Animal migration
  • Aquaculture operations

Simulation classes are cumulative: more advanced classes extend the capability of simpler classes, with the 2D Hydrodynamic (2D HD) simulation class providing the foundation for all other simulation classes. The dependency relationships between simulation classes are summarised in Table 2.2. Each simulation class has a corresponding model construction chapter.

Table 2.2: TUFLOW FV simulation class dependencies
Simulation Class Instance Simulation Class Dependencies

2D HD

Not applicable - 2D HD is the fundamental simulation class

3D HD

2D HD

AD

2D HD or 3D HD

ST

AD

WQ

AD or ST

PT

Can be run on any of the above simulation classes

2.2.2 Tier 2: Model Class

Each simulation class (Tier 1) is associated with a defined suite of model classes (Tier 2). For a given simulation class, individual model classes may be either required, conditionally required or optional, and this status is identified consistently throughout the model construction chapters. As simulation classes build on one another, the underlying model class suites expand, with model classes introduced in earlier simulation classes reused or extended in later classes.

Model classes represent discrete physical or numerical components of a simulation and form the primary organisational units of the model construction chapters. The model class suites associated with each simulation class are summarised in Table 2.3 and illustrated in Figure 2.3.

Table 2.3: TUFLOW FV simulation class instances and corresponding model class suites
Simulation Class Model Class Suite

2D HD

3D HD

2D HD Simulation Class plus:

AD

2D HD or 3D HD Simulation Class plus:

ST

AD Simulation Class plus:

WQ

AD or ST Simulation Class plus:

PT

Any of the above simulation classes plus:
Figure 2.2: TUFLOW FV simulation class and model class instance
Figure 2.3: TUFLOW FV simulation class and model class instance

2.2.3 Tier 3: Model Implementations

Model implementations (Tier 3) configure a model class (Tier 2). Each model class can select only one model implementation. Available model implementations are summarised in Table 2.4.

Table 2.4: TUFLOW FV model classes and available model implementations
Model Class Model Implementation

Coordinate Reference Frame
  • Cartesian (Metric Units)
  • Cartesian (US Customary Units)
  • Spherical (Metric Units)

Spatial Order (optional)
  • First Order
  • Second Order

Hardware (optional)
  • CPU
  • GPU

Simulation Time Settings
  • Hours
  • ISODate

Computational Timestep
  • Computational Timestep

Wetting And Drying (optional)
  • Wetting And Drying

Bottom Drag
  • Manning
  • ks
  • ks (sediment coupled)

Horizontal Mixing
  • None
  • Constant
  • Smagorinsky
  • Wu
  • Elder
  • Warmup

Wind Stress (optional)
  • Wu
  • Constant
  • Kondo

Computational Mesh
  • Unstructured
  • Structured

Bathymetry
  • Static (potentially multiple)
  • Time Varying (potentially multiple)

Materials
  • Spatially Constant
  • Spatially Varying (potentially multiple)

Initial Conditions (optional)
  • Spatially Constant
  • Spatially Varying (potentially multiple)
  • Ocean Circulation Model
  • Restart File

Boundary Conditions
  • Water Level (potentially multiple)
  • Inflow/Outflow (potentially multiple)
  • Stage Discharge (potentially multiple)
  • Ocean Circulation Model (potentially multiple)
  • Atmospheric (potentially multiple)
  • Spectral Wave (potentially multiple)
  • Mass (potentially multiple)
  • Force (potentially multiple)
  • Zero Gradient and Reflective (potentially multiple)
  • Transport File

Hydraulic Structures
  • Weir (potentially multiple)
  • Culvert (potentially multiple)
  • Bridge (potentially multiple)
  • Porous (potentially multiple)
  • User-Defined Matrix (potentially multiple)
  • User-Defined Timeseries (potentially multiple)
  • Wall (potentially multiple)
  • Bubble Plume (potentially multiple)
  • Operational Control (optional, potentially multiple)

Model Output
  • Log Files And Diagnostics
  • Check Files (potentially multiple)
  • Point (potentially multiple)
  • Line (potentially multiple)
  • Mesh (potentially multiple)
  • Hydraulic Structure (potentially multiple)
  • Mass Balance
  • Restart File
  • Transport File

Vertical Mixing
  • None
  • Constant
  • Parametric
  • K-Epsilon
  • K-Omega

Salinity (optional)
  • None
  • Barotropic
  • Baroclinic

Temperature (optional)
  • None
  • Barotropic
  • Baroclinic

Tracer (optional)
  • None
  • Conservative
  • Decay
  • Settling

Atmospheric Heat Exchange (optional)
  • On
  • Off

Sediment
  • None
  • Barotropic
  • Baroclinic

Sediment Configuration
  • Sediment Control File

Water Quality
  • None
  • TUFLOW

Water Quality Configuration
  • Water Quality Control File

Particle Tracking Configuration
  • None
  • Particle Tracking Control File