TUFLOW 1D Channels and Hydraulic Structures - Revision history

Emilie Nielsen: /* What entry/exit loss and contraction coefficients should I use for 1D culverts? */

2026-03-02T02:45:56Z

What entry/exit loss and contraction coefficients should I use for 1D culverts?

← Older revision		Revision as of 12:45, 2 March 2026
Line 78:		Line 78:

	== What entry/exit loss and contraction coefficients should I use for 1D culverts? ==		== What entry/exit loss and contraction coefficients should I use for 1D culverts? ==
	We don’t provide hard recommendations on the exit and entry losses to use for culverts as we have found different organisations around the world, typically government, have their own guidelines for different types of inlets configurations and require these to be used, for example, the <u>[https://www.ipwea-qnt.com/Web/Web/Resources/Queensland-Urban-Drainag-Manual-QUDM.aspx QLD Urban Drainage Manual ~~\| IPWEA-QNT~~]</u> (QUDM). However, it is very important to understand how losses are applied and that different 1D solvers may treat them differently. For cross-checking your results from any hydraulic modelling software, a simple calculation applying the entry and exit losses (allowing for any automatic adjustments as discussed below) to the computed head (V2/2g), plus allowing any surface roughness losses (Manning's equation) for longer culverts, is the best practice for culverts flowing in a sub-critical flow condition (i.e. downstream controlled flow).<br>		We don’t provide hard recommendations on the exit and entry losses to use for culverts as we have found different organisations around the world, typically government, have their own guidelines for different types of inlets configurations and require these to be used, for example, the <u>[https://www.ipwea-qnt.com/Web/Web/Resources/Queensland-Urban-Drainag-Manual-QUDM.aspx QLD Urban Drainage Manual]</u> (QUDM). However, it is very important to understand how losses are applied and that different 1D solvers may treat them differently. For cross-checking your results from any hydraulic modelling software, a simple calculation applying the entry and exit losses (allowing for any automatic adjustments as discussed below) to the computed head (V2/2g), plus allowing any surface roughness losses (Manning's equation) for longer culverts, is the best practice for culverts flowing in a sub-critical flow condition (i.e. downstream controlled flow).<br>

	For the entrance loss values, the approach should be to use values as quoted in the literature or guidelines for the inlet shape and design unless there is evidence to use another value (e.g. comparison with reliable calibration data would indicate different energy losses).		For the entrance loss values, the approach should be to use values as quoted in the literature or guidelines for the inlet shape and design unless there is evidence to use another value (e.g. comparison with reliable calibration data would indicate different energy losses).

Emilie Nielsen: /* Structures */

2026-03-02T02:30:05Z

Structures

← Older revision		Revision as of 12:30, 2 March 2026
Line 21:		Line 21:
	\| [[1D_Culverts \| Culverts]]\|\| 1D-2D connections, flow regimes, operational control and common check files used.		\| [[1D_Culverts \| Culverts]]\|\| 1D-2D connections, flow regimes, operational control and common check files used.
	\|-		\|-
	\| [[1D_Bridges \| Bridges]]\|\| Loss theory, irregular shaped bridges and common check files used~~. Includes links to tutorial and example models where bridges are represented in 2D~~.		\| [[1D_Bridges \| Bridges]]\|\| Loss theory, irregular shaped bridges and common check files used.
	\|-		\|-
	\| [[1D_Weirs \| Weirs]]\|\| Weir types		\| [[1D_Weirs \| Weirs]]\|\| Weir types

Anne.Kolega: /* How can trash screens be represented? */

2026-02-25T07:12:36Z

How can trash screens be represented?

← Older revision		Revision as of 17:12, 25 February 2026
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	A trash screen is a physical barrier, typically made from bars or mesh, placed at the inlet or outlet of a culvert, pipe, or channel to prevent debris from entering or exiting the structure.		A trash screen is a physical barrier, typically made from bars or mesh, placed at the inlet or outlet of a culvert, pipe, or channel to prevent debris from entering or exiting the structure.

	Trash screens can be represented by applying additional head losses and blockage effects in accordance with <u>[https://www.ipwea-qnt.com/~~products-resources~~/~~qudm~~/ QUDM]</u> guidance. The approach depends on the location of the screen and the degree of blockage.		Trash screens can be represented by applying additional head losses and blockage effects in accordance with <u>[https://www.ipwea-qnt.com/Web/Web/Resources/Queensland-Urban-Drainag-Manual-QUDM.aspx QUDM]</u> guidance. The approach depends on the location of the screen and the degree of blockage.

	Possible use cases include:		Possible use cases include:

Anne.Kolega: /* What entry/exit loss and contraction coefficients should I use for 1D culverts? */

2026-02-24T04:55:30Z

What entry/exit loss and contraction coefficients should I use for 1D culverts?

← Older revision		Revision as of 14:55, 24 February 2026
Line 78:		Line 78:

	== What entry/exit loss and contraction coefficients should I use for 1D culverts? ==		== What entry/exit loss and contraction coefficients should I use for 1D culverts? ==
	We don’t provide hard recommendations on the exit and entry losses to use for culverts as we have found different organisations around the world, typically government, have their own guidelines for different types of inlets configurations and require these to be used, for example, the <u>[https://www.ipwea-qnt.com/~~products-resources~~/~~qudm~~/ QLD Urban Drainage Manual \| IPWEA-QNT]</u> (QUDM). However, it is very important to understand how losses are applied and that different 1D solvers may treat them differently. For cross-checking your results from any hydraulic modelling software, a simple calculation applying the entry and exit losses (allowing for any automatic adjustments as discussed below) to the computed head (V2/2g), plus allowing any surface roughness losses (Manning's equation) for longer culverts, is the best practice for culverts flowing in a sub-critical flow condition (i.e. downstream controlled flow).<br>		We don’t provide hard recommendations on the exit and entry losses to use for culverts as we have found different organisations around the world, typically government, have their own guidelines for different types of inlets configurations and require these to be used, for example, the <u>[https://www.ipwea-qnt.com/Web/Web/Resources/Queensland-Urban-Drainag-Manual-QUDM.aspx QLD Urban Drainage Manual \| IPWEA-QNT]</u> (QUDM). However, it is very important to understand how losses are applied and that different 1D solvers may treat them differently. For cross-checking your results from any hydraulic modelling software, a simple calculation applying the entry and exit losses (allowing for any automatic adjustments as discussed below) to the computed head (V2/2g), plus allowing any surface roughness losses (Manning's equation) for longer culverts, is the best practice for culverts flowing in a sub-critical flow condition (i.e. downstream controlled flow).<br>

	For the entrance loss values, the approach should be to use values as quoted in the literature or guidelines for the inlet shape and design unless there is evidence to use another value (e.g. comparison with reliable calibration data would indicate different energy losses).		For the entrance loss values, the approach should be to use values as quoted in the literature or guidelines for the inlet shape and design unless there is evidence to use another value (e.g. comparison with reliable calibration data would indicate different energy losses).

Anne.Kolega: /* What entry/exit loss and contraction coefficients should I use for 1D culverts? */ updated link to latest QUDM

2026-02-24T04:35:30Z

What entry/exit loss and contraction coefficients should I use for 1D culverts?: updated link to latest QUDM

← Older revision		Revision as of 14:35, 24 February 2026
Line 78:		Line 78:

	== What entry/exit loss and contraction coefficients should I use for 1D culverts? ==		== What entry/exit loss and contraction coefficients should I use for 1D culverts? ==
	We don’t provide hard recommendations on the exit and entry losses to use for culverts as we have found different organisations around the world, typically government, have their own guidelines for different types of inlets configurations and require these to be used, for example, the <u>[https://www.ipwea-qnt.com/products-resources/qudm/ ~~Queensland~~ Urban Drainage Manual]</u> (QUDM). However, it is very important to understand how losses are applied and that different 1D solvers may treat them differently. For cross-checking your results from any hydraulic modelling software, a simple calculation applying the entry and exit losses (allowing for any automatic adjustments as discussed below) to the computed head (V2/2g), plus allowing any surface roughness losses (Manning's equation) for longer culverts, is the best practice for culverts flowing in a sub-critical flow condition (i.e. downstream controlled flow).<br>		We don’t provide hard recommendations on the exit and entry losses to use for culverts as we have found different organisations around the world, typically government, have their own guidelines for different types of inlets configurations and require these to be used, for example, the <u>[https://www.ipwea-qnt.com/products-resources/qudm/ QLD Urban Drainage Manual \| IPWEA-QNT]</u> (QUDM). However, it is very important to understand how losses are applied and that different 1D solvers may treat them differently. For cross-checking your results from any hydraulic modelling software, a simple calculation applying the entry and exit losses (allowing for any automatic adjustments as discussed below) to the computed head (V2/2g), plus allowing any surface roughness losses (Manning's equation) for longer culverts, is the best practice for culverts flowing in a sub-critical flow condition (i.e. downstream controlled flow).<br>

	For the entrance loss values, the approach should be to use values as quoted in the literature or guidelines for the inlet shape and design unless there is evidence to use another value (e.g. comparison with reliable calibration data would indicate different energy losses).		For the entrance loss values, the approach should be to use values as quoted in the literature or guidelines for the inlet shape and design unless there is evidence to use another value (e.g. comparison with reliable calibration data would indicate different energy losses).

Anne.Kolega: /* Structures */

2026-02-24T03:54:01Z

Structures

← Older revision		Revision as of 13:54, 24 February 2026
Line 21:		Line 21:
	\| [[1D_Culverts \| Culverts]]\|\| 1D-2D connections, flow regimes, operational control and common check files used.		\| [[1D_Culverts \| Culverts]]\|\| 1D-2D connections, flow regimes, operational control and common check files used.
	\|-		\|-
	\| [[1D_Bridges \| Bridges]]\|\| Loss theory, irregular shaped bridges and common check files used.		\| [[1D_Bridges \| Bridges]]\|\| Loss theory, irregular shaped bridges and common check files used. Includes links to tutorial and example models where bridges are represented in 2D.
	\|-		\|-
	\| [[1D_Weirs \| Weirs]]\|\| Weir types		\| [[1D_Weirs \| Weirs]]\|\| Weir types

Abrar.Alttahir: /* How can a flow splitter with a nib wall be modelled? */

2026-01-21T01:26:59Z

How can a flow splitter with a nib wall be modelled?

← Older revision		Revision as of 11:26, 21 January 2026
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	-->		-->

			<!--
	== How can a flow splitter with a nib wall be modelled? ==		== How can a flow splitter with a nib wall be modelled? ==
	<span style="color:red; font-weight:bold;">UNDER CONSTRUCTION</span>

	A flow splitter with a nib wall can be modelled by introducing a 1D weir between the manhole and the relevant outlet pipe. The weir crest elevation should be set equal to the height of the nib wall within the chamber. This setup allows low flows to discharge through one pipe, while higher flows overtop the weir into a secondary outlet, replicating the behaviour of a physical flow splitter.		A flow splitter with a nib wall can be modelled by introducing a 1D weir between the manhole and the relevant outlet pipe. The weir crest elevation should be set equal to the height of the nib wall within the chamber. This setup allows low flows to discharge through one pipe, while higher flows overtop the weir into a secondary outlet, replicating the behaviour of a physical flow splitter.
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	Refer to the schematic example below for this configuration.		Refer to the schematic example below for this configuration.

	<ol>
	[[File:Manhole flow splitter topview.png~~\|alt=~~\|300x300px]]		[[File:Manhole flow splitter topview.png\|300x300px]]
	</ol>
	<br>		<br>
			-->

	{{Tips Navigation		{{Tips Navigation

Abrar.Alttahir: /* How can fishway baffles in a culvert be modelled? */

2026-01-21T01:26:03Z

How can fishway baffles in a culvert be modelled?

← Older revision		Revision as of 11:26, 21 January 2026
Line 247:		Line 247:
	</ol>		</ol>

			<!--
	== How can fishway baffles in a culvert be modelled? ==		== How can fishway baffles in a culvert be modelled? ==
	<span style="color:red; font-weight:bold;">UNDER CONSTRUCTION</span>

	Fishway baffles are barriers inside a culvert that slow the water and help fish swim through.		Fishway baffles are barriers inside a culvert that slow the water and help fish swim through.
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	For both options, sensitivity testing is recommended because at low flows the way the culvert is defined can change the results. These methods do not include turbulence or detailed 3D water movement around the baffles. If accurate fish passage flows are required, a CFD 3D model can be used to determine the flows and those flows can then be applied using a 1D Q type channel.		For both options, sensitivity testing is recommended because at low flows the way the culvert is defined can change the results. These methods do not include turbulence or detailed 3D water movement around the baffles. If accurate fish passage flows are required, a CFD 3D model can be used to determine the flows and those flows can then be applied using a 1D Q type channel.

	<ol>
	[[File:Rectangular culvert baffled.png~~\|alt=~~\|300x300px]]		[[File:Rectangular culvert baffled.png\|300x300px]]
			-->
	</ol>

	== How can a flow splitter with a nib wall be modelled? ==		== How can a flow splitter with a nib wall be modelled? ==

Abrar.Alttahir: /* How can a flow splitter with a nib wall be modelled? */

2025-11-13T02:16:17Z

How can a flow splitter with a nib wall be modelled?

← Older revision		Revision as of 12:16, 13 November 2025
Line 268:		Line 268:
	<span style="color:red; font-weight:bold;">UNDER CONSTRUCTION</span>		<span style="color:red; font-weight:bold;">UNDER CONSTRUCTION</span>

	A flow splitter with a nib wall can be modelled ~~in TUFLOW~~ by introducing a 1D weir between the manhole and the relevant outlet pipe. The weir crest elevation should be set equal to the height of the nib wall within the chamber. This setup allows low flows to discharge through one pipe, while higher flows overtop the weir into a secondary outlet, replicating the behaviour of a physical flow splitter.		A flow splitter with a nib wall can be modelled by introducing a 1D weir between the manhole and the relevant outlet pipe. The weir crest elevation should be set equal to the height of the nib wall within the chamber. This setup allows low flows to discharge through one pipe, while higher flows overtop the weir into a secondary outlet, replicating the behaviour of a physical flow splitter.

	The main outlet pipes are connected through a manhole, which automatically applies appropriate entry and exit losses. For outlets that do not connect further downstream, entry and exit losses should be manually defined in the attributes.		The main outlet pipes are connected through a manhole, which automatically applies appropriate entry and exit losses. For outlets that do not connect further downstream, entry and exit losses should be manually defined in the attributes.

	Refer to the schematic example below for this configuration.		Refer to the schematic example below for this configuration.
			<ol>

			[[File:Manhole flow splitter topview.png\|alt=\|300x300px]]
			</ol>
	<br>		<br>

Abrar.Alttahir: /* How can a flow splitter with a nib wall be modelled? */

2025-11-13T01:14:25Z

How can a flow splitter with a nib wall be modelled?

@@ Line 264: / Line 264: @@
 [[File:Rectangular culvert baffled.png|alt=|300x300px]]
 </ol>
 <br>