1D Pumps

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Introduction

This post provides a modelling example for a 1D pump using a fixed flow rate and pump curve. For this example we will model a pump in two common situations (2D-2D & 1D-2D).

Pump Attributes

A pump needs to first be digitised in a 1d_nwke layer. The direction of the polyline must go from inlet to outlet as a pump is unidirectional (? Is that true). The attributes required for a pump in your 1d_nwke layer can be found within the 2015 TUFLOW manual.
In the 1d_nwk layer, the following attributes are required:

1. ID = ID of the channel
   
2. Type = "P"
   
3. Len_or_ANA = Nominal length in m (only used for calculating nodal storage if UCS is on)
   
4. US_Invert = Upstream invert level of the channel
   
5. DS_Invert = Downstream invert level of the channel
   
6. Inlet_Type = Used to specify the pump curve in the Depth Discharge database.
   

2D-2D Configuration

Because pumps are zero length channels they do not create automatic nodes at the upstream and downstream end. If you ran the model with just a pump polyline you will get ERROR 1353 - No NA data for Node. To remove this error you will need to digitise a node within a separate 1d nwke layer and give a nominal storage amount in the “Len_or_NA” attribute for the 1d nwke ‘Node’, see the example below.
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To connect the pump to the 2d domain you will also need to digitise an SX connection. In the figure below I have showed both the 1d node and 2d SX points as being separate from each other for illustrative purposes only – they should both be snapped to the end of the pump polyline. SX connections are required at connections to 2D domains to transfer water from the 1D node to the 2D. Without the SX connection, water will build up within the node and cause an instability.
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1D-2D Configuration

Connecting a pump from a 1d network to the 2d domain or vice versa is similar to the configuration above, the only difference is that the connection with a 1d structure does not require a 2d SX connection or 1d nwke ‘Node’. A storage chamber in the 1d network can also be modelled using a 1d_na node with an elevation vs area .csv assigned to the node.
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Estry Control File Setup

Within the *.ecf the following commands and files are at a minimum required to run a pump with no logically control:

Read GIS Network ==..\model\mi\1d_nwke_xxxxx.MIF
Depth Discharge Database ==..\bc_dbase\xxxxx.csv

If you do not specify a Depth-Discharge database then you will be faced with ERROR 1118 – Could not find a y-Q curve.

The table below contains a complete list of the 2D check files. Note that for linked 2D/1D or 2D/2D models these check files are outlined in the sections below.

Filename prefix / suffix	Brief Description
_2d_bc_tables_check.csv	Tabular data as read from the boundary condition database via any 2d_bc layers and after any adjustments (eg. time shift). Provides traceability to original data source. Note: the boundary values do not include the effects of any 2d_bc attributes such as f.
_bcc_check.mif _bcc_check_R.shp	GIS files providing trace back information and uses cells, rather than point/line objects to show 2D BCs.
_DEM_M.flt _DEM_M.asc	A DEM of the final material ID values, similar to the DEM_Z check grid described below. The .tcf command Grid Format can be used output this check file in ASCII format rather than the default FLT format.
_DEM_Z.flt _DEM_Z.asc	A DEM of the final ground/bathymetry elevations, including those from any 1D WLL mesh. The file is given a DEM_Z extension, and can be readily opened by most GIS and other GUIs. The default size of the grid cells is half the smallest 2D cell size. This can be changed using the Grid Output Cell Size == command. To exclude writing this file, include “DEM_Z” in the Write Check Files EXCLUDE list. The Grid Format == command can be used to control the format of the file. The DEM_M and DEM_Z check grids are written if the model start up is forced to only process the .tgc file. To do this, don’t specify or comment out, the BC Control File command.
_dom_check.mif _dom_check_R.shp	Contains a rectangle for each 2D domain showing the location, orientation and size of the domain. Within this domain, cells can be turned on or off, outside this domain no 2D calculations can be performed.
_fc_check.mif _fc_check_R.shp	GIS layer of the final arrangement of flow constrictions (FC). The flow constrictions are written as individual square cells of the same shape as the grid cells, even if the FC was specified using points or lines/polylines.
_fcsh_uvpt_check.mif _fcsh_uvpt_check_P.shp	Contains information on adjustments to the ZU/ZV cell sides as modified by Read GIS FC Shape == commands.
_glo_check.mif _glo_check_P.shp	GIS layer of any gauge level output (GLO) locations.
_grd_check.mif _grd_check_R.shp	GIS layer of the final 2D grid. Represents the final grid including modifications from the .tgc file, boundary specifications and flow constrictions. Note that the Material and bed resistance (eg. Mannings_n) attributes do not include any modifications due to flow constrictions as these are applied directly to the cell mid-sides (rather than the cell centre). To view these use the _uvpt_check.mif/.shp file. Can also be written at different stages within a .tgc file (see Write GIS Grid == command). The file contains all modifications to the 2D grid at the point in the .tgc file that it is written. Note that a number of additional attributes are appended to the_grd_check layer when some features of TUFLOW have been used.
_input_layers.mif	GIS layer contain full filepaths to all input layers used to compile the model.
_lfcsh_uvpt_check.mif _lfcsh_uvpt_check_P.shp	Contains information on adjustments to the ZU/ZV cell sides as modified by Read GIS Layered FC Shape == commands.
_lp_check.mif _lp_check_L.shp	GIS layer of any 2D longitudinal profile(s).
_po_check.mif _PO_check_P.shp _PO_check_L.shp	GIS layer of any 2D plot output location(s). The layer shows points and lines occurring from the cell centres, rather than their exact locations in the original file(s). For the shapefile the points and lines are output in separate files, see also FAQ Shapefiles.
_sac_check.mif _sac_check_R.shp	GIS layer of the lowest cell selected for Read GIS SA inputs, and cells selected if using Read GIS SA PITS .
_sh_obj_check.mif _sh_obj_check_R.shp	Contains objects such as buffer polygons used for wide lines, triangles generated for TINs within polygons, and regions and polylines for thick and thin lines to illustrate areas that have been modified by Create TIN Zpts (if the WRITE TIN option is specified), Read GIS Z Shape, Read GIS Variable Z Shape, Read GIS FC Shape and Read GIS Layered FC Shape commands.
_uvpt_check.mif _uvpt_check_P.shp	GIS layer containing the initial velocities, roughness value, FLC, WrF, FC lid depth and FC BD factor at the U and V points. For materials that vary Manning’s n with depth, the Manning_n attribute contains the Manning’s n value at the higher depth.
_vzsh_check.mif _vzsh_check_P.shp _vzsh_check_L.shp	Contains information on Zpts that have been modified by Read GIS Variable Z Shape == commands.
_zln_zpt_check.mif _zln_zpt_check_P.shp	GIS layer containing Zpts that have been modified by Read GIS Z Line == commands, the type of Z Line and the Z Line filename. This feature is very useful for checking which Zpts that the Z Lines have modified. Note: It does not include any GULLY lines. When written in .mif/.mid format, the points are given different symbology according to whether they have been raised or lowered (up or down triangles) or remain unchanged (a cross).
_zpt_check.mif _zpt_check_P.shp	GIS layer of the final 2D Zpts. Represents the final Zpts including all modifications from the .tgc file, and any flow constrictions in the .tcf file. Can also be written at different stages within a .tgc file (see the Write GIS Zpts command). The file contains all modifications to the 2D Zpts at the point in the .tgc file that it is written. This allows checking of the elevations at different stages of building the topography.
_zsh_zpt_check.mif _zsh_zpt_check_P.shp	Contains Zpts that have been modified by Read GIS Z Shape commands. When written in .mif/.mid format, the points are given different symbology according to whether they have been raised or lowered (up or down triangles) or remain unchanged (a cross).

Depth Discharge Database

Constant Flow Rate

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Pump Curve

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Creating a TUFLOW pump curve

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Any further questions please email TUFLOW support: support@tuflow.com