Four Key Parameters to Control Your Model, Time Step, Iterations, Time Step Lengthening and Hot Start File

Comments

Post a Comment

Popular posts from this blog

Vacuum Sewers

Image
Vacuum Sewers Compiled by: Beat Stauffer (seecon international gmbh) Source:   http://www.sswm.info/category/implementation-tools/wastewater-collection/hardware/sewers/vacuum-sewers Executive Summary Vacuum sewerage systems consist of a vacuum station, where the vacuum is generated, the vacuum pipeline system, collection chambers with collection tanks and interface valve units. In contrast to conventional gravity sewerage systems with intermediate pumping stations, the permanent pressure within the vacuum system is maintained below atmospheric pressure. Moreover, vacuum technology reduces water consumption considerably, enabling flexible installations regardless of topography and water availability. In addition, it allows for the use of alternative wastewater handling (blackwater and greywater separation). In Out Blackwater ,  Faecal Sludge ,  Greywater , Brownwater ,  Urine  or  Yellowwater ,  Faeces , Excreta ,  Energy Blackwater ,  Non-bi...
Read more

More St Venant Equations in #SWMM5

Image
This blog shows the relationship between the terms dq1, dq2, dq3 and dq4 in the SWMM5 code and the St. Venant Partial Differential Equations. dq2 = Time Step * Area wtd * (Head Downstream – Head Upstream) / Link Length or dq2 = Time Step * Area wtd * (HGL) / Link Length Qnew = (Qold – dq2 + dq3 + dq4) / ( 1 + dq1) when the force main is full dq3 and dq4 are zero and Qnew = (Qold – dq2) / ( 1 + dq1) The dq4 term in dynamic.c uses the area upstream (a1) and area downstream (a2), the midpoint velocity, the sigma factor (a function of the link Froude number), the link length and the time step or dq4 = Time Step * Velocity * Velocity * (a2 – a1) / Link Length * Sigma the dq3 term in dynamic.c uses the current midpoint area (a function of the midpoint depth), the sigma factor and the midpoint velocity dq3 = 2 * Velocity * ( Amid(current iteration) – Amid (last time step) * Sigma dq1 = Time Step * RoughFactor / Rwtd^1.333 * |Velocity| The weighted area (Awtd) is used in the dq2 term of the St...
Read more

How to Import Link Shapefiles into InfoSWMM

Image
How to Import Link Shapefiles into InfoSWMM This blog describes how to use the GIS Gateway tool in InfoSWMM to import shapefiles and make InfoSWMM DB Tables and Arc Map Layers from the Shapefiles.   The import of shapefiles into either InfoSWMM or H2oMap SWMM is very flexible and uses the Command Exchange/GIS Gateway.  If you are starting from a new Arc Map then it is best to first add the shapefiles to Arc Map, initialize the Map to the Coordinate System of the Shapefiles and then import the Shapefiles using GIS Gateway to make an InfoSWMM Junction Layer.  The Steps to use the GIS Gateway for Nodes Step 1.    Add the Pipe or Link Shapefiles and Initialize the Arc Map to the Coordinate System of the Shapfile using either the Personal or File GeoDatabase Options. Step 2.    Use the GIS Gateway command and set up the Shapefile to load into the Conduit Tables of InfoSWMM with the proper GIS Mapping Field. Step 3.    You need to Map ...
Read more