Storage Volume vs Depth Equation in SWMM 5

Subject:  Storage Volume vs Depth Equation in SWMM 5

A storage node in SWMM 5 can have either a functional form or a tabular depth/area table.  The area functional form of a storage node is:

Area           =      A * Depth^B + C  and the Volume has the form in  node.c of the SWMM 5 of

Volume     =      A/(B+1)*Depth^(1+B) + C*Depth

For example if C is 25 square meters, A is 20 and the exponent B is 0.5 we get the following values for area and volume and you can also plot a Scatter Plot of Volume vs Depth in SWMM 5 (Figure 1).

Depth	Area	Volume
Meters	M^2	M^3
0	25.00	0.00
1	45.00	38.33
2	78.28	87.71
3	109.64	144.28
4	140.00	206.67
5	169.72	274.07
6	198.99	345.96
7	227.92	421.94
8	256.57	501.70
9	285.00	585.00
10	313.25	671.64
11	341.33	761.44
12	369.28	854.26

Table 1.  Area and Volume for a Storage Node in SWMM 5.

Figure 1.  You can use a Scatter Graph in SWMM 5 to show the relationship between Volume and Depth.

Lambda Calculus in the SWMM 5 Dynamic Wave Solution

Subject:  Lambda Calculus in the SWMM 5 Dynamic Wave Solution

SWMM 5 uses the method of Successive under-relaxation to solve the Node Continuity Equation and the Link Momentum/Continuity Equation for a time step.  The dynamic wave solution in dynwave.c will use up to 8 iterations to reach convergence before moving onto the next time step.  The differences between the link flows and node depths are typically small (in a non pumping system) and normally converge within a few iterations unless you are using too large a time step.  The number of iterations is a minimum of two with the 1^st iteration NOT using the under-relaxation parameter omega. The solution method can be term successive approximation, fixed iteration or Picard Iteration, fixed-point combinatory, iterated function and Lambda Calculus. In computer science, iterated functions occur as a special case of recursive functions, which in turn anchor the study of such broad topics as lambda calculus, or narrower ones, such as the denotational semantics  of computer programs (http://en.wikipedia.org/wiki/Iterated_function). 

In the SWMM 5 application of this various named iteration process there are three main concepts for starting, iterating and stopping the iteration process during one time step:

·         The 1^st guess of the new node depth or link flow is the current link flow (Figure 3) and the new estimated node depths and link flows are used at each iteration to estimate the new time step depth or flow.  For example, in the node depth (H) equation dH/dt = dQ/A the value of dQ or the change in flow and the value of A or Area is updated at each iteration based on the last iteration’s value of all node depths and link flows.  

·         A bound or a bracket on each node depth or link flow iteration value is used by averaging the last iteration value with the new iteration value.  This places a boundary on how fast a node depth or link flow can change per iteration – it is always ½ of the change during the iteration (Figure 1).  

·         The Stopping Tolerance (Figure 2) determines how many iterations it takes to reach convergence and move out of the iteration process for this time step to the next time step.

Figure 1.  Under relaxation with an omega value of ½ is done on iterations 2 through a possible 8 in SWMM 5. This is not done for iteration 1.

Figure 2.  if the change in the Node Depth is less than the stopping tolerance in SWMM 5 the node is considered converged.  The stopping tolerance has a default value of 0.005 feet in SWMM 5.0.022. 

Figure 3.  The differences between the link flows and node depths are typically small (in a non pumping system) and normally converge within a few iterations unless you are using too large a time step.  The number of iterations is a minimum of two with the 1^st iteration NOT using the under-relaxation parameter omega.

InfoSWMM Selection Set and Domain Manager

Subject:  InfoSWMM Selection Set and Domain Manager

InfoSWMM and H2Map SWMM Selection Set and Domain Manager by dickinsonre Subject:   InfoSWMM and H2Map SWMM Selection Set and Domain Manager You can use the Domain to easily make selection sets using these two steps.  You make a Domain which is the areas of the network you are interested in at the current time and then save your Domain of Interest in a Selection Set. Step 1:  Go to Domain Manager and use Map Selection, Query or the Network to make a domain Step 2.  Go to Selection Sets in the Operation Tab of the  Attribute Browser and make a New Set and load the domain into your set. via Blogger http://www.swmm5.net/2013/08/infoswmm-and-h2map-swmm-selection-set.html

InfoSWMM and H2OMAP SWMM Import and Export of HEC-RAS Geometry Data

Subject: InfoSWMM and H2OMAP SWMM Import and Export of HEC-RAS Geometry Data

InfoSWMM and H2OMAP SWMM Import and Export of HEC-RAS Geometry Data by dickinsonre InfoSWMM v11 and H2OMAP SWMM v10 have new import and export features for HEC-RAS interaction.   The echange commands are in the exchange menu (Table 1) and you can import HEC-RAS geometry files (Figure 1), edit imported Transect Data (Figure 2 and 3) and export thedata back to a HEC-RAS geometry file (Figure 4 and 5 and Table 2). Exchange Import Manager Exchange Export Manager Exchange ODBC Exchange Exchange Import Generate File Exchange Import… Exchange (Conveyance Nodes) Exchange Conveyance (Links) Exchange (Disable Auto-Length Calculation) Exchange Export… Exchange Export Generate File Exchange (Conveyance Nodes) Exchange Conveyance (Links) Exchange (Disable Auto-Length Calculation) Exchange Convert Polyline Exchange Import EPA SWMM 5 Exchange Export EPA SWMM 5 Exchange Import HEC-RAS Data Exchange Export HEC-RAS Data Exchange Export Hotstart File Exchange Append Nodes Exchange GIS Gateway Table 1.  Exchange commands in InfoSWMM and/or H2OMAP SWMM Figure 1.   Import HEC-RAS command imports Geometry Files which will have the extension go1, go2 etc. Figure 2.   The imported Transects can be viewed and edited in the Operations Tab  of the InfoSWMM Browser. Figure 3.   The imported Transects can be used as a SWMM 5 Irregular Channel Transect. Figure 4.   Export HEC-RAS command exports a geometry file containing the active Transects in InfoSWMM. Figure 5.   Export HEC-RAS allows you to choose a directory and a name for the exported geometry file. GEOM Title= MWHS-SWMM Export to HEC-RAS River Reach= CHO Type RM Length L Ch R = 1 ,5.065 ,471.716902,515.260000,471.716902 BEGIN DESCRIPTION: River Mile 5.065 END DESCRIPTION: #Sta/Elev= 68        0   214.4      11   213.9      39   212.3      41   211.8     141   209.6      174   208.0     275   205.1     293   203.9     297   201.6     299   201.3      307   199.9     313   200.8     316   202.1     329   203.4     329   205.4      366   208.6     413   208.5     417   208.3     429   206.2     434   205.8      441   203.4     447   206.3     449   206.4     488   208.1     502   208.1      506   208.1     550   207.0     559   206.1     566   205.9     566   205.9      575   205.8     585   206.7     587   206.6     624   205.9     638   206.0      644   205.9     651   205.8     667   206.8     681   207.3     696   207.7      723   207.8     724   207.8     739   207.5     763   208.1     787   209.1      816   209.3     920   210.0     970   209.8     998   209.8    1055   209.8     1076   209.5    1079   209.6    1097   209.9    1108   210.1    1130   210.4     1225   210.6    1358   211.1    1372   211.1    1419   211.3    1426   210.6     1443   211.4    1472   211.5    1647   211.5    1670   211.5    1745   211.7     1796   212.2    1868   213.4    1888   214.2 #Mann= 3 , 1 , 0        0     0.1       0     275    0.04       0     366    0.08       0 Bank Sta=274.500000,365.500000                                 Table 2.   The exported HEC-RAS Geometry File from InfoSWMM via Blogger http://www.swmm5.net/2013/08/infoswmm-and-h2omap-swmm-import-and.html

H2OMAP Sewer and InfoSewer Water Quality Options

Subject:   H2OMAP Sewer and InfoSewer Water Quality Options

H2OMAP Sewer and InfoSewer Water Quality Options by dickinsonre Subject:   H2OMAP Sewer and InfoSewer Water Quality Options  You can model 8 options in H2OMAP Sewer and InfoSewer to simulate various aspects of Water Quality (Figure 1).  If you make the base scenario no water quality you can have the same network, same loading but different aspects of water quality in seven child scenario's (Figure 2).  The parameters for each water quality option is shown in the Quality Tab of the SimulationOptions Dialog. Figure 1.  Water Quality Simulation Choices in H2OMAP Sewer and InfoSewer.  Figure 2.  Water Quality Simulation Choices in the Scenario Explorer of H2OMAP Sewer and InfoSewer via Blogger http://www.swmm5.net/2013/08/h2omap-sewer-and-infosewer-water.html

The SWMM 5, 1D Components in InfoSWMM 2D

Note:  The SWMM 5 1D Components in InfoSWMM 2D

The SWMM 5 1D Components in InfoSWMM 2D by dickinsonre Note:  The SWMM 5 1D Components in InfoSWMM 2D InfoSWMM 2D uses standard SWMM 5 components to connect the 1D Nodes to the 2D Mesh.  A bottom outlet orifice at the maximum depth of the node drains to a SWMM 5 Outfall at the fixed elevation equal to the Node Rim Elevation. Flow can go into or out of the Outfall from the 1D element from or to the 2D Mesh. InfoSWMM 2D automatically makes the necessary elements if 2D is used and the new elements are listed in the Hydqua.inp file, which is very similar to the Tab Delimited SWMM5 Input file.  The HYDQUA.inp is very similar to the Excel Tab formatted file of SWMM 5 with a few additional sections and added features: 1st Difference:   The Flood Node Data Section tell the 2D engine which Node has a 1D-2D connection and which 2D mesh element the 1D Node drains to when it is flooded. [Flood_Node] 10309D      848 80408        131 2nd Difference:  Outfall Nodes are created for the 2D Mesh Element connected to the 1D Node, the outfalls are Fixed Outfalls and the fixed head is the Node Rim Elevation of the 1D node listed in the Flooded Node Section [OUTFALLS] 10208  89.900000     FREE  NO 10208A           89.900000     FIXED            94.400000     YES 10208B           89.900000     FREE  NO 10208C           89.900000     FREE  NO 10208D           89.900000     FREE  NO 10208E           89.900000     FREE  NO 10309D_OUTFALL           101.600000            FIXED           111.000000            NO 80408_OUTFALL             120.000000            FIXED           133.400000            NO 3rd  Difference:  Bottom Outlet Orifices are created to connect the 1D node to the 2D Mesh Element Outfall with the Flood Discharge Coefficient entered by the user and a crest height equal to the maximum depth of the node [ORIFICES] OR1@82309B-15009B  82309B      15009B      BOTTOM    0.000000   0.850000   NO OR1@82309D-82308D  82309D      82308D      SIDE 0.000000   0.850000   NO 10309D_ORIFICE       10309D      10309D_OUTFALL       BOTTOM    9.400000   0.030000   NO 80408_ORIFICE          80408        80408_OUTFALL         BOTTOM    13.400000 0.030000   NO