20 Interesting Features of Innovyze H2OMap Sewer

Twenty interesting facts about H2OMap Sewer and an inverse color Map of the H2OMap Sewer Interface (Figure 1).  H2OMAP Sewer Sewer is a stand-alone GIS based program for use in the planning, design, analysis, and expansion of sanitary, storm and combined sewer collection systems. It is very good program if you like steady state analysis with peaking factors for manhole loading.

GIS Gateway, Import and Export of CSV and Shapefiles	Run Manager
Sewer Map based on MapInfo	Steady State Simulation
Bird’s Eye View	Design Simulation
Contouring and Annotation, Map Display of Input and Output Variables	EPS Simulation
Ten or More Unpeakable or Peakable Loads per Manhole	Input Data in the Attribute Browser
Point and Peaking Factor Loads for Steady State	Output Parameters in the Attribute Browser
Two Pass Solution with Adjusted Depth and Adjusted Velocity on the 2nd  Pass	Advanced Force Main Iterative Solution for complex Hazen Williams Force Main  Modeling, Optional Stormwater and RTK modeling
DB Tables with DB Queries	Modified Muskingum – Cunge  Numerical  Solution
Scenario, Facility Manager, Batch Simulations	Control over the number of link segments and Flow Attenuation
Data Inference, Network Tracing Tools	Output Graphics, Complete Mass Balance Report and Output Gravity Main,   Force Main and  Manhole Reports

Figure 1.  Inverse color Map of the H2OMap Sewer Interface

Advanced Force Main Solution and Gravity Main Attenuation in InfoSewer for better Pump, Force Main, Gravity Main Simulations

This blog is about using the Advanced Force Main Solution and Gravity Main Attenuation in InfoSewer for better Pump, Force Main, Gravity Main Simulations  

1. Select Advanced Force Main Solution and Flow Attenuation the Run Manager
2. The overall Continuity Error will be Better
3. Gravity mains will be closer to the Force Main Flows
4. Force Main Flows will be closer to the Pump flows 

5. Select Advanced Force Main Solution and Flow Attenuation the Run Manager	Force Main Flows will be closer to the Pump flows
   The overall Continuity Error will be Better	Gravity mains will be closer to the Force Main Flows

Advanced Force Main Solution and Gravity Main Attenuation in InfoSewer for better Pump, Force Main, Gravity Main Simulations

Reasons to use the Advanced Force Main Network Support Option in InfoSewer and H20Map Sewer

See the image for the two main reasons but another reason is that you get a better continuity error with this new(er) feature or option in InfoSewer

A Simple Advanced Model in InfoSewer

Rules for Force Mains in InfoSewer and H2OMap Sewer

The image at the bottom shows the rules for Force Mains in InfoSewer and H2OMap Sewer:

1.      Gravity Main
2.     Wet Well
3.     Pump
4.     Chamber Manhole
5.     Force Main  if you have many force mains the node BETWEEN two force mains has to be a Chamber Manhole

a.     The error messages for this are now rigorously enforced and they may not  have been in past versions

6.     Loading Manhole
7.     Gravity Main

Hazen Williams and Force Mains in SWMM 5

A few tips for using Hazen Williams and Force Mains in SWMM 5.   A key fact is to remember ONLY one flow in the middle of the link is computed in SWMM 5 so you may have to add Break nodes, use a smaller time step and use a flap gate depending on how often your pumps turn on.  If you do not have numerical problems with the time step you should get exactly the same head loss as you do in steady state Hazen Williams calculators when you use InfoSWMM, H2OMap SWMM and SWMM 5.

Figure 1.  Larger Tip Image 

Figure 2.  SWMM 5 compares well to the Hazen Williams Head loss calculators

The Equivalent n for Hazen-Williams in a Force Main of SWMM 5

The Equivalent n for Hazen-Williams in a Force Main of SWMM 5

SWMM 5 uses an equivalent Manning's n for the Hazen-Williams Coefficient for partial flow in a force main of SWMM 5.  The equivalent n is a function of the force main diameter, slope and the power equation used by Lew Rossman of the EPA in the SWMM 5 C code in the routine forcemain_getEquivN.   I am also including the C code to print out the HW value, diameter, slope and Equivalent n in the output file.  It is easy to add new of code to SWMM 5 for your thesis as long as you have a compiler (I suggest the current free Visual Studio from Microsoft) and know how to add the fprintf statements.  This simple addition gives you the power to understand more fully the inner working of SWMM 5 and add more content and understanding to your thesis or paper.

What are the Types of Force Mains (FM) in SWMM 5?

Subject:   What are the Types of Force Mains (FM) in SWMM 5?

There are five ways to model a force main in SWMM 5 for the combination of full and partial flow in the force main (Figure 1):

1.       Full Flow using Darcy-Weisbach for the friction loss

2.      Full Flow using Hazen-Williams for the friction loss

3.      Full Flow using Manning's n for the friction loss

4.      Partial Flow uses Manning's n for the friction loss for Force Main Equation options

If you use Darcy-Weisbach or Hazen-Williams then an equivalent Manning's n for a force main that results in the same normal flow value for a force main flowing full under fully turbulent conditions is calculated internally in SWMM 5 in forcemain.c

·         Equivalent n for H-W is 1.067 / Hazen-Williams Coefficient  * (Full Depth / Bed Slope) ^ 0.04 

·         Equivalent n for D-W is (Darcy-Weisbach friction factor/185) * (Full Depth) ^ 1/6 

Figure 1.  Types of Full and Partially Full Force Mains in SWMM 5

Smoother Switching Between Pumps in SWMM 5 - A better simulation of a VSP?

Subject - Smoother Switching Between Pumps in SWMM 5 - A better simulation of a VSP?

An oft requested feature in SWMM 5 is the ability to better simulate a variable speed pump.   The basic feature we are trying to model is multiple pumps between two nodes, one pump curve for all of the pumps and the ability to turn on and turn off the pumps based on either the head or depth at a Wet Well (Figure 1).  You can turn on or off the pumps Pump1, Pump2 and Pump3 based on the depth at the Wet Well but this feature is stepwise linear and usually uses three pump curves.  A better way to simulate this feature is to use the SWMM 5 Real Time Rules (RTC) to simulate the Pump setting based on a control curve.  

The Pump flow at any time step is the Pump Flow estimated from the Pump Curve (Figure 2) * The Pump Setting (Figure 3)

Each of the three pumps has a different Control Curve (Figure's 4, 5 and 6, respectively) which turns on or turns off the Pump based on a range of Wet Well Depths.  The overall effect is that the total flow summing all three pumps together is smoother (Figure 7 and Figure 8) and the user can simulate different pump speeds based on the same pump curve depending on which pump is currently on.

Figure 1.   Example RTC Rules and VSP Pumps in a SWMM 5 model.

Figure 2.  The Pump Curve Used for all 3 Pumps

  

Figure 3.  The Pump Setting for all Three Pumps

Figure 4.   Pump Control Curve for Pump 1.  The Pump has a Setting of ¼ between 0.5 and 3 feet at the node Wet Well and zero otherwise.

Figure 5.   Pump Control Curve for Pump 2.  The Pump has a Setting of 1/2 between 3 and 5 feet at the node Wet Well and zero otherwise.

Figure 6.   Pump Control Curve for Pump 3.  The Pump has a Setting of 1 above 5 feet at the node Wet Well and zero otherwise.

Figure 7.  The Flow in all 3 Pumps.

  

Figure 8.  The total flow from all three Pumps to the downstream node.

InfoSewer to InfoSWMM Import Tips

Subject:   InfoSewer to InfoSWMM Import Tips

InfoSewer to InfoSWMM Import Tips by dickinsonre Subject:   InfoSewer to InfoSWMM Import Tips The direct import of InfoSewer to InfoSWMM (Figure 1) is both direct and robust but you need to be aware of Run Manager changes to optimize the InfoSWMMmodel: 1.       Make sure that the Flow Units in InfoSWMM Run Manager match the default flow units in InfoSewer so that the DWF values are comparable, 2.      Make sure that the Output Flow Units in InfoSWMM match the Output Flow Units in InfoSewer so direct comparisons are easier, 3.      Add a Pump On and Pump Off depth to the Pumps in  InfoSWMM so that the pumps work better in a fully dynamic solution, 4.      The Fixed Pump Curves of InfoSewer should be checked in the Pump Curve section of InfoSWMM to make sure they are comparable, 5.      The InfoSWMM conduit step lengthening option should be used to speed up the model if you have short links in InfoSewer, 6.      You can check the overall balance in the two modeling platforms by comparing the System Load Graph in InfoSewer to the Total Inflow Graph inInfoSWMM. Figure 1   Dialog for Importing InfoSewer to InfoSWMM via Blogger http://www.swmm5.net/2013/08/infosewer-to-infoswmm-import-tips.html

SWMM 5 Control Rules for Pumps

Subject:  SWMM 5 Control Rules for Pumps

If you want to define the setting for a pump between the Pump On and Pump Off depths then an IF statement based on the Pump flow will work better as in this example, which changes the setting for the pump between a depth of 18 and 20 meters.   The IF statement based on flow will ensure the rule only applies when the Pump Control depth is moving from the Pump On depth to the Pump Off depth and NOT between the Pump Off and Pump On depth.  Figure 1 shows how the Pump Flow is related to the Pump Setting.

RULE CONTROL_Rule2

IF PUMP PUMP1 FLOW > 0.000000

AND NODE WELL HEAD > 18.000000

AND NODE WELL HEAD < 20.000000

THEN PUMP PUMP1 SETTING = 0.700000

PRIORITY 2.000000

Figure 1   Pump Flow is related to the Pump Setting

Lambda Calculus and Link Variables in the InfoSWMM, H2OMAP SWMM and SWMM 5 Dynamic Wave Solution

Subject:  Lambda Calculus and Link Variables in the InfoSWMM, H2OMAP SWMM and SWMM 5 Dynamic Wave Solution

Successive under-relaxation for the SWMM 5 Dynamic Wave Solution by dickinsonre Subject:  Successive under-relaxation for 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 1st 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 1st 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 1stiteration NOT using the under-relaxation parameter omega. via Blogger http://www.swmm5.net/2013/08/successive-under-relaxation-for-swmm-5.html

St. Venant equation – this is the link attribute data used when the St. Venant Equation is used inSWMM 5, H2OMAP SWMM and InfoSWMM.  Simulated Parameters from the upstream, midpoint and downstream sections of the link are used.

Normal Flow Equation – this is the link attribute data used when the Normal Flow Equation is used in H2OMAP SWMM. Only simulated parameters from the upstream end of the link are used if the normal flow equation is used for the time step.  The normal flow equation is used if the flow is supercritical or the water surface slope is less than the bed slope of the link.

Non Linear Term in the Saint Venant Equation of SWMM 5

The flow equation has six components that have to be in balance at each time step:

1. The unsteady flow term or dQ/dt

2. The friction loss term (normally based on Manning's equation except for full force mains),

3. The bed slope term or dz/dx

4. The water surface slope term or dy/dx,

5. The non linear term or d(Q^2/A)/dx and

6. The entrance, exit and other loss terms.

All of these terms have to add up to zero at each time step. If the water surface slope becomes zero or negative then the only way the equation can be balanced is for the flow to decrease. If the spike is due to a change in the downstream head versus the upstream head then typically you will a dip in the flow graph as the water surface slope term becomes flat or negative, followed by a rise in the flow as the upstream head increases versus the downstream head.

You get more than the normal flow based on the head difference because in addition to the head difference you also get a push from the non linear terms or dq3 and dq4 in this graph.