How to Use Two Control Curves in SWMM 5 to Simulate a Head Difference Rule

Subject:  How to Use Two Control Curves in SWMM 5 to Simulate a Head Difference Rule

How to Use Two Control Curves in SWMM 5 to Simulate a Head Difference Rule by dickinsonre Subject:  How to Use Two Control Curves in SWMM 5 to Simulate a Head Difference Rule  The SWMM 5 control rules for Real Time Control (RTC) do not allow the rule to be governed by the head across the orifice but does allow rules based on the depth, head and inflow at any node.  If you have an Orifice in which you want the Orifice to be open when the head difference across the Orifice is either less than or greater than zero then and closed when the head difference is close to zero then you can use two Orifices (Figure 1) and two rules (Figure 2) to control the orifice setting for Orifice1 and Orifice2.  In attached file the two rules have the settings set to two control curves.  Orifice1 will start open and close gradually as the depth at Node UPNode increases, Orifice2 will start closed and gradually open when depth in Node DNode increases.  Possible variations are to control Orifice1 based on the DNode and node UPNode to control Orifice2.  RULE Orifice1 IF  NODE UPNode  Depth >= 0 THEN ORIFICE ORIFICE1 SETTING = Curve RuleOrf1 PRIORITY 10 RULE Orifice2 IF  NODE DNode  Depth >= 0 THEN ORIFICE ORIFICE2 SETTING = Curve RuleOrf2 PRIORITY 10 Figure 1.  Two Orifice Solution Figure 2. Two Orifice solution to have control over the Orifice(s) at both the upstream and downstream nodes.  via Blogger http://www.swmm5.net/2013/08/how-to-use-two-control-curves-in-swmm-5.html

SWMM 5 Weir RTC Rules

Subject:   SWMM 5 Weir RTC Rules

SWMM 5 Weir RTC Rules by dickinsonre Subject:   SWMM 5 Weir RTC Rules This example SWMM 5 model closes a weir based on the depth at the upstream node of the Weir every 0.25 feet.  You can see the effect of the RTC rules using a Scatter plot of Weir Flow versus Weir Depth in SWMM 5 (Figure 1).   The Weir flows normally every 0.25 feet but shuts down three times using these rules which set the Weir Setting to 0.0 RULE Weir100 IF Node  WeirNode Depth > 1.75 AND Node WeirNode Depth < 2.0 THEN WEIR WEIR Setting = 0.0 Priority 2 RULE Weir101 IF Node  WeirNode Depth > 2.25 AND Node WeirNode Depth < 2.5 THEN WEIR WEIR Setting = 0.0 Priority 2 RULE Weir102 IF Node  WeirNode Depth > 2.75 AND Node WeirNode Depth < 3.0 THEN WEIR WEIR Setting = 0.0 Priority 2 RULE Weir103 IF Node  WeirNode Depth > 3.25 AND Node WeirNode Depth < 3.5 THEN WEIR WEIR Setting = 0.0 Priority 2 RULE Weir104 IF Node  WeirNode Depth > 3.75 AND Node WeirNode Depth < 4.0 THEN WEIR WEIR Setting = 0.0 Priority 2 Figure 1.  Scatter Graph of Weir flow versus Weir Node Depth. via Blogger http://www.swmm5.net/2013/08/swmm-5-weir-rtc-rules.html

How is the Orifice Setting Used in SWMM 5 RTC Rules?

Subject:  How is the Orifice Setting Used in SWMM 5 RTC Rules?

How is the Orifice Setting Used in SWMM 5 RTC Rules? by dickinsonre Subject:  How is the Orifice Setting Used in SWMM 5 RTC Rules? The Real Time Control Rule for Orifice Setting can be a function of a Setting constant, Setting from a Curve, Setting from a PID controller and a Setting from a Time Series (Figure 1).    The Setting affects the Full Depth of the Orifice at each time step.  The setting which ranges from 0 to 1 can either completely close or open theorifice (Figure 2).   You will have to use the equivalent in ICM or else the settings derived from the SWMM 5 time series need to be multiplied by the orifice depth to have the same effect in ICM that it had in SWMM 5.    Figure 1.  The Possibilities for defining the Setting of an Orifice in SWMM 5 from a H2OMAP SWMM RTC dialog.    Figure 2.  The Setting affects the Full Depth of the Orifice at each time step.  The setting which ranges from 0 to 1 can either completely close or open the orifice. via Blogger http://www.swmm5.net/2013/08/how-is-orifice-setting-used-in-swmm-5.htm

How Does a TYPE3 Variable Speed Pump Work in SWMM 5?

Subject:   How Does a TYPE3 Variable Speed Pump Work in SWMM 5?

In a SWMM 5 Type3 pump the flow is a function of the head difference between the downstream node head and the upstream node head (Figure 2) but the pump rules can be overwritten by a RTC Rule as in the attached example.   The RTC Controls in the example change the pump setting as a function of the depth in the Wet Well.  There is one pump between the Wet Well and Force Main but the Pump Setting varies from the RTC rules based on the depth in the Wet Well (Figure 1). As you can see in the composite Figure 2, the setting varies from 0, 1, 2 and 3 during the course of the simulation.

Figure 1.  How a Pump Flow is Calculated in SWMM 5.

Figure 2   RTC Rules and Schematic of a TYPE3 Pump in SWMM 5 with Force Mains Added along with three depth settings for a Variable Speed Pump or VSP.

How Does a TYPE3 Pump Work in SWMM 5?

Subject:   How Does a TYPE3 Pump Work in SWMM 5?

A SWMM 5 Type3 pump flow is a function of the head difference between the downstream node head and the upstream node head (Figure 1) but the pump rules can be overwritten by a RTC Rule as in the attached example in which the pump is only turned on then the flow in the upstream link 8040 is greater than 25 cfs.   Important components of the TYPE3 pump are: Surcharged Nodes to connect the Force Mains to the Pump (Figure 1), Force Mains (Figure 2), Wet Wells (Figure 3) and the TYPE three Pump Curve and the On and Off DEPTHs of the Pump (Figure 4).

Figure 1.  Connect a Pump to a Force Main by Using a Surcharge Node Depth.

Figure 2.  Define a Force Main Link if you want to use either Hazen-Williams or Darcy-Weisbach for the Friction Loss in the Link.

Figure 3.  A Wet Well at the Upstream End of the Pump can have either a Functional Area or a Tabular Area versus Depth Curve.

Figure 4   RTC Rules and Schematic of a TYPE3 Pump in SWMM 5 with Force Mains Added.

How Does a TYPE1 Pump Work in SWMM 5?

Subject:   How Does a TYPE1 Pump Work in SWMM 5?

How Does a TYPE1 Pump Work in SWMM 5? by dickinsonre Subject:   How Does a TYPE1 Pump Work in SWMM 5?  A SWMM 5 Type1 pump is called an offline pump but the name comes from SWMM 4 and the Pump is controlled by volume instead of depth or head as in the SWMM 5 TYPE2, TYPE3 and TYPE4 Pumps.  The attached example SWMM 5 model has an offline storage node that pumps flow INTO the Offline Storage unit during high flow and FROM the Offline Storage Unit during low flow.  The SWMM 5 Real Time Control (RTC) rules determine which of the two pumps operate based on the flow in an upstream link (Figure 1).  Figure 1.   RTC Rules and Schematic of an OffLine Pump in SWMM 5. via Blogger http://www.swmm5.net/2013/08/how-does-type1-pump-work-in-swmm-5.html

What are the Equations for Weirs in SWMM 5, Part 2?

Subject:   What are the Equations for Weirs in SWMM 5, Part 2?

What are the Equations for Weirs in SWMM 5, Part 2? by dickinsonre Subject:   What are the Equations for Weirs in SWMM 5, Part 2?  There are four types of Weirs in SWMM 5:  Transverse, Sideflow, V Notch and Trapezoidal.   The trapezoidal weir is a combination of the Sideflow and V Notch Weir and the Sideflow acts like a Transverse Weir when the flow is reversed (Figure 1).  The Weirs can have zero, one or two end contractions (Figure 2) and the Weir Length is a function of the Weir Setting and Horizontal Weir Length.  A V Notch weir works as Trapezoidal Weir when the Weir RTC Setting is less than 1.0   Figure 1.   Weir Equations in SWMM 5  Figure 2.   Valid Number of End Contractions   Figure 3.  Weir Length Calculations   via Blogger http://www.swmm5.net/2013/08/what-are-equations-for-we

How to Approximate a Timer in the RTC Rules of SWMM 5

Subject:   How to Approximate a Timer in the RTC Rules of SWMM 5

How to Approximate a Timer in the RTC Rules of SWMM 5 by dickinsonre Subject:   How to Approximate a Timer in the RTC Rules of SWMM 5  SWMM 5 does not have a explicit timer in its Real Time Control (RTC) rules but you can approximate it by using a Control Curve as in the attached example model.  The Control Curve will modify the setting of the Weir by the Inflow to the Storage node.  You can have normal weir flow settings based on the invert elevation of the weir and the Surface node water surface elevation but in addition you can control the weir setting by:  1.   Closing the weir when the inflow is low, 2.   Closing the weir by staggered Storage node depth, 3.   Opening the weir gradually when the inflow increases 4.   Closing the weir by a combination of Node Depth IF statements and Control Curve rules  For example, you can have the Weir Setting controlled the Node Depth,  Link Inflow and Node Inflow  simultaneously approximately with the depth and the inflow parameters closing the weir by proxy instead of by time since the closing. via Blogger http://www.swmm5.net/2013/08/how-to-approximate-timer-in-rtc-rules.html

gate_timer.INP Download this file

How to Approximate a Timer in the RTC Rules of SWMM 5.docx Download this file

How to see the effect of the Pump Setting in the RTC Rules of InfoSWMM and H20MAP SWMM

Subject:  How to see the effect of the Pump Setting in the RTC Rules of InfoSWMM and H20MAP SWMM

Step 1.   Pump Startup and Shutoff Depth

Depths to turn the Pump On and turn the Pump Off.  In this example, the pump will be off when the Wet Well Depth is less than 2 feet, the Pump will be off between a Wet Well Depth between 2 and 5.75 feet if the Pump is currently Off and the Pump will be On between a Wet Well Depth between 5.75 and 2 feet.

Step 2.   RTC Rule for the Pump Setting when the Wet Well Depth is less than 6.25 feet.  We need to add the AND statement so that the setting is only reset when the Pump is On.   You do not want the pump setting to be reset when the pump should be off.

Result 1:  The Pump Speed Ratio tells you the Pump Setting

Result 2:  RTC Control Rules in the RPT File if you click on Show Control Actions

Result 3:   The depth at the Wet Well and the Flow in the Pump

 Result 4:  A mixed graph of the Wet Well Depth and Pump Flow shows the effect of the RTC.

Result 5:  The RTC Rule can also been seen flow to the Pump Curve.

Example VSP Pump in SWMM 5 - Version 1

Subject:   Example VSP Pump in SWMM 5 - Version 1

Here is one way to model multiple pumps between the same downstream and upstream nodes using the pump curves and the Real Time Control Rules (RTC) in SWMM 5.  Here are the steps:

1.   Enter the data for three pumps in the browser by using the Add Pump Icon
2.   Enter three Pump Head/Flow Curves so that the 2^nd and 3^rd Pump Curves are the sum of the flows in the 1^st and 2^nd Pumps together and the sum of the flows in the 1^st, 2^nd and 3^rd respectively for the 2^nd and 3^rd Pump Curves

3.   Enter a RTC Rule in the Control Editor so that when the 1^st Pump is turned on – the 2^nd and 3^rd Pump is turned off
4.   Enter a RTC Rule in the Control Editor so that when the 2^nd  Pump is turned on – the 1^st  and 3^rd Pump is turned off
5.   Enter a RTC Rule in the Control Editor so that when the 3^rd  Pump is turned on – the 1^st and 2^nd Pump is turned off

Using these rules you can see that for the 1^st Pump turns on when the Node WetWell has a depth below 2 feet, the 2^nd Pump turns on when the Node is between a depth of 2 to 5 feet and the 3^rd Pump turns on when the Node Depth is above 5 feet.

RULE Pump1
IF Node WetWell Depth <= 2
THEN PUMP PUMP2 STATUS = OFF
AND PUMP PUMP3 STATUS = OFF
Priority 1

RULE Pump2
IF Node WetWell Depth > 2
AND Node WetWell Depth <= 5
THEN PUMP PUMP1 STATUS = OFF
AND PUMP PUMP3 STATUS = OFF
Priority 2

RULE Pump3
IF Node WetWell Depth > 5
THEN PUMP PUMP1 STATUS = OFF
AND PUMP PUMP2 STATUS = OFF
Priority 3

How RTC Rules are Set in SWMM5, InfoSWMM and H2OMAP SWMM

Subject:   How RTC Rules are Set in SWMM5, InfoSWMM and H2OMAP SWMM

SWMM 5 Clocktime RTC Rules for Pumps, Weirs and Orifices

Subject:  SWMM 5 Clocktime RTC Rules for Pumps, Weirs and Orifices

You can use the Control or RTC rules in SWMM 5 to adjust the settings of the weirs, pumps and orifices based on the clock time each day of your simulation.  Here is an example that will adjust orifice height every ½ hour for 7 orifices at one time using two sets of rules.

RULE R1a 
; Half hour setting
IF SIMULATION CLOCKTIME = 0:30:00 
OR SIMULATION CLOCKTIME = 1:30:00  
OR SIMULATION CLOCKTIME = 2:30:00 
OR SIMULATION CLOCKTIME = 3:30:00 
OR SIMULATION CLOCKTIME = 4:30:00 
OR SIMULATION CLOCKTIME = 5:30:00 
OR SIMULATION CLOCKTIME = 6:30:00 
OR SIMULATION CLOCKTIME = 7:30:00 
OR SIMULATION CLOCKTIME = 8:30:00 
OR SIMULATION CLOCKTIME = 9:30:00 
OR SIMULATION CLOCKTIME = 10:30:00
OR SIMULATION CLOCKTIME = 11:30:00
OR SIMULATION CLOCKTIME = 12:30:00 
OR SIMULATION CLOCKTIME = 13:30:00  
OR SIMULATION CLOCKTIME = 14:30:00 
OR SIMULATION CLOCKTIME = 15:30:00 
OR SIMULATION CLOCKTIME = 16:30:00  
OR SIMULATION CLOCKTIME = 17:30:00 
OR SIMULATION CLOCKTIME = 18:30:00 
OR SIMULATION CLOCKTIME = 19:30:00 
OR SIMULATION CLOCKTIME = 20:30:00 
OR SIMULATION CLOCKTIME = 21:30:00 
OR SIMULATION CLOCKTIME = 22:30:00
OR SIMULATION CLOCKTIME = 23:30:00
THEN ORIFICE R1 SETTING = 0.90
AND  ORIFICE R2 SETTING = 0.90
AND  ORIFICE R3 SETTING = 0.90
AND  ORIFICE R4 SETTING = 0.90
AND  ORIFICE R5 SETTING = 0.90
AND  ORIFICE R6 SETTING = 0.90
AND  ORIFICE R7 SETTING = 0.90

RULE R1b
; hour setting
IF SIMULATION CLOCKTIME = 0:00:00
OR SIMULATION CLOCKTIME = 1:00:00
OR SIMULATION CLOCKTIME = 2:00:00
OR SIMULATION CLOCKTIME = 3:00:00
OR SIMULATION CLOCKTIME = 4:00:00
OR SIMULATION CLOCKTIME = 5:00:00
OR SIMULATION CLOCKTIME = 6:00:00
OR SIMULATION CLOCKTIME = 7:00:00
OR SIMULATION CLOCKTIME = 8:00:00
OR SIMULATION CLOCKTIME = 9:00:00
OR SIMULATION CLOCKTIME = 10:00:00
OR SIMULATION CLOCKTIME = 11:00:00
OR SIMULATION CLOCKTIME = 12:00:00 
OR SIMULATION CLOCKTIME = 13:00:00
OR SIMULATION CLOCKTIME = 14:00:00 
OR SIMULATION CLOCKTIME = 15:00:00
OR SIMULATION CLOCKTIME = 16:00:00
OR SIMULATION CLOCKTIME = 17:00:00
OR SIMULATION CLOCKTIME = 18:00:00 
OR SIMULATION CLOCKTIME = 19:00:00 
OR SIMULATION CLOCKTIME = 20:00:00 
OR SIMULATION CLOCKTIME = 21:00:00 
OR SIMULATION CLOCKTIME = 22:00:00 
OR SIMULATION CLOCKTIME = 23:00:00
THEN ORIFICE R1 SETTING = 0.5
AND  ORIFICE R2 SETTING = 0.5
AND  ORIFICE R3 SETTING = 0.5
AND  ORIFICE R4 SETTING = 0.5
AND  ORIFICE R5 SETTING = 0.5
AND  ORIFICE R6 SETTING = 0.5
AND  ORIFICE R7 SETTING = 0.5

InfoSWMM Note About Pump Wet Wells

Subject:  Wet Well Maximum depths and Pump Start and Pump Off Depths

  The Wet Well has

·         An invert elevation and

·         A Maximum Depth

The Pumps have

·         Pump On Depth

·         Pump Off Depth

·         Pump Head – Discharge Curve or

·         RTC Rules

The Links have a

·         Invert Elevation into the Wet Well and

·         Invert Elevation into the Downstream Force Main

·         Crown Elevation

Figure 1. Wet Well  Maximum Depth

Opening and Closing an Orifice with a Time Series Setting

Opening and Closing an Orifice with a Time series Setting

An example of RTC rules in SWMM 5

Orifice Open and Close Speed and the Target Setting in SWMM 5

Orifice Open and Close Speed and the Target Setting
In SWMM 5 there is an orifice parameter called setting which opens or closes the orifice opening by modifying the depth of the orifice. The setting is based either on a RTC rule of the orifice or the Flap Gate condition of the orifice and can be between 0 and 1. Closed is 0; Open is 1. The difference is that the target setting is what the setting should be based on the condition of the Flap Gate or the RTC Rules and the setting is the value actually used in the model.
The open and close speed of the orifice modifies the orifice setting by changing the orifice setting based on the open and closing speed using the equation:
New Orifice Setting = Old Orifice Setting + (Target Setting – Orifice Setting) * Time Step / Orifice Open and Close Speed
If your target setting and the current orifice setting are both 1 or 0 then the orifice Open and Close option does not change the orifice setting. New Setting equals Old Setting in that case. If the target and setting are out of phase then the Open and Close Option will function correctly. For example, if the Open and Close Speed is 1 hour then the orifice setting will open and close in a one hour period. The table shown below shows how the orifice setting changes as a function of the speed and the difference between the target and orifice settings. The setting starts out open but the target says closed – the orifice then closes over a 1 hour period. At one hour the target setting is 1 and the orifice will then open over a one hour period.
Table - Link OR1@82309b-15009b
Setting Target
Days Hours
0 00:00:00 1.00 0.00
0 00:15:00 0.74 0.00
0 00:30:00 0.50 0.00
0 00:45:00 0.25 0.00
0 01:00:00 0.00 0.00
0 01:15:00 0.25 1.00
0 01:30:00 0.50 1.00
0 01:45:00 0.75 1.00
0 02:00:00 1.00 1.00
0 02:15:00 0.75 0.00
0 02:30:00 0.50 0.00
0 02:45:00 0.25 0.00
0 03:00:00 0.00 0.00
0 03:15:00 0.00 0.00
0 03:30:00 0.00 0.00
0 03:45:00 0.00 0.00

Example rule for the opening and closing of the orifice

Here is an example Real Time Control (RTC) rule for the opening and closing of an orifice.
RULE Orifice1
IF SIMULATION CLOCKTIME >= 01:00:00
AND SIMULATION CLOCKTIME <= 2:00:00
THEN ORIFICE OR1@82309b-15009b SETTING = 1
ELSE ORIFICE OR1@82309b-15009b SETTING = 0
PRIORITY 1
; Opens up the orifice at hour 1 of the simulation

Lead and Lag Pump Options in SWMM 5

Introduction: If you have a lead and lag pump connecting the same upstream and downstream nodes the normal behavior for the two pumps is to have the the lead pump turn on first followed by the lag pump. The turn on and turn off depths for the pumps determine when the pumps turn of. The pump will work as a simple lead and lag pump based on a wet well elevation without any real time controls.

If you want to add real time controls (RTC) to the lead and lag pumps you can add more sophisticated controls. For example, if you wanted to turn on and off the lead pump at successive time steps then you can add these RTC rules

; New Real Time Control (RTC) Rules

RULE RULE-1

IF PUMP LEAD_PUMP STATUS = ON

AND PUMP LAG_PUMP STATUS = ON

THEN PUMP LEAD_PUMP STATUS = OFF

PRIORITY 1.000000

RULE RULE-2

IF PUMP LEAD_PUMP STATUS = OFF

AND PUMP LAG_PUMP STATUS = ON

THEN PUMP LEAD_PUMP STATUS = ON

PRIORITY 1.000000

RULE RULE-3

IF PUMP LEAD_PUMP STATUS = OFF

AND PUMP LAG_PUMP STATUS = ON

THEN PUMP LEAD_PUMP STATUS = ON

PRIORITY 1.000000

If you want to add a pattern of 2 time steps and 1 time step off for both pumps then you can add this RTC new rule to control the lag pump:

RULE RULE-4

IF PUMP LEAD_PUMP STATUS = OFF

AND PUMP LAG_PUMP STATUS = ON

THEN PUMP LAG_PUMP STATUS = OFF

PRIORITY 1.000000