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

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

Node Comparison in InfoSWMM and InfoSewer

Node Comparison in InfoSWMM and InfoSewer by dickinsonre Note:  Node Comparison in InfoSWMM and InfoSewer  1)    Is there an option to set the manhole sealing method (i.e. locked  or unlocked) in InfoSWMM?  You set the Surcharged depth to a positive value to prevent flooding and keep the pipes under pressure.  You will still have flooding once the water surface elevation reaches the maximum depth + surcharge depth.  Unlike inInfoSewer the depths are not unlimited.  2)    Is defining manhole diameter in InfoSWMM available?  You can set the default surface area of a node or make it a storagenode.    3)    Does InfoSWMM allow me to create parallel pipes with the same  attributes similar to InfoSewer?  You can set the number of barrels in the attribute browser of DB Editor in InfoSWMM.    4)    Can you please confirm that the only element allowed to leave a  storage unit in InfoSWMM is a pump?  No, this is not true.  You can have a gravity main, orifice or weir leave a storage pond or lake.  5)    Is there a tool to check for pipe diameter discrepancies in  InfoSWMM similar to InfoSewer?  Yes, we have a similar Engineering Review and Network Audit Tools 6)    For load patterns, I do not see an option between stepwise and  continuous in InfoSWMM, or is there?  InfoSWMM really only has stepwise linear DWF pattern though you can have a time series of inflows as well which gives you complete flexibility.  7)    Does InfoSWMM offer modeling I&I using pipe length, pipe surface  area etc… like in InfoSewer?   You can but there in not an easy translation,  You have Rainfall Induced Infiltration at a Node. You can relate this to the pipe length but it is not straightforward.  8)    Is steady state simulation and design simulation available in  InfoSWMM similar to InfoSewer?  You can do Steady State easily but design uses a Genetic Algorithm technique if you have InfoSWMMSuite. via Blogger http://www.swmm5.net/2013/08/node-comparison-in-infoswmm-and.html

SWMM5 Weir Rules, Head Calculations and Weir HGL Plots

Note:  SWMM5 Weir Rules and Head Calculations

This note attempts to explain both how the head upstream and the head downstream of a weir in SWMM 5 is calculated compared to the weir crest elevation and also to explain how the weir is presented in the HGL plot of SWMm 5.  There has been confusion in the past concering how the weir is shown compared to the actual weir calculations.  The node head is calculated obviously at both ends of the weir but the head over the weir is always based on H1-Crest or H2-Crest (Figure 1) and hence the weir should look flat – to the weir the downstream head is important but NOT the downstream node invert so the weir really is flat and should look flat in the HGL Profile across the weir (Figure 2).    The crest elevation is always relative to the upstream node invert elevation NOT the downstream node invert elevaation

Figure 1.  How the Head across a Weir is calculated in SWMM 5

Figure 2.   HGL Profile across a Weir in SWMM 5.0.022.  The black line should be shown flat.

Weir and Orifice Flow Equations for a Weir in SWMM 5 by dickinsonre Note:  Weir and Orifice Flow Equations for a Weir in SWMM 5 If you use a weir in SWMM 5 then two flow equations are used 1.       The weir uses the weir flow equation when the head at the weir is between the invert elevation of the weir and the crown of the weir and 2.      An orifice equation when the head is above the weir crown or the weir is submerged. via Blogger http://www.swmm5.net/2013/08/weir-and-orifice-flow-equations-for.html

Weir and Orifice Flow Equations for a Weir in SWMM 5

Note:  Weir and Orifice Flow Equations for a Weir in SWMM 5

If you use a weir in SWMM 5 then two flow equations are used

1.       The weir uses the weir flow equation when the head at the weir is between the invert elevation of the weir and the crown of the weir and
 2.      An orifice equation when the head is above the weir crown or the weir is submerged.

Weir and Orifice Flow Equations for a Weir in SWMM 5 by dickinsonre

Note:  Weir and Orifice Flow Equations for a Weir in SWMM 5

If you use a weir in SWMM 5 then two flow equations are used

1.       The weir uses the weir flow equation when the head at the weir is between the invert elevation of the weir and the crown of the weir and

2.      An orifice equation when the head is above the weir crown or the weir is submerged.

via Blogger http://www.swmm5.net/2013/08/weir-and-orifice-flow-equations-for.html

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

Detention Basin Basics in SWMM 5

Subject:  Detention Basin Basics in SWMM 5

What are the basic elements of a detention pond in SWMM 5?  They are common in our backyards and cities and just require a few basic elements to model.  Here is a model in SWMM 5.0.022 that even has a fountain in the real pond – which we not model for now.   The components of the model are:

1.   An inlet to the pond with a simple time series – a subcatchment can be added to it in a more complicated model but for now we will just have a triangular time series,
2.   A pipe to simulate the flow into the pond from the inlet,
3.   A Storage Node to simulate the Pond that consists of a tabular area curve to estimate the depth and area relationship,
4.   A Storage Node to simulate the Outlet Box of the Pond
5.   Two Small Rectangular Orifices to simulate the low flow outflow from the pond at an elevation less than the weir
6.   A large rectangular orifice to simulate the normal inflow to the Box
7.   A rectangular weir to simulate the flow into the box when the pond water surface elevation is above the box
8.   The outlet of the Box is a circular link with a Free outfall as the downstream boundary condition
9.   The flow graph in the image shows the flow into the box starts from the two small orifices, next from the large orifice and finally from the top of the box or the weir.

http://api.ning.com/files/ZtT72Lr8bEOi83U3XrtN9x2vsbK-V--dbjfMZOFEzO4M22pEDeFsuOE5GdQV8Z354OTHNEpjEZwvHPXYyhvbRqPHSxM4DUjv/detetention_pond.INP

Diversion LInks in SWMM 5 and 5.0.021

Subject:  Diversion Links in SWMM 5 and 5.0.021

Diversion links in SWMM 5 are Pumps (5 types), Orifices (2 types), Weirs (4 types) and Outlets (3 types).
  

Figure 1.  Diversion Links in SWMM 5

Types of Nodes and Links in SWMM 5 - with Emojis

Subject: 📌 Types of Nodes and Links in SWMM 5

Introduction: 🚀 SWMM 5 is a powerful tool used for simulating the hydrology and hydraulics of urban drainage systems. Central to its modeling capabilities are the nodes and links that constitute the drainage network. Let's delve deeper into understanding these critical components.

Nodes in SWMM 5 📍: Nodes are pivotal points or junctions in the drainage system where water collects and gets distributed. They can be categorized as:

1. Junctions 🚇: These are points where multiple links come together. They represent the convergence or divergence of flow paths. In SWMM 5, there's only one type of junction, but it plays a crucial role in defining the flow dynamics.

2. Storages 🛢️: Storages are areas where water is temporarily held before it's released at a controlled rate. In SWMM 5, there are three types of storage:

   • Surface Storage: Represents flat areas like ponds.
   • Tank Storage: Denotes vertical cylindrical tanks.
   • General Storage: A more flexible form that can represent any shape.

3. Dividers 🚧: Dividers distribute incoming flow into multiple paths. While they can be used in the dynamic wave solution of SWMM 5, they only help divide the flow in the kinematic wave solution. There are four types of dividers in SWMM 5, each with its unique characteristics.

4. Outfalls 🌊: Outfalls represent points where water exits the system, either into a larger body of water or another system. SWMM 5 offers five types of outfalls, each designed to simulate different outflow conditions.

Links in SWMM 5 ⛓️: Links are the channels or pathways that connect nodes and facilitate the flow of water between them. They include:

1. Conduits 🚰: These are pipes or channels that transport water between nodes. They can vary in shape, size, and material.

2. Pumps 🔄: Pumps are devices that move water from one node to another, typically from a lower elevation to a higher one.

3. Orifices ⚙️: Orifices control the flow of water between nodes based on the opening size and elevation.

4. Weirs 🌁: Weirs are barriers that redirect or measure flow. They can be sharp-crested, broad-crested, or even compound.

5. Outlets 🚪: Outlets control the discharge of water from a node based on the depth or head of water.

Conclusion 🌟: Understanding nodes and links in SWMM 5 is paramount for effective modeling. These components are the building blocks of the drainage system, and their accurate representation ensures reliable and meaningful simulation results. 📊🛠️

Figure 1.  Node and Link Objects in SWMM 5

Figure 2:  Node Objects in SWMM 5

PID Control in SWMM 5 for an Orifice

Click here to download:

extran_pid_3_master.inp (47 KB)

Subject: PID Control in SWMM 5 for an Orifice

The blog http://swmm5.blogspot.com/2010/12/pid-control-in-swmm-5-for-type-3-pump.htmldescribes the Function getPIDSetting which returns the PID setting at each time step. The PID parameter set contains three values -- a proportional gain coefficient, an integral time (in minutes), and a derivative time (in minutes) which are kp, ki and kd, respectively. More about the theory of PID controllers can be found at http://en.wikipedia.org/wiki/PID_controller.

Here is an example PID Rule that will keep the node depth at 5 feet in a SWMM 5 model by changing the Orifice Setting. The Orifice setting opens and closes the orifice over time. The example file is attached in this blog. In this particular example, you can reduce the oscillations about the 5 foot rule level by lowering the integral time and derivative time coefficients in the PID control rule. An important note is that for Weirs and Orifices the setting is bounded to be between 0 and 1. If the Orifice or Weir cannot handle the upstream node inflow then the PID control will not be able to meet the depth goal in the node. For example, in the example file, an orifice depth of 2 feet is not enough to meet the upstream node depth goal of 5 feet but a 3 foot orifice is large enough for the PID control to meet its stated goal of 5 feet. The PID control will only work if the link doing the controller has enough flow and depth flexibility.

RULE PID_Orifice

; the PID controller adjusts the orifice opening to have a

; depth of 3 feet in Node 82309b

IF NODE 82309b DEPTH <> 5

THEN ORIFICE OR1@82309b-15009b SETTING = PID 10 -0.01 -0.01

; kp ki kd

PRIORITY 1