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MWH Soft Ships InfoWorks TS for Comprehensive Hydraulic Transient Analysis of Water Distribution Systems

Posted by Robert Dickinson on October 5, 2010 at 12:49pm

MWH Soft Ships InfoWorks TS for Comprehensive Hydraulic Transient Analysis of Water Distribution Systems

Highly Anticipated Release Equips Engineers with Unprecedented Transient Modeling Capabilities for Better Decision-Making

Broomfield, Colorado USA, October 5, 2010

MWH Soft, a leading global innovator of wet infrastructure modeling and simulation software and technologies, today announced the worldwide release of InfoWorks TS for advanced hydraulic transient analysis. The groundbreaking release gives InfoWorks WSusers direct access to the industry’s fastest, most comprehensive and widely acclaimed pressure surge analysis application, with unsurpassed power to help them better preserve distribution system integrity and avert potential problems. The new product reflects MWH Soft’s vanguard position in the water industry and its continuing commitment to delivering pioneering technology for enhancing the safety and reliability of the world’s water supply.

Anticipating and controlling transient response is critical to ensuring the protection, integrity, and effective/efficient operation of water distribution systems. Transient responses can introduce pressures of sufficient magnitude (upsurge) to burst pipes and damage equipment. The resulting repercussions can include extended service outages and loss of property and life. Transient responses can also produce sub-atmospheric pressures (downsurge) that can force contaminated groundwater into the distribution system at a leaky joint, crack or break, leading to grave health consequences. Sustained sub-atmospheric pressures may also lead to cavitation and water column separation, resulting in severe “water hammer” effects as the vapor cavity collapses.

The state-of-the-art, full-featured InfoWorks TS transient flow analysis solution addresses every facet of pressure surge analysis and its role in utility infrastructure management and protection, delivering the highest rate of return in the industry. It provides the engineer-friendly framework needed to quickly assess the effects of pump station power failures, pump startup, valve closures, rapid demand and pump speed changes, and the efficacy of any combination of surge protection devices. The program also accurately simulates transient cavitation and water column separation, evaluates their intensity, and estimates their potential effects on the system.

Armed with this information, water utilities can more accurately predict the development of unacceptable operating conditions in their distribution systems, identify vulnerable areas and risks, evaluate and design sound protective measures, and determine improved operational plans and security upgrades. InfoWorks TS also delivers blazing simulation speed, making transient analysis an even easier and more enjoyable task.

“Water utilities and engineering consulting firms around the world rely on MWH Soft’s superior end-to-end modeling and design solutions to manage and operate better, safer systems,” said Paul F. Boulos, Ph.D, Hon.D.WRE, F.ASCE, President and Chief Operating Officer of MWH Soft. “By augmenting our popular InfoWorks WS with powerful hydraulic transient modeling capabilities, we are creating a comprehensive tool kit for the waterworks engineer. This milestone solution is the only analysis, design and management software users need to work faster and smarter in a competitive environment — not only to power system performance, but to safeguard critical infrastructures and maximize their effectiveness in protecting public health. MWH Soft is very proud to offer this revolutionary product to our clients.”

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Science Daily - Alarming Increase in Flow of Water Into Oceans Due to Global Warming, Accelerated Cycle of Evaporation, Precipitation

Posted by Robert Dickinson on October 4, 2010 at 8:24pm

Alarming Increase in Flow of Water Into Oceans Due to Global Warming, Accelerated Cycle of Evaporation, Precipitation

ScienceDaily (Oct. 4, 2010) — Freshwater is flowing into Earth's oceans in greater amounts every year, a team of researchers has found, thanks to more frequent and extreme storms linked to global warming. All told, 18 percent more water fed into the world's oceans from rivers and melting polar ice sheets in 2006 than in 1994, with an average annual rise of 1.5 percent.


"That might not sound like much -- 1.5 percent a year -- but after a few decades, it's huge," said Jay Famiglietti, UC Irvine Earth system science professor and principal investigator on the study, which will be published this week inProceedings of the National Academy of Sciences. He noted that while freshwater is essential to humans and ecosystems, the rain is falling in all the wrong places, for all the wrong reasons.

"In general, more water is good," Famiglietti said. "But here's the problem: Not everybody is getting more rainfall, and those who are may not need it. What we're seeing is exactly what the Intergovernmental Panel on Climate Change predicted -- that precipitation is increasing in the tropics and the Arctic Circle with heavier, more punishing storms. Meanwhile, hundreds of millions of people live in semiarid regions, and those are drying up."

In essence, he said, the evaporation and precipitation cycle taught in grade school is accelerating dangerously because of greenhouse gas-fueled higher temperatures, triggering monsoons and hurricanes. Hotter weather above the oceans causes freshwater to evaporate faster, which leads to thicker clouds unleashing more powerful storms over land. The rainfall then travels via rivers to the sea in ever-larger amounts, and the cycle begins again.

The pioneering study, which is ongoing, employs NASA and other world-scale satellite observations rather than computer models to track total water volume each month flowing from the continents into the oceans.

"Many scientists and models have suggested that if the water cycle is intensifying because of climate change, then we should be seeing increasing river flow. Unfortunately, there is no global discharge measurement network, so we have not been able to tell," wrote Famiglietti and lead author Tajdarul Syed of the Indian School of Mines, formerly of UCI.

"This paper uses satellite records of sea level rise, precipitation and evaporation to put together a unique 13-year record -- the longest and first of its kind. The trends were all the same: increased evaporation from the ocean that led to increased precipitation on land and more flow back into the ocean."

The researchers cautioned that although they had analyzed more than a decade of data, it was still a relatively short time frame. Natural ups and downs that appear in climate data make detecting long-term trends challenging. Further study is needed, they said, and is under way.

Other authors are Don Chambers of the University of South Florida, Joshua Willis of the Jet Propulsion Laboratory in Pasadena, and Kyle Hilburn of Remote Sensing Systems in Santa Rosa, Calif. Funding is provided by NASA.

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Link Area Types in SWMM 5

Posted by Robert Dickinson on October 2, 2010 at 9:30am

Note: There are 7 Link flow classification classes that are used to assign the area of the link to the upstream and downstream nodes of the link. The classes used during the simulation of the model are shown in the Link Classification Table in the RPT Report File. The supercritical class is the same as the subcritical assignment. The supercritical is a class of subcritical with a Froude number over 1.


Class

Description

Link Area Assignment

0 Dry conduit

1/2 Upstream and 1/2 Downstream Node

1 Upstream end is dry

1/2 Downstream Node

2 Downstream end is dry

1/2 Upstream Node

3 Sub-critical flow

1/2 Upstream and 1/2 Downstream Node

4 Super-critical flow

1/2 Upstream and 1/2 Downstream Node

5 Free-fall at upstream end

1/2 Downstream Node

6 Free-fall at downstream end

1/2 Upstream Node

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Orifice Critical Depth for Separating Weir Flow from Orifice Flow for Bottom Outlet Orifices

Posted by Robert Dickinson on October 2, 2010 at 9:09am

Note: Orifice Critical Depth for Separating Weir Flow from Orifice Flow for Bottom Outlet Orifices

The Critical height is the opening where weir flow turns into orifice flow. It equals (Co/Cw)*(Area/Length) where Co is the orifice coeff., Cw is the weir coeff/sqrt(2g), Area is the area of the opening, and Length = circumference of the opening. For a basic sharp crested weir, Cw = 0.414. All of the units are based on the internal SWMM 5 units of American Standard.

For a circular orifice the Critical Height is:

Critical Height = Orifice Discharge Coefficient / 0.414 * Orifice Opening / 4

For a rectangular orifice the Critical Height is:

Critical Height = Orifice Discharge Coefficient / 0.414 * (Orifice Opening*Width) / (2.0*(Orifice Opening+Width))

The Orifice Critical Depth changes dynamically as the orifice is opening and closing for a bottom outlet orifice. The critical depth separating the orifice weir flow from orifice flow for a side outlet orifice is the height of the orifice.

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The four cross sectional areas in a link of SWMM 5

Posted by Robert Dickinson on October 1, 2010 at 8:24pm

Note: Four cross sectional areas are used in a link of SWMM 5. The weighted hydraulic radius (Rwtd) is a function of the Froude Number of the link and the upstream and downstream hydraulic radius. The Rwtd value is used in the computation of the friction slope or the dq1 term in the file dynamic.c

dq1 = Time Step * RoughFactor / Rwtd^1.333 * |Velocity|

The weighted area (Awtd) is used in the dq2 term of the St. Venant equation:

dq2 = Time Step * Awtd * (Head Downstream – Head Upstream) / Link Length

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Three Depths in A Link in SWMM 5

Posted by Robert Dickinson on October 1, 2010 at 7:00pm

Note: An explanation of the three depths in a Link in SWMM 5 and a plot of the upstream, middle and downstream link depth. The middle depth is an average of the upstream and downstream link depths. The plot of the variable depth or the middle depth is always between the upstream and downstream depths. All three depths are used in the computation of the St. Venant Flow in SWMM 5. The upstream area is a function of the upstream depth and the downstream area is a function of the downstream depth.


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


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Time Base is T + T*K from the Time(T) and Storage (K) values

Posted by Robert Dickinson on October 1, 2010 at 5:30pm

Note: Each of the RDII UH’s has a base time for the convolution of the RDII from each UH. The Time Base is T + T*K from the Time(T) and Storage (K) values used in the RTK data. In this particular case:

· The Fast UH has a time base of 22 hours,

· The Medium UH has a time base of 430 hours, and

· The Slow UH has a time base of 4212 hours.

If this is altered as in the bottom image you can see the difference in the total RDII I&I Flow

· The Fast UH has a time base of 22 hours,

· The Medium UH has a time base of 36 hours, and

· The Slow UH has a time base of 52 hours.

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H2OMAP-Sewer - FM Split Issue

Posted by Robert Dickinson on October 1, 2010 at 4:48pm

Note: One method would be to add a duplicate Wet Well/Pump/Force Main set of links to pass the flow from the upstream Force Main to the two downstream Force Mains (FM). The pump should be fixed capacity to handle all of the split GM flows. In this particular example the flows are split 50/50 to links 25 and 35 after leaving the loading manhole 24.

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Pumps and Force Mains in InfoSWMM

Posted by Robert Dickinson on October 1, 2010 at 11:56am

Note: A pump is modeled in InfoSWMM somewhat akin to InfoSewer. You have a Wetwell connected to a Pump which in turn is connected to a Force Main. You can decide wheter a pipe is a Force Main or a Gravity Main by using the Atribute Browser and selecting Yes for Force Main and entering a FM Roughness.

You can also use the PickAx tool in the Attibrute Browser to convert the node from a Manhole to a WetWell / Storage node.

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RDII UH Storage Sensitivity

Posted by Robert Dickinson on October 1, 2010 at 11:31am

Note: The initial abstraction in the three RDII UH’s vary between 0 storage and maximum storage (Dmax). The speed of storage recovery is governed by the parameter Drec. You can see the sensitivity of this parameter in this graph of the UH Storage.

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The Effect of the Hydrology Time Step on RDII Flow

Posted by Robert Dickinson on October 1, 2010 at 9:30am

Note: The wet hydrology time step and the report time step should be adjusted together to generate the smoothest RDII flow at your nodes. The three images show below show:

1.If you hydrology time step equals your rainfall time step then the RDII flow will have a step function appearance or your flows in this case will be constant for one hour or the rainfall interval,

2.If you choose a smaller hydrology time step then the flows will be smoother (2nd image), but

3.If the report time step is much less than the hydrology time step then the flows will still be stepwise linear for the hydrology time step size.

When picking a hydrology time step for continuous simulation you should probably pick a value of about 5 minutes so that the generated flows are smooth but not so small that a lot of time is used in the RDIi convolution process to generate the 3 units hydrographs for RDII.

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Conduit Lengthening in SWMM 5

Posted by Robert Dickinson on September 26, 2010 at 1:00pm

Conduit Lengthening in SWMM 5


If you use the conduit lengthening option in SWMM 5 then your short conduits will be lengthened based on the CFL or explicit time step criterion. Any conduits in which the Length Factor or the courant time step link length over the original length is greater than 1 will be lengthened and will have its roughness lowered so that the conduit is hydraulically the same at full conduit depth. The full area, full width and full hydraulic radius stay the same in the modified link – only the length, slope and roughness are altered.


Length Factor = (Wave Celerity + Full Depth Velocity) * Time Step / Conduit Length, and for those links in which the Length Factor is greater than 1


New Roughness = Old Roughness / (Length Factor) ^1/2


New Slope = Old Slope / Length Factor


A few metric's for showing how this option has altered the network are shown in the figure below:

1. The most important is the increase in Network full volume as you never want to drastically alter the volume of your network,

2. The number of conduits modified along with the new mean slope (lower) and the new total conduit length are important indicators,

3. The mean wave celerity, full flow velocity and courant time step mean give the user some idea of the optimal time step for the simulation.

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LPS Output Units when the Inflow is CMS

Posted by Robert Dickinson on September 21, 2010 at 7:34pm
LPS Output Units when the Inflow is CMS

1.The inflow time series is in units of CMS,

2.If you set the internal units to LPS in Run Manager,

3.Set the output units to LPS in Output Unit Manager,

4.Add a Scale multiplier of 1000 in the Inflows DB Table then

The inflows do not have to be altered, the internal model flows will LPS, the velocity will be m/s with 6 decimal places in the RPT file and the flows will be LPS with 3 decimal places in the RPT file.

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MWH Soft Adds New Channel Partners in Philippines and Turkey to Its Global Network

Posted by Robert Dickinson on September 21, 2010 at 12:29pm

MWH Soft Adds New Channel Partners in Philippines and Turkey to Its Global Network

Company Expands Into Two Rapidly Growing Markets

Broomfield, Colorado USA, September 21, 2010 — MWH Soft, a leading global innovator of wet infrastructure modeling and simulation software and technologies, today announced that Geodata Systems Technologies, Inc., and Universal Information Technologies have been named Certified Channel Partners for MWH Soft water and wastewater modeling and management software in the Philippines and Turkey, respectively. In this role, the new channel partners will provide leading hydraulic infrastructure modeling technology and strong local support in two of the world’s most rapidly growing markets.

Geodata (www.geodata.com.ph) is an information technology company focused on providing Geographic Information System (GIS) solutions and related geospatial technologies to the Philippines market. It was founded in 1991 to meet the growing demand for digital geographic information products and services in the country. Geodata has participated in public and private efforts to better manage utilities, local governments, environment and natural resources through the use of geocentric applications and technology. “We are excited to join the global network of MWH Soft certified channel partners and help bring hydraulic modeling and management applications to the Philippines water and wastewater community,” said Frances Dayrit, Executive Vice President of GeoData.

Universal (www.uni-yaz.com) was established in Istanbul in 1990 and works with both national and local government clients in Turkey to provide advanced IT and GIS software applications. It maintains offices in Istanbul, Ankara, Izmir and has completed software projects with governments and utilities throughout Turkey. “MWH Soft water and wastewater modeling tools are the best of their kind in the world ,” said Kenan Duru, Business Development Manager at Universal. “We look forward to deploying and supporting these tools in municipalities throughout our region.”

“With the addition of Geodata and Universal, MWH Soft now has local representation in over 25 countries around the world,” noted Paul F. Boulos, Ph.D., Hon.D.WRE, F.ASCE, President and Chief Operating Officer of MWH Soft. “This global reach underscores our commitment to providing powerful, easy-to-use wet infrastructure modeling and management software as well as high touch customer support to the world’s engineers.”
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