2001
December 3, 2001.  Inverted Siphons (Depressed Sewers)
November 5, 2001.  Static Pressure - New calculation
October 15, 2001.  New Culvert Design Calculation using Inlet and Outlet Control
September 18,2001.  Culvert Design
August 7, 2001.  Parshall Flume - Submerged and free flow
July 19, 2001.  Price increase
June 8, 2001.  Open channel flow measurement
May 25, 2001.  Flume calculations and rating curves
May 8, 2001.  Flumes for open channel flow measurement
April 16, 2001.  New Calculation - Packed Bed
March 26, 2001.  Pipe Network Example
February 26, 2001.  Pipe Network Calculation
February 5, 2001.  What calculation should I use?
January 16, 2001.  Liquid or Gas Flow in Pipes with Pump Curve

LMNO Engineering, Research, and Software, Ltd.
The fluid flow calculations website: http://www.LMNOeng.com
7860 Angel Ridge Rd. Athens, Ohio 45701 USA +1(740) 592-1890
LMNO@LMNOeng.com

Inverted Siphons (Depressed Sewers)

Stormwater and wastewater sewers often encounter obstructions such as rivers, other pipes, subways, tunnels, or valleys. To pass these obstructions, a common method is for the sewer pipe to drop sharply, then run horizontal under the obstruction, and finally rise to the desired elevation. The piping going under the obstruction is traditionally called an "inverted siphon", but since the pipe is not actually acting as a siphon, a better term is "depressed sewer" (Metcalf and Eddy, 1981).

Unlike the main sewer pipe, the depressed sewer pipe(s) flow under pressure. Special care must be taken in inverted siphon design since losses are greater for pressurized flow, and the velocity in the depressed sewer must be at least 4 ft/s (1.2 m/s) for storm water or 3 ft/s (0.9 m/s) for sewage (Metcalf and Eddy, 1981). Therefore, even if there is only one main sewer pipe, several depressed pipes may be required.

We are currently completing a calculation to determine the diameters of depressed sewer pipes (inverted siphons) based on the discharge. The calculation will compute pipe diameters and velocities, as well as pipe inlet invert elevations and wall heights in the inlet chamber. If you are unfamiliar with inverted siphons, we will have diagrams on our calculation page.

Ken Edwards, Ph.D., P.E. (Owner/Engineer/Programmer)
LMNO Engineering, Research, and Software, Ltd.
http://www.LMNOeng.com

Reference:
Metcalf and Eddy, Inc. George Tchobanoglous, editor. Wastewater Engineering: Collection and Pumping of Wastewater. McGraw-Hill, Inc. 1981.

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(c) 2001 LMNO Engineering, Research, and Software, Ltd.

LMNO Engineering, Research, and Software, Ltd.
The fluid flow calculations website: http://www.LMNOeng.com
7860 Angel Ridge Rd. Athens, Ohio 45701 USA +1(740) 592-1890
LMNO@LMNOeng.com

Static Pressure - New calculation (free)
http://www.LMNOeng.com/Statics/pressure.htm

Often people ask us, "How do you convert 40 psi to feet of water?" or "How many meters are in 1 atmosphere?" We decided to write a calculation that performs these conversions.

Conversions between pressure and elevation are known as static pressure equivalences, and the equation is P=dgh; where P=pressure, d=mass density, g=gravitational acceleration, and h=elevation. Solving the equation for h allows us to determine that 92.4 ft. of water is equivalent to 40 psi. Since the density of water varies somewhat with temperature, it is important to state the temperature used for the density. I used 20C. You might have noticed that the unit conversions can be cumbersome. Our calculation takes care of the unit conversions for you.

If you are curious how many meters are in one atmosphere, compute it yourself. The calculation does not require registration. Just remember that you must decide what fluid you want to determine the meters of. One atmosphere is equivalent to more meters of oil than meters of water (because oil has a lower density).

Please see http://www.LMNOeng.com/Statics/pressure.htm to run the calculation.

Ken Edwards, Ph.D., P.E. (Owner/Engineer/Programmer)
LMNO Engineering, Research, and Software, Ltd.
http://www.LMNOeng.com

You received this free newsletter because you requested it at our website. If you no longer wish to receive it, send a message stating "Discontinue Newsletter" to LMNO@LMNOeng.com.

(c) 2001 LMNO Engineering, Research, and Software, Ltd.

LMNO Engineering, Research, and Software, Ltd.
The fluid flow calculations website: http://www.LMNOeng.com
7860 Angel Ridge Rd. Athens, Ohio 45701 USA (740) 592-1890
LMNO@LMNOeng.com

New Culvert Design Calculation using Inlet and Outlet Control
http://www.LMNOeng.com/Pipes/hds.htm

Culverts have been utilized for thousands of years as a means to transmit water under walkways and roads. Too often, culverts are selected without sufficient thought of how much water needs to be convey under extreme conditions. If a culvert cannot convey all of the incoming water, then the water will flow over or around the pipe - or simply back up behind the culvert creating a pond or reservoir. If any of these conditions are unacceptable, then the proper culvert diameter and number of culverts must be selected prior to installation in order to convey all of the anticipated water through the pipe(s).

Our new culvert design calculation aids the designer in selecting the number of culverts and culvert diameter. It also plots headwater depth vs. discharge so that the designer can view culvert performanace over a wide range of flows. Our calculation is primarily based on the methodology presented in Hydraulic Design of Highway Culverts by Normann (1985) and published by the USA Department of Transportation's Federal Highway Administration.

Please see http://www.LMNOeng.com/Pipes/hds.htm to run the calculation and to see equations, diagrams, and additional description.

Ken Edwards, Ph.D., P.E. (Owner/Engineer/Programmer)
LMNO Engineering, Research, and Software, Ltd.
http://www.LMNOeng.com

Reference:
Normann, J. M. 1985. Hydraulic design of highway culverts. HDS-5 (Hydraulic Design Series 5). FHWA-IP-85-15. NTIS publication PB86196961. Obtainable at http://www.ntis.gov.

You received this free newsletter because you requested it at our website. If you no longer wish to receive it, send a message stating "Discontinue Newsletter" to LMNO@LMNOeng.com .

(c) 2001 LMNO Engineering, Research, and Software, Ltd.

LMNO Engineering, Research, and Software, Ltd.
The fluid flow calculations website: http://www.LMNOeng.com
7860 Angel Ridge Rd. Athens, Ohio 45701 USA (740) 592-1890
LMNO@LMNOeng.com

Culvert Design

We will soon be loading a new culvert design calculation. It will aid in design and analysis of circular culverts that flow under a road or dam. The calculation uses equations for inlet control and outlet control. Inlet control means that flow through the culvert is limited by culvert entrance characteristics. Outlet control means that flow through the culvert is limited by friction between the flowing water and the culvert barrel.

Inlet control most often occurs for short, smooth, or greatly downward sloping culverts. Outlet control governs for long, rough, or slightly sloping culverts. The type of control also depends on the flowrate. For a given culvert installation, inlet control may govern for a certain range of flows while outlet control may govern for other flowrates.

The calculation also will compute headwater depth for high flowrates that exceed the capacity of the culvert(s), resulting in flow over a road or dam. It will also have a graphing feature where the user enters minimum and maximum flowrates. Then, a graph of headwater depth vs. flowrate is shown.

Since 1998, we have had a calculation for circular culvert flow using Manning's equation ( http://www.LMNOeng.com/CircularCulvert.htm ). Manning's equation is the equation most commonly used for simulating outlet control. Our new calculation will implement Manning's equation for outlet control and weir/orifice equations for inlet control.

Ken Edwards, Ph.D., P.E. (Owner/Engineer/Programmer)
LMNO Engineering, Research, and Software, Ltd.
http://www.LMNOeng.com

You received this free newsletter because you requested it at our website. If you no longer wish to receive it, send a message stating "Discontinue Newsletter" to LMNO@LMNOeng.com.

(c) 2001 LMNO Engineering, Research, and Software, Ltd.

LMNO Engineering, Research, and Software, Ltd.
The fluid flow calculations website: http://www.LMNOeng.com
7860 Angel Ridge Rd. Athens, Ohio 45701 USA (740) 592-1890
LMNO@LMNOeng.com

Before founding LMNO Engineering in 1998, I taught fluid mechanics to third year civil and mechanical engineering students at Ohio University (USA). The concept of "head loss" always seemed to be difficult for students to understand.

Head loss is part of the energy equation. One of our first (and free) calculation pages, http://www.LMNOeng.com/energy.htm, shows the energy equation in one of its simpler forms. The equation is valid for flow in pressure pipes as well as open channels. Head loss is the sum of energy in the fluid at an upstream location minus the sum of energy at a downstream location. Energy consists of elevation, pressure, and velocity. Head loss has a positive value.

Introductory courses in fluid mechanics often begin with a discussion of inviscid fluids. An inviscid fluid has no viscosity. No such fluid exists in reality, but the concept is useful as a first step in explaining the Bernoulli and energy equations. An inviscid fluid has no head losses; upstream energy minus downstream energy equals zero. Head losses arise from fluid viscosity and the friction it causes between the moving fluid and the stationary pipe (or channel) walls.

Ken Edwards, Ph.D., P.E. (Owner/Engineer/Programmer)
LMNO Engineering, Research, and Software, Ltd.
http://www.LMNOeng.com

You received this free newsletter because you requested it at our website. If you no longer wish to receive it, send a message stating "Discontinue Newsletter" to LMNO@LMNOeng.com.

(c) 2001 LMNO Engineering, Research, and Software, Ltd.

LMNO Engineering, Research, and Software, Ltd.
The fluid flow calculations website: http://www.LMNOeng.com
7860 Angel Ridge Rd. Athens, Ohio 45701 USA (740) 592-1890
LMNO@LMNOeng.com

Parshall Flume - Submerged and Free Flow
http://www.LMNOeng.com/Flumes/parshall.htm

LMNO Engineering's newest flume calculation computes discharge and rating curves for free flowing or submerged Parshall flumes. A free flowing flume can be identified by the drop in water depth at the flume throat. In submerged flow, the downstream water backs up into the throat swallowing the drop - making the drop difficult or impossible to identify. Analysis of submerged flow requires two head measurements - one in the approach channel and one in the throat; whereas, free flow requires only the upstream head measurement. Our Parshall flume calculation is based on the ISO 9826 (1992) standard.

Graphs of discharge versus head and discharge versus submergence ratio can be prepared on the web page. You can see that increasing the submergence ratio causes the discharge to decrease for a constant approach head. (Submergence ratio is defined as throat head divided by approach head.) The Parshall flume equations and methodology are described on the web page.

Our other flume calculation ( http://www.LMNOeng.com/Flumes/flumes.htm ) analyzes free flowing trapezoidal, rectangular, U-shape, and Parshall flumes. Both parshall.htm and flumes.htm use identical equations for free flowing Parshall flumes.

Ken Edwards, Ph.D., P.E. (Owner/Engineer/Programmer)
LMNO Engineering, Research, and Software, Ltd.
http://www.LMNOeng.com

Reference:
International Organization of Standards (ISO 9826). 1992. Measurement of liquid flow in open channels - Parshall and SANIIRI flumes. Reference number: ISO 9826:1992(E).

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(c) 2001 LMNO Engineering, Research, and Software, Ltd.

LMNO Engineering, Research, and Software, Ltd.
The fluid flow calculations website: http://www.LMNOeng.com
7860 Angel Ridge Rd. Athens, Ohio 45701 USA (740) 592-1890
LMNO@LMNOeng.com

Price increase

We anticipate raising the rates for our password-protected calculations, and wanted to give advance notice to our newsletter readers - in case you wish to register at the current rates. Currently, we charge \$20 (US Dollars) for 7 days' access to the password-protected calculations. We anticipate raising this to \$30. For a 1 year registration, our current fee is \$100, and we anticipate raising this to \$300 [actually changed to \$200 instead of \$300- KE, Aug 2001]. We will also be changing our 6 month rate, which is currently \$70.

If you wish to register at the current rates, please register within the next few days since the rates will be increasing in the next few weeks. Our registration page is http://www.LMNOeng.com/register.htm .

We are continually developing new calculations for the website, and appreciate your past and future suggestions.

Regards,
Ken Edwards, Ph.D., P.E. (Owner/Engineer/Programmer)
LMNO Engineering, Research, and Software, Ltd.
http://www.LMNOeng.com

You received this free newsletter because you requested it at our website. If you no longer wish to receive it, send a message stating "Discontinue Newsletter" to LMNO@LMNOeng.com.

(c) 2001 LMNO Engineering, Research, and Software, Ltd.

LMNO Engineering, Research, and Software, Ltd.
The fluid flow calculations website: http://www.LMNOeng.com
7860 Angel Ridge Rd. Athens, Ohio 45701 USA (740) 592-1890
LMNO@LMNOeng.com

Open channel flow measurement

We offer calculations for three commonly used methods for open channel flow measurement - weirs, flumes, and end depth. The end depth method is the simplest because a structure does not need to be built - water drops freely from the downstream end of a culvert or channel. All that is needed are the dimensions of the culvert or channel and the water depth. Freely discharging culverts are widely used as discharge structures, and a picture of one is shown at http://www.LMNOeng.com/Waterfall/CulvertDischarge.htm.

Weirs are used for flow measurement when large head losses are acceptable and free discharge can be accommodated. Weirs are relatively inexpensive to construct, install, and operate. However, weirs will back up the flow since they are obstructions across the channel width and cause low velocities upstream of the weir. Sediment will build up behind the weir. A simple triangular (or V-notch) weir is shown at http://www.LMNOeng.com/Weirs/vweir.htm.

Flumes have been the topic of our last two newsletters. They are more expensive than weirs but have the advantage of much less head loss. They are flow-through devices that do not cause the water to back up like weirs do. There are various types of flumes which are designed to allow varying ranges of discharge through them while minimizing sediment build-up and head loss. A flume photograph can be found at http://www.LMNOeng.com/Flumes/flumes.htm.

Thank you for your interest in the LMNO Engineering website,
Ken Edwards, Ph.D., P.E. (Owner/Engineer/Programmer)
LMNO Engineering, Research, and Software, Ltd.
http://www.LMNOeng.com

You received this free newsletter because you requested it at our website. If you no longer wish to receive it, send a message stating "Discontinue Newsletter" to LMNO@LMNOeng.com.

(c) 2001 LMNO Engineering, Research, and Software, Ltd.

LMNO Engineering, Research, and Software, Ltd.
The fluid flow calculations website: http://www.LMNOeng.com
7860 Angel Ridge Rd. Athens, Ohio 45701 USA (740) 592-1890
LMNO@LMNOeng.com

Flume calculations and rating curves
http://www.LMNOeng.com/Flumes/flumes.htm

Our first graphing calculator is now on-line. It has our usual calculation format plus a graph below the calculation for plots of flowrate versus water depth (head).

In the calculation, flowrate can be computed for four different types of flumes - Parshall, trapezoidal, rectangular, and U shaped. Flumes, like weirs, require a water depth measurement. Then, equations or tables are used to obtain discharge. Flumes are mathematically more complicated to analyze than weirs and have more complicated construction; however, they offer less energy loss and can pass sediment much more readily than weirs.

Flumes have been studied for many decades. The International Organization of Standardization (ISO) has published complex methodologies relating flume discharge to water depth. The methodology is suited to a computer since it is not a simple algebraic equation. Discharge and rating curves can be obtained with a click of your mouse button on our flumes page, but we also present the ISO methodology so that the calculation is not simply a "black box."

Thank you for your interest in the LMNO Engineering website,
Ken Edwards, Ph.D., P.E. (Owner/Engineer/Programmer)
LMNO Engineering, Research, and Software, Ltd.
http://www.LMNOeng.com

You received this free newsletter because you requested it at our website. If you no longer wish to receive it, send a message stating "Discontinue Newsletter" to LMNO@LMNOeng.com.

(c) 2001 LMNO Engineering, Research, and Software, Ltd.

LMNO Engineering, Research, and Software, Ltd.
The fluid flow calculations website: http://www.LMNOeng.com
7860 Angel Ridge Rd. Athens, Ohio 45701 USA (740) 592-1890
LMNO@LMNOeng.com

Flumes for open channel flow measurement

Flumes, as used in this newsletter, refer to open channel flow measuring devices. Within the next few weeks, we will have a new calculation on our website for four different flume types - Parshall, Rectangular, Trapezoidal, and U-shaped.

Flumes are available in various widths. Usually, the maximum expected depth is fixed by the channel characteristics where the flume is installed, and in no case should exceed 2 m.

Flumes are designed to force a transition from sub-critical to super-critical flow. Such a transition causes flow to pass through critical depth at the flume throat. At the critical depth, energy is minimized and there is a direct relationship between water depth and velocity (and flowrate). However, it is physically very difficult to measure critical depth in a flume because its exact location is difficult to determine and may vary with flowrate. Through mass conservation, the upstream depth is related to the critical depth. Therefore, flowrate can be determined by measuring the upstream depth, which is a highly reliable measurement.

Our flume calculators will be based on ASTM and ISO standards for flumes. These standards were developed from theoretical relationships and modified by experimental observations.

Thank you for your interest in the LMNO Engineering website,
Ken Edwards, Ph.D., P.E. (Owner/Engineer/Programmer)
LMNO Engineering, Research, and Software, Ltd.
http://www.LMNOeng.com

ASTM is American Society for Testing and Materials.
ISO is International Standards Organization.

You received this free newsletter because you requested it at our website. If you no longer wish to receive it, send a message stating "Discontinue Newsletter" to LMNO@LMNOeng.com.

(c) 2001 LMNO Engineering, Research, and Software, Ltd.

LMNO Engineering, Research, and Software, Ltd.
The fluid flow calculations website: http://www.LMNOeng.com
7860 Angel Ridge Rd. Athens, OH 45701 USA (740) 592-1890
LMNO@LMNOeng.com

New Calculation - Packed Bed
http://www.LMNOeng.com/Groundwater/PackedBed.htm

Chemical engineers know this as a packed or porous bed. Groundwater hydrologists call this a permeameter or flow through porous media. It is a column containing particles that any fluid can be flowing through. The column can be of any orientation (upflow, downflow, sideways flow). The calculation can compute flowrate and velocity through the column, or pressure loss, or column length.

We provide two computation methods - Idelchik method and Darcy's law. Hydrogeologists and civil engineers are usually more familiar with Darcy's law while chemical and mechanical engineers may be more familiar with the Idelchik approach. The Idelchik method is valid for laminar or turbulent flow while Darcy's law is valid only for laminar flow. Darcy's law requires entering the permeability while Idelchik relies only on particle size and porosity. If the Idelchik method is selected, permeability will be back-calculated (based on Darcy's law) in case one wishes to compare a bed material with a soil type.

The calculation also computes a minor loss coefficient for flow through the bed in case the bed is part of a longer pipeline that you are modeling. Any liquid or gas can be used with either method so long as the fluid's density and viscosity are known. Several fluids (e.g. water, gasoline, oil, air, nitrogen, mercury, etc.) have properties built into the program. The calculation works in demonstration mode for Mercury as the fluid.

Thank you for your interest in the LMNO Engineering website,
Ken Edwards, Ph.D., P.E. (Owner/Engineer/Programmer)
LMNO Engineering, Research, and Software, Ltd.
http://www.LMNOeng.com

References
Darcy's law: Freeze, R. A. and J. A. Cherry. 1979. Groundwater. Prentice Hall, Inc.
Idelchik method: Fried, E. and I. E. Idelchik. 1989. Flow Resistance: A Design Guide for Engineers. Hemisphere Pub. Corp.

You received this free newsletter because you requested it at our website. If you no longer wish to receive it, send a message stating "Discontinue Newsletter" to LMNO@LMNOeng.com.

(c) 2001 LMNO Engineering, Research, and Software, Ltd.

LMNO Engineering, Research, and Software, Ltd.
The fluid flow calculations website: http://www.LMNOeng.com
7860 Angel Ridge Rd. Athens, OH 45701 USA (740) 592-1890
LMNO@LMNOeng.com

Pipe Network Example
http://www.LMNOeng.com/Pipes/PipeNetwork.htm

I will present an example of how to determine the height of a city water tower using our Pipe Network calculation. Fluid: water at 20C. Pipe material: ductile iron (cast iron). Flow in gpd (gallons (US)/day), Elevations in ft, Diameters in inch, Pressure in psi, Head loss in psi, Lengths in ft, Z+P/S in ft. The water tower will be at node D.

In this example, the water tower is placed on a hill. The hill elevation is 50 ft. above all of the other nodes. All other nodes have the same elevation. All pipes are 10 inch inside diameter and 1000 ft. long. Each outfow node represents a collection of businesses or houses. For simplicity, let's say the required flows out of nodes A-C and E-I is 500,000 gpd each and the pressure requirement is 100 psi at each node. Therefore, set the pressure at the furthest node from the water tower to 100 psi to guarantee that all nodes will have at least 100 psi pressure. The node furthest from the water tower will be C or I (both are the same distance from node D since all pipes have the same length). I'll use node I.

Summary of inputs: Select "P known at node I". Enter Q node for nodes A-C and E-I as -5e5 gpd (be sure to use the negative sign since these are withdrawals). Enter Q node for node D as 4e6 gpd (this number is positive since it is the inflow to the system. I got 4e6 from 5e5 x 8 nodes). Enter the elevation of node D as 50 ft and all other node elevations as 0.0 ft. Enter the pressure at node I as 100 psi. Enter the diameter of each pipe as 10 inches and the length of each pipe as 1000 ft.

After making the proper data entries, click the "Calculate" button and look at the results. All node pressures A-C and E-I are at least 100 psi as required. Look at the node D results: the water tower required height is 238.71964 ft - 50 ft = 189 ft. (rounding to the nearest ft). The pressure of 81.7 psi is at the base of the tank (at an elevation of 50 ft). The pipe "H,V,Re pipe" fields are scrollable with your arrow keys, so you can see the head loss, velocity, and Reynolds number for each pipe. You can see the flowrate in each pipe and the direction of flow from the arrows. You might try reducing the diameters for pipes 5 and 10 to save money since they don't carry much flow.

A copy of this example is viewable at http://www.LMNOeng.com/Pipes/example3(4).htm. Note that the "H,V,Re pipe" field is not scrollable in the gif file.

I hope this example has been helpful,
Ken Edwards, Ph.D., P.E. (Owner/Engineer/Programmer)
LMNO Engineering, Research, and Software, Ltd.
http://www.LMNOeng.com

You received this free newsletter because you requested it at our website. If you no longer wish to receive it, send a message stating "Discontinue Newsletter" to LMNO@LMNOeng.com .

(c) 2001 LMNO Engineering, Research, and Software, Ltd.

LMNO Engineering, Research, and Software, Ltd.
The fluid flow calculations website: http://www.LMNOeng.com
7860 Angel Ridge Rd. Athens, OH 45701 USA (740) 592-1890
LMNO@LMNOeng.com

Pipe Network Calculation
http://www.LMNOeng.com/Pipes/PipeNetwork.htm

Many of you asked for a pipe network calculation - it is now completed and on-line. It allows up to 12 pipes and 9 nodes. You can simulate a system that has many series and parallel pipes or you can model a single pipeline (or manifold) that has up to 12 pipes of different diameters and lengths in series with inflows or outflows at the nodes (junctions) between the pipes. You do not have to use all the pipes or nodes.

The program can simulate flow of any liquid or gas through the pipes. The Darcy-Weisbach (Moody diagram method) or Hazen-Williams method may be selected for losses. After entering pipe diameters, lengths, node elevations, node inflows, node outflows, and pressure at a single node, the program computes flowrate, loss, velocity, and Reynolds number for each pipe and the pressure and hydraulic head at all existing nodes.

The calculation has a demonstration mode, so it will run even if you are not a registered user. The demonstration mode allows all pipes and nodes but only works for mercury flowing through wood pipes with SI (metric) units.

Experiment with PipeNetwork. If you would like to purchase it for stand-alone use to run from your hard disk without an internet connection, the cost is \$150 (US Dollars). To use all features on-line, the cost is just \$20/week or \$100/year; the on-line fee enables all calculations (not just PipeNetwork).

Enjoy the site! Fluid flow is an exciting and challenging field!

Sincerely,
Ken Edwards, Ph.D., P.E. (Owner/Engineer/Programmer)
http://www.LMNOeng.com

You received this free newsletter because you requested it at our website. If you no longer wish to receive it, send a message stating "Discontinue Newsletter" to LMNO@LMNOeng.com.

(c) 2001 LMNO Engineering, Research, and Software, Ltd.

LMNO Engineering, Research, and Software, Ltd.
The fluid flow calculations website: http://www.LMNOeng.com
7860 Angel Ridge Rd. Athens, OH 45701 USA (740) 592-1890
LMNO@LMNOeng.com

What calculation should I use? Have you ever visited our site for a specialized calculation and didn't see it listed?

Need the flowrate through a pinhole in a leaky pipe? Try our Bernoulli calculator: http://www.LMNOeng.com/Flow/bernoulli.htm.

Need to know if a pump is required to carry water through your pipe? Try our Darcy-Weisbach or Hazen-Williams calculations without pump curve. Solve for pump head. If a pump is required, pump head will be positive. http://www.LMNOeng.com/DarcyWeisbach.htm or http://www.LMNOeng.com/HazenWilliamsDesign.htm.

Need to know if a blower is required to carry air through your pipe? Try our Darcy-Weisbach calculation without pump curve: http://www.LMNOeng.com/DarcyWeisbach.htm. Solve for pump head like above. Note that you can't use Hazen-Williams for air since Hazen-Williams is only valid for water.

Need to know the flowrate through a pipe with a pump already installed? Try Darcy-Weisbach with pump curve (any liquid or gas) or Hazen-Williams with pump curve (water only): http://www.LMNOeng.com/Pipes/DWpump.htm or http://www.LMNOeng.com/Pipes/HWpump.htm.

Need to know pressure change in a pipe due to an expansion or contraction? Try our Bernoulli calculator: http://www.LMNOeng.com/Flow/bernoulli.htm.

Need a Moody friction factor? Try our Moody friction factor calculation: http://www.LMNOeng.com/moody.htm.

Need to determine velocity using a pitot tube? Try our Bernoulli calculation: http://www.LMNOeng.com/Flow/bernoulli.htm.
Need to determine discharge over a dam but our rectangular weir calculation gives "parameter out of range" messages? Try our Bernoulli calculation - not as accurate but no limits on the variables: http://www.LMNOeng.com/Flow/bernoulli.htm.

Need the flowrate through an orifice plate, but our orifice calculation gives you a "parameter out of range" message? Try our Bernoulli calculator - not as accurate but no limits on the variables: http://www.LMNOeng.com/Flow/bernoulli.htm.

Need to know pond storage volume required to attenuate a flood? Try our Detention basin storage calculation: http://www.LMNOeng.com/Hydrology/storage.htm.

Need to analyze a network of pipes? By the time our next newsletter is published, we expect to have a pipe network calculation on the website. It will be able to handle up to 12 pipes with 9 inflow (or outflow) nodes. You will have a choice of Darcy-Weisbach or Hazen-Williams for the friction losses.

Have another question? Send me an e-mail ( LMNO@LMNOeng.com) or give me a call (USA: 740/592-1890).

Ken Edwards, Ph.D., P.E. (Owner/Engineer/Programmer)
LMNO Engineering, Research, and Software, Ltd.

You received this free newsletter because you requested it at our website. If you no longer wish to receive it, send a message stating "Discontinue Newsletter" to LMNO@LMNOeng.com.

(c) 2001 LMNO Engineering, Research, and Software, Ltd.

LMNO Engineering, Research, and Software, Ltd.
The fluid flow calculations website: http://www.LMNOeng.com
7860 Angel Ridge Rd. Athens, Ohio  45701 USA (740) 592-1890
LMNO@LMNOeng.com

Liquid or Gas Flow in Pipes with Pump Curve
http://www.LMNOeng.com/Pipes/DWpump.htm

In our newsletter of October 31, 2000, we introduced a calculation for water flow in pipes using the Hazen-Williams equation with a pump curve. We have now completed a similar program except it can handle any liquid or gas.

The new program uses the Darcy-Weisbach equation for friction losses (major losses) and also allows minor losses (valves, pipe bends, etc.). The calculation automatically intersects a system curve with a pump curve to tell you the operating point (flowrate and total dynamic head). Alternatively, if you know the flowrate or velocity, you can solve for diameter, pipe length, pressure difference, elevation difference, or the sum of the minor loss coefficients.

To keep the input data relatively simple, we only require you to enter two points on the pump curve - flow at zero head and head at zero flow. A parabolic curve is then formed between the two points. All equations and methodology are described on the web page http://www.LMNOeng.com/Pipes/DWpump.htm.

Thank you for your interest in the LMNO Engineering website, http://www.LMNOeng.com
Newsletter written by Ken Edwards, Ph.D., P.E. (Owner/Engineer/Programmer)

You received this free newsletter because you requested it at our website. If you no longer wish to receive it, send a message stating "Discontinue Newsletter" to LMNO@LMNOeng.com.

(c) 2001 LMNO Engineering, Research, and Software, Ltd.