3 Pipe Flow
Michelle Benitone
The Pipe Flow Expert Software can be used to model pipe systems with just a few pipes through to more complex systems with many hundreds of pipes. Find out how the Pipe Flow Expert Piping Design Software can help you (just like it helps other professional engineers in over 100 countries worldwide).
The Pipe Flow Wizard Software Calculator can be used to find flow rate, pressure drop, pipe size, or pipe length, based on a single pipe calculation. Find out how the Pipe Flow Wizard Single Pipe Calculator can help you perform calculations on a single length of pipe, saving you time & effort, and improving the reliability of your calculated results.
The Pipe Flow Advisor Software can be used to calculate flow rates in open channels, work out tank empty times, and find volume of different shapes. Find out how the Pipe Flow Advisor Software for Channel & Tanks can help you with your channel, tank, and volume calculations.
In fluid mechanics, pipe flow is a type of fluid flow within a closed conduit, such as a pipe, duct or tube. It is also called as Internal flow.[1] The other type of flow within a conduit is open channel flow. These two types of flow are similar in many ways, but differ in one important aspect. Pipe flow does not have a free surface which is found in open-channel flow. Pipe flow, being confined within closed conduit, does not exert direct atmospheric pressure, but does exert hydraulic pressure on the conduit.
Not all flow within a closed conduit is considered pipe flow. Storm sewers are closed conduits but usually maintain a free surface and therefore are considered open-channel flow. The exception to this is when a storm sewer operates at full capacity, and then can become pipe flow.
Energy in pipe flow is expressed as head and is defined by the Bernoulli equation. In order to conceptualize head along the course of flow within a pipe, diagrams often contain a hydraulic grade line (HGL). Pipe flow is subject to frictional losses as defined by the Darcy-Weisbach formula.
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A family of three-dimensional traveling waves for flow through a pipe of circular cross section is identified. The traveling waves are dominated by pairs of downstream vortices and streaks. They originate in saddle-node bifurcations at Reynolds numbers as low as 1250. All states are immediately unstable. Their dynamical significance is that they provide a skeleton for the formation of a chaotic saddle that can explain the intermittent transition to turbulence and the sensitive dependence on initial conditions in this shear flow.
There are times when pipes are installed in an adverse slope condition. A couple examples I can think of are if the pipes are in a siphon, the ground settles, or installed incorrectly. I like the idea of having the options.
I do agree with your points. I like how you prefaced it with "there are times". I would guess if the default was by slope, I would change 1 pipe slope out of 1000 to Start to End structure. I have used it for siphon design, the others seem to be field condition tasks. It is interesting having new users figure out the pipe structure to structure direction, then the downslope/upslope layout method, only to see the flow direction is opposite due to one of the options you can choose.
Under toolspace - prospector - pipe networks open your pipe network. Click on pipes so that the pipe spreadsheet appears at the bottom of the toolspace. Find the "flow method" column in the spreadsheet and right click on the "flow method" header at the top of the column. Select edit and select "by slope." All pipes in the network will change to "by slope" (or whatever flow method you choose).
You can also use this operation to change the description of all your pipes as well. By default, the pipe description is drawn from the parts catalog, which cannot be edited in the catalog. After you have laid out your pipe network (a SS network for example), you can change all the pipe descriptions to PVC, C-900, DIP, etc by right clicking on the "description" header and entering a new string. The same works for changing all the structure descriptions too.
Agreed here we are 5 years later still no found fix. I checked where it should be in the COMMANDS editor to adjust DEFAULTS. Create it in COMMANDS; CREATE NETWORK ; PIPE NETWORK DEFAULTS; OR please guide me to the right spot if I and missing it. Thank you!
It doesn't appear to be an option to change the default. Make this adjustable or only set by default to be by slope, then people can adjust it to be something else in the rare case that it's needed. We add flow arrows labels to our pipes to show the direction of flow, and it needs to be set by slope to display correctly.
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Turbulence is the major cause of friction losses in transport processes and it is responsible for a drastic drag increase in flows over bounding surfaces. While much effort is invested into developing ways to control and reduce turbulence intensities1,2,3, so far no methods exist to altogether eliminate turbulence if velocities are sufficiently large. We demonstrate for pipe flow that appropriate distortions to the velocity profile lead to a complete collapse of turbulence and subsequently friction losses are reduced by as much as 90%. Counterintuitively, the return to laminar motion is accomplished by initially increasing turbulence intensities or by transiently amplifying wall shear. Since neither the Reynolds number nor the shear stresses decrease (the latter often increase), these measures are not indicative of turbulence collapse. Instead, an amplification mechanism4,5 measuring the interaction between eddies and the mean shear is found to set a threshold below which turbulence is suppressed beyond recovery.
This HandHeld portable unit from Pulsar Measurement is designed for use with the FlowPulse pipe flow sensor, providing portable pipe flow monitoring and offering a toolset that allows programming of the non-contacting pipe flow sensor, monitoring, and data acquisition. The HandHeld controller connects to the pre-installed FlowPulse sensor or can operate as a self-contained kit, giving instant feedback on pipe flow via its color screen.
The FlowPulse HandHeld controller is available as a stand-alone unit to use with existing FlowPulse sensors or can be purchased as a complete kit with a convenient carry case. The portable non-contacting, clamp-on, pipe flow monitoring system allows the operator to view traces and recorded data files - as well as loading and saving parameter files.
Use the portable pipe flow monitoring system to complete system checks, monitor asset performance, or validate inline flow meter readings. Suitable for pump performance monitoring, industrial flow, irrigation flow, food and beverage manufacturers, pharmaceutical manufacturers, and much more!
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Flows through pipes and channels are, in practice, almost always turbulent, and the multiscale eddying motion is responsible for a major part of the encountered friction losses and pumping costs1. Conversely, for pulsatile flows, in particular for aortic blood flow, turbulence levels remain low despite relatively large peak velocities. For aortic blood flow, high turbulence levels are intolerable as they would damage the shear-sensitive endothelial cell layer2-5. Here we show that turbulence in ordinary pipe flow is diminished if the flow is driven in a pulsatile mode that incorporates all the key features of the cardiac waveform. At Reynolds numbers comparable to those of aortic blood flow, turbulence is largely inhibited, whereas at much higher speeds, the turbulent drag is reduced by more than 25%. This specific operation mode is more efficient when compared with steady driving, which is the present situation for virtually all fluid transport processes ranging from heating circuits to water, gas and oil pipelines.
Our clients, large and small, understand how the power of pipe flow technology can transform the way they do business. Since 1967, we have collaborated with Canada's resource industries on a range of ground-breaking pipeline and fluid mechanics applications. A few examples are:
I did avery quick run based on your setup and got a value of 162kpa which is very close to the theoretical value. I ran 2D axisymmetric with SST k-w. The maximum y+ was around 10. I am wondering if there is some issue with your setup. Can you share more details? Can you perhaps try a 2D axisymmetric run?
I believe I understand what may be going on. What was the wall-function you used when solving with standard k-epsilon? The standard wall-functions deteriorate for y+ less than 30. In your case, you should be using wall functions that are tailored for low y+ values. SST k-w is y+ insensitive and hence is able to correctly predict the solution. Can you try k-epsilon using Enhanced Wall Treatment (EWT) and check the pressure drop?
It's very interesting since the pipe flow is such a simple case. Many people told me k-epsilon should be OK for most of the problems in simple geometries and normal Reynolds number range. Apparently I should be more careful about using it.
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