Pipe flow, a branch of hydraulics and fluid mechanics, is a type of liquid flow within a closed conduit (conduit in the sense of a means of containment). 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.
Pump is supply fluid to the 35 nozzles through 3 inch pipe and manifold.At nozzle the pressure is 32 m and pressure at pump outlet is 30 m .The flow rate required at nozzles is 500 lpm. Pump can deliver 860 lpm at 24 m head.pump size 100x100 mm
1)how delivary pipe size affects the pressure head...
Hello!
I have a question regarding the application of the bernoulli equation and calculation of the flow through a parallel pipe branch. It's more the basic understanding how the flow will establish.
You can find a sketch attached to follow my explanation.
Let's assume I have a pipe with...
Hi guys, I am confused about the heat transfer mode of between two contacting material, especially in a channel flow.
Obviously, conduction or convection dominate the heat transfer process in the process with low object temperature .
But I am not sure if I have a fluid of 500 Kelvin, flowing...
Problem Statement: An oil with density 900 kg/m3 and viscosity 0.18 Ns/m2 flows through a circular pipe which inclines upwards
at 40° to the horizontal. The length of the pipe is 10 m and the diameter is 6 cm. The fluid pressure at the
lower end of the pipe is 350 kPa and the pressure at the...
Hello,
I want to size my system to be able to get rid of fluids without any head buildup within the container. I am just a bit confused as to what formula I should use. My problem is summed up in the following schematic. Note that P1>P2, I have assumed H=10^(-4)m and my flow rate is 0.1 m3/s...
Homework Statement
Consider a plug flow (slippery walls) with a uniform velocity ##U## in a circular pipe of diameter,##d## and length ##L##. The fluid is a supersaturated solution with a concentration ##c##. At the pipe wall, precipitation of solute happens at a net reaction rate per unit area...
Hello all,
I have been having some problems and would appreciate any help:
I have a length of insulated pipe filled with engine oil at rest, the variables are as follows:
Toil: 40 oC
Tair: 5 oC
h1 (LO): 3600.63 W/m2/K
r1 (pipe inner): 0.1 m
r2 (pipe outer): 0.1095 m
r3...
Hi everyone. Let me give a little bit of background on the problem I need help understanding.
I want to plumb an aquarium that has a sump and move the water from the sump to the main aquarium using a pump and 1" PVC pipe. The total system pipe length is going to be roughly 10 feet total with...
Hello,
I am doing a relatively simple problem, but i can't initialise it.
I have hot water at 400K moving inside a copper pipe at 300K. I would like to see the time it takes for the copper pipe's temperature to increase to 400. However I can't seem to initialise the temperature of the pipe...
Stupid question:
I have the following pipe configuration:
Working fluid = ambient air
Pipe1 = 6 inch ID x 24 inch length
Expansion1 = 2 inch length
Pipe2 = 8 inch ID x 2 inch length
Fan1 = assume 200 CFM @ 2860 rpm, 0.05 inH2O
Contraction1 = 2 inch length
Pipe3 = 6 inch ID x 12 inch length...
I have a pump running at 400rpm with 8" inlet and outlet with head 30 ft 500 gpm. Now I am planning to reduce the discharge line to 6" . Assuming the flow rate and speed constant the velocity in the pipe will increase. How do I calculate the change in head?
I used to have a slide chart that gave gpm through a level section of pipe (1/2" - 6") by measuring how long the exit stream was when it had dropped 4". Imagine a framing square with the blade on the pipe and the tongue hanging down in the stream. Slide the square out until the stream is...
http://tinypic.com/view.php?pic=mhvarc&s=9#.WD__u_mLTIU Hey guys,
So, I've got this problem, attached.
I've used Bernoulli's to produce P1 + (1/2)p(u1)^2 +P2 + (1/2)p(u2)^2 = P3+ (1/2)p(u3)^2 +P4 + (1/2)p(u4)^2 +P5 + (1/2)p(u5)^2,
Plugging in the values you get 82500 + P2 + 500(u2)^2 = P3 +...
If I a pump with a main suction header and 4 smaller branch connections of difference sizes. Let's say for this example we have (2) 3", (1) 1", and (1) 2". Also let's say our pump is requiring 20 gal/min.
The flow rate of each branch would be proportional to the area of the pipe correct? flow =...
Hey guys, I am doing an internship and I have had some thoughts about fluid flow that have come up and I am having trouble fully grasping some concepts due to no one being able to thoroughly explain any answer that they might come up with.
So I have a crude understanding of some fluid dynamics...
I have a DIY project for a lawn sprinkler system but my flow rate is insufficient : if my setup is to work properly, the sprinkler manufacturer suggests a flow rate of 2880 litres per hour at a pressure no less than 2 psi.
I measured the flow rate of my current garden faucet, which is connected...
There is an equation which perplexes me and it is about calculation of average velocity in a pipe but over area.
In the image, the velocity is already function of diameter, i.e, u=u(r) so how can we think velocity as a function of area?
Source: Fluid Mechanics, Fundamentals and...
I'm working in an engineering internship after my first year and we haven't covered fluid dynamics in my program yet. I've been assigned to find flow rates and velocities in several branches of a suction (dust collection) system in our factory. The main branch has a diameter of 30" and is...
< Mentor Note -- thread moved to HH from the technical engineering forums, so no HH Template is shown >
Pics are attached, my concerns are with question 4 and 5.
For q4
-which way is flow? How do we know?
-the working then goes on to say that energy loss is compensated by increasing in...
Hello. I'm new to the forums. I apologize if I have posted this in the wrong topic area.
I'm new to this hydrodynamics area and I'm trying to learn the concepts of boundary layer thicknesses. My question is about laminar pipe flow and calculating displacement and momentum thicknesses. I was...
Homework Statement
As shown in the figure, if the pipe net work is shifted bodily by 10m vertically up the tank, and all the other conditions remain the same as the previous figure. Will the volume flow rate change?
Or I rephrase it as, in the calculation of elevation head of pipe flow, is the...
Hi there,
I have a double-barreled question for you all. So I have two pipes connected to each other. The first pipe is 0.64cm and has a Re = 5000, the second pipe is 4.5cm and has a Re = 700. The two are connected so that the gas expands from the the first pipe to the second.
Now, I wish to...
I have some confusion about how blockages result in the laminar/turbulent flow of fluids in pipes.
From my understanding, there is a certain diameter of a blockage in a pipe that will cause the flow to transition from laminar to turbulent (depending on the velocity of flow, etc.)
What is the...
Hey Guys!
This is my first post so I apologize beforehand if there are any mistakes with my post :D
But my question is...
I have 2 water pipes that are connected to one pipe in the middle, but the distance from the 2 water pipes to the connection point are not necessarily the same. The...
Homework Statement
A water injection line is made from smooth capillary tubing with inside
diameter D = 25.0 mm . If the length of the pipe is 0.75 m and assuming
laminar flow is present up to Re = 2000, find
(i) the maximum average velocity at which the flow is laminar
(ii) the pressure...
Homework Statement
On a horizontal pipe with flowing water on point 1 there is a vertical pipe with water up to some point. On another point 2, we have a pitot tube (L shaped) against the water flow and the lever on the vertical part is higher that on point 1. If the water flow stops what...
Homework Statement
I have a tutorial question I have been struggling with. The problem is:
The ﬂow through a closed, circular sectioned pipe may be metered by measuring the speed of
rotation of a propeller having its axis along the pipe central line. Derive a relation between
the volume...
a newbie here so not sure if this is in the right place!
i'm in the middle of a paper that I'm doing for college, investigating the effects of roughness on air flow.
i set up 2 pipes, 1 rough and 1 smooth (800mm long, 36mm diameter), in a wind tunnel, measured the velocity of the air entering...
In the diagram attached I have a pipe (standard concrete) that is going from point A (Entrance) to point B (Exit). Standard water is the fluid within the pipe. Point A (entrance) has a constant uninterrupted supply of water at a velocity of 0.7m/s, how do I find the correct velocity at point B...
Homework Statement
This is in the pipe flow section and the solution treats this question like a pipe. Here is the solution:
As you can see I circled the pipe flow equations in red. If this is the case shouldn't there be frictional head loss, hf, caused by the walls of the tank? I...
1. Water at T1=240 C and P1=16 MPa is at 2 km depth. A drilling hole with diameter 0.2 m has the water flowing up with mass flow rate at 2 kg/s. The hole is considered adiabatic(no heat transfer).
I need to find the following values at the top of the hole:
Enthalpy(h), temperature(T2)...
Hi
I cannot find an equation for a boundary layer in a pipe flow (laminar). I am looking for an equivalent of the equation δ(x)=4.91x/(√Re) that works for a flow between plates (x is the distance downstream). The thing is- I am looking for BL thickness for still undeveloped flow. I would be...
Homework Statement
Water pumped to a cooling plant through a 4km long cast iron pipeline.
power available is 30kW.
what pipe diameter is required to ensure a mass flow rate of 100kg/s.
Homework Equations
The Attempt at a Solution
I know you have to guess a value and find it...
I am trying to do a pipe flow question but I am having trouble understanding how they have calculated the k values.
Example question 1.1 attached & appendix A1 attached.
We have to use appendix A1 to find the k values. I have tried using interpolation to get the k values from the example...
I am trying to predict pressure drop in a pipeline with a range of different materials.
I have used a surface profilometer to measure the surface roughness of the different materials and I have values for various surface roughness variables - Ra Rz Rmax Rq Rm S Sm R3z Wt and a range of other...
Hello,
I am stuck on a pipe flow measurement problem and I would love if some excellent minds would help me out.
I have a robot that sprays paint, and there is a motor pump providing the paint to it. I need to be able to measure the flow rate (velocity) of the paint going through the nozzle...
Homework Statement
In [1], problem 2.3 (ii), we are asked to show that for a pipe with circular cross section r = a and constant pressure gradient P = -dp/dz one has
u_z = \frac{P}{4 \mu}\left( a^2 - r^2 \right)
u_r = 0
u_\theta = 0
References:
[1] D.J. Acheson. <em>Elementary fluid...
Hey guys, i want to ask about what the effect of inserting obstacle to the velocity profile of a pipe? I mean when i insert a cube obstacle inside a pipe, how the velocity profile look like? let's say the velocity profile is in laminar flow. Thanks
Hi
As fluid enters a pipe and progresses further down, does the shear stress at the wall reduce whilst the boundary layer increases and viscous forces take over?
Thanks
i have this question which asks me to find the average flow velocity in a pipe, BUT based on flow rate relation and not statistical average
what is the flowrate relation?
I am trying to formulate a plug flow for section of my model. In my model, I've series of CSTR that are linked with the plug flow. The output of the plug flow model is the CSTR model. My main focus is blending CSTR and plug to replicate a residenc time distribution. However, i need a plug flow...
1. The pressure at the start of a 180km stainless steel natural gas pipeline is 4Mpa and at the end is 2Mpa. If the diameter of the pipe is 0.4m, what will be the gas flow rate through the system? (ignore losses other than friciton)
(for natural gas, \rho= 40kg/m3, \mu= 11x10-6 Pas2...
1. The pressure at the start of a 180km stainless steel natural gas pipeline is 4Mpa and at the end is 2Mpa. If the diameter of the pipe is 0.4m, what will be the gas flow rate through the system? (ignore losses other than friciton)
(for natural gas, \rho= 40kg/m3, \mu= 11x10-6 Pas2...
Hello,
I'm currently doing a project were I have to design a tube through which a fluid will flow at > 10 m/s. I am validating my calculations and want to use the correct roughness values. The material is a plastic deposited using rapid prototyping.
I have measured:
Ra = ~7.5 - 8
Rz =...
Homework Statement
every where we require at least 3 variables out of 4(l,d,q,hf)l=length,d=diameter,q=flow rate, hf=head loss due to friction. assume water and e=0.02(roughnss coeff)
what shall happen if 2 of them are known and remaining 2 unknown
ex.known=l,d; unknown=hf,q;
we also know...
Hi guys,
Right, here is the situation. Consider a long coil of pipe containing water with a thermostatic valve at the outlet and a valve (this is the valve in question) at the inlet. The inlet is gravity fed by a large reservoir of water and the question is this: as the water leaves the...
Hi,
literally trying on the off chance that someone could help me.
basically doing an individual project in my third year at nottingham uni. Over the last 6 months I've built a pipe rig to measure the pressure drop over a test section.
Now my tutor is a bit of an idiot, and said the way i...
1. Water is flowing in a pipe from a tank to a nozzle. At some point (A) the pipe tapers from 160 mm diameter to 80 mm at point B over a certain length. Point A is 3 m above point B. The pressure at A is 100kPa and at B is 20kPa, both measured above the atmospheric pressure. The flow rate is...