Pipe Definition and 1000 Threads

  1. C

    Heat Transfer from Air to Dynamic Fluid in Pipe

    I need some help estimating the heat transfer of a system. If I have an exposed length of pipe with a dynamic fluid moving at a constant volumetric rate through a very hot room, what equation is most appropriate to calculate the exit temperature of the fluid? Given: Initial temperature of...
  2. N

    Mass Flow through a 1.5 Pipe @ 300kpa

    Mass Flow through a 1.5" Pipe @ 300kpa Hi, I'm having some trouble with finding the "choke" point of a 1.5" diameter pipe. Conditions: 300 kPa 383 deg K 1.5 in D I've tried using this little guy, http://www.grc.nasa.gov/WWW/K-12/airplane/mflchk.html, with the Mach = 1, and only...
  3. W

    Which roughness value (Rz, Ra, ) to use in pipe flow equations

    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 =...
  4. V

    Determining Flow Rate from a Closed Pipe

    im trying top find the flow rate of water from a closed pipe. one thing that i think i can work with is a hose. there is a hose branching of the main flow pipe, which can be used to clean floor etc. im thinking that i can not open the hose and thus measure the stagnatiob pressure at the...
  5. J

    Recommendations for Pipe Stress Analysis & Design Books

    I'm looking to buy a book or three on pipe stress analysis and design. If you work in this field, please make some recommendations for me. Thanks,
  6. M

    Steam system pipe sizing inquiry

    Good day, My question relates to the use of a pressure reducing station (pressure reducing valve) in a steam system. As those involved in the design know, pipe sizing is carried out starting with the furthest point (the most demanding point of consumption) and sizing shall start from that...
  7. D

    Can PVC Pipe Be Used as a Structural Material for Eco-Friendly Homes?

    I have an "odd" use for pvc pipe. My house is made exclusively of styrofoam and plastic. (and a geodome to boot) I need to stick with this as any other material that was used has failed miserably (wood and steel mainly) my question is, how much weight can a 10' piece of 3" schedule 40...
  8. S

    Magnetic field from conducting pipe

    Homework Statement A long, straight copper pipe of inner diameter 16mm and outer diameter 24mm carries a current of 100A. Calculate the magnetic flux density at distances i)5mm, ii)10mm and iii)15mm from its axis? Answer : i)0, ii)9*10^-4T iii) 13.3*10^-4T Homework Equations I...
  9. P

    Increasing dynamic pressure in a pipe

    I'm starting a project involving a venturi and water, and for the venturi, I need the water pressure to be around 7-10 psi. This means for my water pump, the head height must be around 15-20 ft. Most pumps that fulfill this requirement are either too expensive or are too powerful for my...
  10. C

    Evening out turbulence in a 3 pipe

    Evening out turbulence in a 3" pipe Hi folks, I have a small problem. In my car I'm building new pipes for the pressurized air. On a straight pipe there is a MAF sensor (Mass Air Flow). It consists of a hot wire and a temperature sensor. After the pipes were redone and the MAF sensor was...
  11. M

    Specific Gravity and Pressure in Flowing Pipe

    Homework Statement The following question is from ExamKrackers Physics [an MCAT prep book]. An ideal fluid with specific gravity of 1.0 is passed through a pipe. Along the length of the pipe shown above are attached 3 vertical pipes which are sealed off as shown above. If now a different...
  12. F

    The mystery of the tangent and the radius fluid in spiral pipe on rotating disk

    Here's something simple but also a bit puzzling, let me know if you have any ideas... For clarity, I'll describe three cases before asking the final question (skip ahead if you like). 1. Mounted on a disk are two curved fences, just a few centimetres apart from each other. Between the fences...
  13. J

    Can a Valve Create a Time Lag and Prevent Water Mixing in a Pipe System?

    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...
  14. A

    Max P.S.I. at Bottom of Pipe with 60' Drop?

    To keep it simple: I have a vertical 60 foot drop. I want to create the maximum P.S.I. at the bottom of the pipe possible to run a water wheel or a turbine. If the bottom hole (say 2") and the vertical drop of two pipes is the same will there be a difference in a 4" or a 2" pipe? Note: there...
  15. W

    Formula to compare the strength of pipe versus C channel

    What I'm trying to do is compare pipe to channel as far as lateral strength. I have just received a patent, 7,707,794. It's for a building system of walls, fences, and buildings using steel channels and pipe posts. The current way to build a high security fence using expanded metal panels...
  16. A

    How Long Must Water Stay Underground in PEX Pipe for Geothermal Cooling?

    I want to build a small geothermal cooling unit to cool one small room in my house. If i lay 0.5" pex pipe which is 0.475" ID. The big question is how long does the water flowing in the pex tubing have to stay under ground. Constant ground temperature is about 55 degrees F around my house. I...
  17. D

    Calculating required pump pressure to maintain flowrate in a uniform horizontal pipe

    Homework Statement I am having trouble with calculating the required pump pressure in a horizontal water pipe, 3Km long. i know that the flowrate is 600Kg/s, average velocity 5.6m/s, cross-sectional area of pipe is 0.107143m^2 and losses due to friction average 0.002 per meter Homework...
  18. J

    Can We Use a Thread-Making Machine to Seal a Leaking 20 Offshore Pipe?

    Hello. May I ask if we have the technology to run a thread-making machine on the end of that 20" pipe in the Gulf leaking oil and then screw a 20" cap on it? Is there even a commercially-available 20" threader? Largest I've seen is 6". Granted the oil pressure would initially prevent...
  19. R

    Cross Section of Water Flowing Down Vertical Pipe: The Mystery Unveiled

    hi We all know when velocity of fluid increases then cross section decreases for same mass flow rate and this can be well seen at water flowing from a height as in waterfalls. But why this doesn't happen when water flows down through a vertical held pipe of constant cross section. Well you may...
  20. T

    Calculating Thermal Expansion and Bending in a Pipe

    I was wondering if anyone could provide me with some info on a problem I am facing. I have a pipe of 10m and 16" diameter. It has steam flowing through it, and due to inaccurate desuperheating we have a difference of temperatures at the bottom at top of the pipe. Assuming we have a...
  21. R

    What is the Pressure Calculation for a Horizontal Pipe with Vertical Tubes?

    Homework Statement Water (η = 1.00E-3 Pa*s) is flowing through a horizontal pipe with a volume flow rate of 0.0121 m3/s. As the figure below shows, there are two vertical tubes that project from the pipe. Assume that H = 0.0424 m and L = 0.679 m. Homework Equations No idea how to...
  22. F

    Pipe Flow Question - Fluid Mechanics

    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...
  23. A

    Maximum Pressure of Stainless Steel Pipe

    Hello, I'm looking to experiment with an Electrothermal-Chemical (ETC) system of accelerating a projectile. Basically, it will involve using energetic materials and large amounts of electrical power to create very high pressures inside of a tube in a very short amount of time, behind the...
  24. F

    Sizing Open Pipe System for Equal Head Losses

    If we have an open pipe system that will deliver in total 200 gpm divided in 2 pipes the first pipe is 50 gpm and the second is 150 gpm , the 2 pipes have the same length , if we want to size the pipes where both pipes will have the same diameter , if we do that through william hazen equation...
  25. S

    Fluid mechanics of water in a pipe

    Hello All, I've frequented this forum for various purposes and this is the first time I've decided to post! Hopefully I can find the help or conformation I'm looking for. I may not have all the necessary info, but I feel this is basic enough that I should be able to come up with an...
  26. N

    Understanding Frequency in Open and Closed Organ Pipes

    I have to draw frequency on an open and closed pipe. The top horizontal row is open organ pipe and the second horizontal row is a closed pipe. I have draw the frequency of sound on these but the open entrance of the sound is what is confusing me. Are these correct?
  27. S

    Predicting Heat Transfer from a Pipe: Using Fourier's Heat Conduction Equation

    I am trying to predict the temperature of water coming out of a pipe. I know the temperature of the water going into the pipe. I know the material and characterisitics of the pipe. I know the ambient air temperature. I have explored Fourier's Heat Conduction \mbox {\Huge Q= $\frac {2...
  28. F

    What is the velocity and pressure of water in a narrowed pipe?

    Homework Statement Water with pressure of 120 kPa is flowing through a rectangular pipe with velocity 1.9 m/s. At one point, the pipe narrows to one half of its original diameter. What is the velocity of the water at this narrower point? What is the pressure? Homework Equations v1A1 =...
  29. Q

    Axial velocity for fully developed flow in a pipe

    Homework Statement The book I am reading just randomly states that the axial velocity for a fully developed laminar flow in a pipe is vx=2*u*(1-r^2/ro^2). i am not sure where this comes from. does come from the navier stokes equations? also, is there a book that lists other types of axial...
  30. D

    Max Von Mises Stress Calculation for Pipe Bend

    Hi, I'm trying to calculate the max (von Mises) stress in a 90o pipe bend. Now I know (I think) how to do it for a straight pipe, but can anyone point me in the right direction as to where I can find this analysis for a pipe bend? Thanks in advance.
  31. C

    Flow rate of water out of a pipe

    Hello, Am the owner of a 90 acre man made lake and am trying to calculate the flow out of 12 inch pipe at the bottom of the lake. The lake is approximately 10 feet deep. Can someone point me in the right direction on how to solve this question?
  32. Y

    Need help with finding velocity of a liquid exiting from a pipe

    Homework Statement Part 1: A liquid of density 1392 kg/m3 flows with speed 1.94m/s into a pipe of diameter 0.28m. The diameter of the pipe decreases to 0.05m at its exit end. The exit end of the pipe is 4.2 m lower than the entrance of the pipe, and the pressure at the exit of the pipe is 1.4...
  33. H

    How to Determine Nodes and Antinodes in a Closed Pipe?

    So confused about standing waves in a closed pipe, which is open at one end and closed at the other. The closed end has a node while the open end has an antinode. To figure the wavelength, i use the formula: Lambda = 4L/n where n is the number of harmonic and can only be odd integers...
  34. 8

    Pressure in a pipe of varying size

    Homework Statement Use the picture as a guide. P is the pressure in the pipe, and vi is the speed of a non-viscous incompressible fluid at locations i = 1,2,3,4,5.(For each statement select correctly)...
  35. E

    End correction of the pipe mouth(standing wave)

    Consider a pipe closed at one end and open at the other.a simple model tells that resonance will occurs when the sound wavelength of the resonator is 1/4,3/4,5/4.. of pipe length,by assumption that antinode occurs at the open end.But it comes out that the air at open end isn't completely...
  36. D

    What the electric motor for bend pipe

    what suitable electric motor for create bending pipe machine?. could you give me the idea how to create the machine and easier for the user to use for bending pipe line?
  37. A

    Gas pressure in variable diameter pipe

    This may be an elementary question, but I am still in the elementary stages of physics. My question is this: if you have a 4" fan at the end of a 4" pipe which is sucking air through the pipe, and the pipe narrows to 3" about 24" from the fan, does the 24" section of 4" pipe experience a vacuum...
  38. D

    How do I solve Colebrook equation for friction factor?

    In my fluid mechanics class, we did an experiment where we were asked to measure some values and then, using a Moody Diagram, estimate the roughness of the pipe. Briefly, each trial consisted of allowing water to flow down a thin tube (diameter D=9.5mm) and into a discharge cylinder. A manometer...
  39. S

    Understanding Harmonics and Overtones in Closed and Open Pipe Organ Designs

    This isn't actually a homework/coursework question, but rather a need to clarify a discepancy between my lecturer's notes and a textbook. My lecturer's notes state that for an "organ" pipe, closed at one end, the 1st harmonic frequency will be 4L. For the 2nd harmonic the frequency will be...
  40. V

    Why Does a Bubble Move to the Middle in a Horizontal Pipe?

    Hi people. Please explain me, why in a horisontal pipe (closed) a bubble go to middle, and not stay in any other position? Also what is the difference of forces when this bubble moves from right/left to middle and when it rise from bottom to top. I know bubble rise due to buoyancy...
  41. A

    Advantages of Trunnion Pipe Supports

    Hi all, can someone please tell me what are the advantages of using a trunnion pipe support? I guess that since it is welded on the pipe, it will prevent pipe movements in any directions, but then why would you use a trunnion instead of an anchor? Thank you!
  42. W

    Determining the distance of a pipe by the length of an echo

    How could I determine the length of a pipe by playing a certain frequency into it, then measuring how long the echo is audible?
  43. H

    Convection over horizontal pipe in air

    I am working on a problem involving heat transfer from a horizontal pipe in air. I am having trouble with it and not getting the solution I expect, and I think it is because of the convection component of the heat transfer. The general formula I am following for convection from a horizontal pipe...
  44. J

    COMSOL: Periodic inlet flow rate in a pipe

    Hi all - I would like to add a periodic inlet flow rate (Q(t) over an entire period T) as a BC in COMSOL. Does anyone know how to do this in 2D axisymmetric Transient Navier Stokes through COMSOL? I'm aware of the periodic boundary condition option available, but really just don't know how to...
  45. D

    Bemoulli equation ( flow in pipe)

    the bemoulli equation states that the energy per unit weight for a frictionless slow is constant. water at: 30degree c = 0.801kgm-1s-1 80degree c = 0.357kgm-1s-1 Radiator 15kw delta T= 5degree c cp = 4.2kj/kgk pipe diameter 40mm is the flow in the pipe laminar or turbulent at 30...
  46. P

    Flow Through a Pipe: Modelica Model with Unequal Inlet-Outlet Areas

    Hello guys, I need to model a pipe in modelica. Now modelica has its own fluid library where i can find a model of a pipe. But i need to model a pipe which has unequal inlet and outlet area. The outlet of the pipe is smaller than the inlet. Since mass going in the pipe=mass going out, hence...
  47. P

    How Does Pipe Tapering Affect Pressure and Flow Rate in Fluid Dynamics?

    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...
  48. A

    How to find the flow rate trough a pipe using pressure drop

    Hi, I want to know how high the flow rate trough a pipe is (outlet), but I only now the pressure difference (0.7MPa or 7 bar), and the diameter of the pipe. At what speed (or for that matter volume) does air leave a pipe when the pressure difference is 7 bar, and the diameter is 25.4mm...
  49. R

    LaTeX Making Vertical Lines in Table - Latex

    Dear all, I want to make a vertical line in table.. I use this following latex codes \begin{table}[h] \caption{Some caption.}\label{namelab} \vspace{2mm} \centering \begin{tabular}[width=1\textwidth]{ll|cccc} \hline\hline \multicolumn{2}{c}{2~col} & par~1 & par~2 & par~3 & par~4\\...
  50. V

    Fluid problems - pipe like questions

    Fluid problems - " pipe " like questions Homework Statement A fireman climbs a 8 m high ladder carrying a 5 in diameter hose that has a 1.4 in diameter nozzle. The pump has an absolute pressure of 4 atm. What is the water velocity from the nozzle? Assume that water is incompressible, its...
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