Fluid Definition and 1000 Threads

  1. M

    A Is Transient Flow Caused by Changes in Velocity's Direction in Pipelines?

    Hi every one; Transient [Fluid Transient in Pipelines] is result of changing in momentum and momentum is result of changing in velocity. Velocity is a vector parameter. It means that Velocity's change is due to changing in velocity's quantity or velocity's direction. All discussions about...
  2. S

    Terminal Velocity of a Cylinder Freefalling Through a Fluid

    Hello :) I am an engineer and I am trying to analyse a system which basically contains a cylindrical body free-falling through a body of static water beginning with zero velocity. I am ultimately trying to find what the velocity of the object would be at a depth of 20m. In order to do this I...
  3. faradayscat

    How Does Air Pressure Affect Fluid Levels in a U-Shaped Tube?

    Homework Statement [/B] Suppose we have a u-shaped tube filled with water, with oil added at one end which disturbs the equilibrium. Now say one end is blocked off and the other is exposed to air flow which reduces the pressure above the water and causes the water to climb back to equilibrium...
  4. V

    Flux Integral of a Fluid Rotating about an Axis

    Homework Statement We have a fluid with density ρ which is rotating about the z-axis with angular velocity ω. Where should a unit square, call it S, be placed in the yz-plane such that there is zero net amount of fluid flowing through it? Homework Equations...
  5. M

    B Is the Universe a Type of Fluid?

    Hello, everyone I am new to the site I was wondering if the Universe and gravity are types of fluid? As you can read I am not a cosmologist or even a physicist but I love science
  6. Umair Shariff

    Fluid Dynamics: Orthostatic Blood Pressure Equation

    Hi everyone, I have been hunting all over the Internet for an explanation to changes in the blood pressure when sitting, standing or lying down. I know the complex mechanisms that are involved but I need an equation for an ideal system with the heart in the middle and the pressure that needs to...
  7. Titan97

    Loss in energy of a ball dropped in a fluid

    Homework Statement Two identical balls A and B are dropped from rest into a tall column of viscous liquid. Ball A is dropped from the surface of the liquid while ball B is dropped from a small height ##h## above the liquid. Let ##E_A## and ##E_B## be the loss in mechanical energy of bal A and B...
  8. Arsen

    Fluid Dynamic. Force on particles in carrying fluid (liquid)

    Good day to all! I have a question : We have a flowing fluid ( liquid ) with known pressure, flow in the pipe ( pump is pumping it). There are some spherical microparticles in the liquid, let's say 10-15 microns. I want to create force to stop them moving! Will the pressure force be in the form...
  9. M

    Fluid mechanics - Pascal's principle

    Homework Statement Mercury is poured into a U-tube as shown in Figure a. The left arm of the tube has cross-sectional area A1 of 9.4 cm2, and the right arm has a cross-sectional area A2 of 4.50 cm2. One hundred grams of water are then poured into the right arm as shown in Figure b. (b) Given...
  10. M

    Forces appearing on the pipe when a fluid flows in it

    Hi, I study linear momentum. But I cannot understand enough that how can forces appear on a pipe when fluid flows in the pipe? Fluid have a momentum as m*v how can forces appear on the pipe. I cannot demonstrate the situation in my mind. How can I find a demonstration or a free body diagram for...
  11. M

    Fluid mechanics civil engineering

    As shown in the attached image, a tank has an inclined wall at an angle of 450 to the horizontal. On this wall, there is a 1m square door that is hinged at A and has a simple latch at B. The distance between A and the free surface of sea water measured along the inclined wall is 2 m. (Specific...
  12. C

    Why is Specific Gravity (SG) Needed in This Buoyancy Calculation?

    Homework Statement [/B] When asked for the bouancy of a hollow cylinder, containing air, submerged in ocean water. outer radius R. Length of cylinder = L The Material of the cylinder is neglected. I'm thinking the Bouancy (Force) = ρ ⋅ g ⋅ v where v = LπR^2 and therefore F = ρgLπR^2 But the...
  13. T

    Lowest Kinematic Viscosity Fluid - High Pressure Gas

    I am trying to determine which fluid to use in an experiment. An important aspect of the experiment is the ratio of inertial forces (due to mass) vs the viscous forces that the fluid will experience Amongst common liquids the lowest I can see is Acetone with a kinematic viscosity of 0.41 cSt...
  14. Alfreds9

    Water evaporation, temperature, wind and heat capacity?

    Hi, I'd like to know how I'd put together, either elegantly or at least in physical terms, that surely water evaporation in a large pool of V volume and S surface is influenced by wind (increased by it as opposed to having side barriers), temperature (increased by direct sunlight as opposed to...
  15. G

    Engineering Which Book Best Aligns with These Fluid Dynamics Topics?

    I'm looking for a book to really help hit home what my fluids class is teaching because I'd like to eventually learn the Navier Stokes Equation. Syllabus: 1. Introduction, definitions, fluid kinematics 2. Hydrostatics, including nanometers, Bourdon gauges and pressure transducers 3. Control...
  16. S

    Solve question using Excel or Matlab

    water moves over a stationary horizontal flat plate of one-meter length. if velocity of water is 1 m/s, draw boundary layer and friction coefficient versus x for this plate. hint: start your curves from x=1cm.Professor asked us to do it in Matlab or Excel and I'm not sure I understand how to...
  17. Villa

    In fluid mechanics what does pressure energy mean?

    In Bernoulli equation we use pressure energy... Pressure* volume gives the unit of energy... But what does this mean... If someone says it is potential energy per unit volume, then what does datum head refers to?... Please help... Can't go ahead without having thorough knowledge about this..
  18. D

    Fluid speed in a straight pipe

    Hello everyone I have a simple question regarding how to calculate the speed of a fluid in a normal pipe with a constant cross-section If we are given the pressure difference at the two ends of the pipe (P1 and P2) is it possible to calculate the speed of the fluid? (I think I can imagine this...
  19. G

    High-pressure compression of liquids

    Hello, My memories of fluid mechanics are very rusty and therefore I was wondering if you could help me with this hypothetical problem. Let's say I want to generate very high hydrostatic pressures in a liquid (of order of 400 kbar). Would it be enough to do the following: take a rod weighting 1...
  20. J

    Is there a difference between redirection and converging flow in fluid dynamics?

    Fluid or sleeve bearings use an off center shaft location to generate a hydrodynamic wedge in direction of rotation. This converging fluid causes higher pressure and can support a load applied normal to shaft axis during rotation. This action appears to be similar to the hydrodynamic support of...
  21. S

    Plotting pressure distribution of fluid flow in a pipe

    Hi all, I am analysing the flow of water in a subsea pipe, and have been getting stuck in trying to solve the energy equation to plot a temperature distribution across the pipe diameter I have derived the equation as such seen in my attachement. But my main question is how should/would I...
  22. B

    Force exerted by a agitated fluid on vessel wall

    How can I calculate the pressure exerted by a fluid on the walls of the vessel that is being agitated. The vessel is not pressurised. I have to calculate the resultant pressure on the walls to calculate the thickness of the vessel walls.
  23. S

    MHB Combination of field and particle methods for fluid dynamics

    hello, in numerical fluid dynamics there are field methods like finite-volume, finite-element, etc. and particle methods like Smoothed-Particle-Hydrodynamics – SPH and others. Both approaches have advantages and disadvantages depending on the application. Both, in principal completely different...
  24. thebosonbreaker

    I Non-Newtonian fluids at the quantum level

    I am intrigued by the diversity of Non-Newtonian fluids and need to ask a question. Can anyone provide me with a breakdown of what goes on at the quantum level as the Non-Newtonian fluid bounces up and down on top of the speaker in the video I have embedded. What I would like to know is...
  25. datf

    Solving Fluid Dynamics Questions: Pump Similarity Laws and Efficiency Comparison

    Hi guys, please help me with these questions. I've been racking my brain for days but I'm not sure of the answers. 1) (Assume that pump similarity laws are valid and that the effects of Reynolds number (Re) are small.) A centrifugal pump operating at speed N is combined in series with an...
  26. Mingsliced

    Fluid Mechanics - Head Loss Due to Friction

    Homework Statement This is simply a sanity check concerning the system described and attached. My concerns are detailed within my attempts at the solution. Any guidance will be greatly appreciated! The diagram attached represents a process for which a pump and associated pipe work require to...
  27. F

    Force of Reducer on Fluid Flowing Right

    Homework Statement is it correct to say that the force exerted by reducer on fluid directed to the left because of the fluid move from left to right ? Homework EquationsThe Attempt at a Solution
  28. UMath1

    I Is the Force Applied by an Object on a Fluid Equal to the Buoyant Force?

    If you place an solid object on a fluid, is the force it applies to the fluid equal to the buoyant force? I would have thought that it applies a force equal to its own weight but that would mean that the force applied to the object by the fluid, the buoyant force, would not be equal and opposite...
  29. S

    Fluid Flow Equations With Real Values

    Hi, all I am working on a project that involves analyzing fluid flow behavior in oil & gas pipelines. I am interested in calculating and plotting the velocity profile, and also(pressure distribution, temp distribution) Having studies fluid mechanics last year I am aware of the EOS for fluid...
  30. tomdodd4598

    Stokes Law/Drag Force corrections?

    Hi there, I have recently been experimenting with solid metal spheres being let to fall through fluids of different viscosities and have recently been introduced to the 'Ladenburg correction'. This correction multiplies the measured velocity of the sphere to obtain the 'correct' velocity used...
  31. L

    How to Determine Flow Rate in a Pipe Using Fluid Dynamics?

    Homework Statement http://imgur.com/DSBFIeO I want to find the flowrate through this pipe based on the pipe's diameter, height of the pipe and the pressure difference. I tried to use Bernoulli, but since the diameter on either end is the same, the terms cancel out. I guess Bernoulli's equation...
  32. C

    Stress tensor for non-Newtonian fluid

    How does one setup the stress tensor for a non-Newtonian fluid? I know that for any fluid the normals should be the pressure and for a power law fluid the shear stress in the direction of flow is related by K(du/dy)^n. Does this mean that all other components are 0 for a symmetric pipe or...
  33. W

    What is the formula for the weight of a fluid block?

    Homework Statement why the formula of weight of fluid block is given by the formula of ρg[ (R^2) - pi(R^2) ] 1? what does the 1m mean here ? shouldn't it = ρg (pi) (R^2) h ? 2. Homework Equations The Attempt at a Solution
  34. W

    Supporting Fluid: Reducing Shear Stress with Wall

    Homework Statement why the fluid need the wall to eliminate the shear stress? Homework EquationsThe Attempt at a Solution is it because if there is no wall to support teh fluid , the fluid would move continously , resulting the shear stress act on water?
  35. C

    Solve UROV Fluid Mechanics Homework: Max Vel, Time, Distance, Drag Force

    Homework Statement Im working with a UROV and I have a technical scenario that I am supposed to solve. It seems pretty easy but i keep getting ridiculous answers. Assuming a max thrust of 5 N for 1 motor/propeller, for the forward direction only, use the above information to determine the Max...
  36. KingDaniel

    Why should an ideal fluid be incompressible?

    Hi, I read that an ideal fluid needs to be frictionless and incompressible. Please explain why, especially the incompressible part? Thanks
  37. prashant singh

    What is the Best Book for Fluid Mechanics from Beginning to Advanced Level?

    which is better fluid mechanics book , frank white or munson from complete beginning to the advanced level.
  38. S

    How Does Fluid Viscosity Affect Spring Oscillation Period?

    So there is this ball held on a spring. It's radius R = 0.015m , and density ρ=7800kg/m^3. It's oscillation period in air is 1.256 seconds and in the fluid it changes to 1.57 seconds. Find the viscosity of the fluid considering that the drag force obeys Stokes law. I first found the spring...
  39. T

    Solving for Air Speed in an Air Duct

    Homework Statement A 15 cm. radius cylindrical air duct is used to replenish the air of a room 10 m.*6 m.* 3m. Every 10 minutes. Determine the speed of the air through the duct in m/s. A1=15 V1=? A2=19 V2=0 Homework Equations A1V1=A2V2 The Attempt at a Solution 3.14*15^2 * ?= 19*0=...
  40. sa1988

    Acceleration of fluid particle

    Homework Statement Find acceleration for a general point (x, y) at time t, in the velocity field u = (y, t-x) Homework Equations Du/Dt = ∂u/∂t + (u⋅∇)u The Attempt at a Solution ∂u/∂t = (0, 1) (u⋅∇)u = [(y, t-x)⋅(∂/∂x, ∂/∂y)](y, t-x) = (0 + 0)(y, t-x) = (0, 0) Thus Du/Dt = ∂u/∂t +...
  41. jdawg

    Fluid Mechanics:Volumetric flow rate and average velocity

    Homework Statement . Air, at a flow rate of 30 [N/s], flows through the reducer shown below. In the 300 [mm] diameter section of the pipe the specific weight of the air is 9.8 [N/m3 ]. When flowing through the reducer the pressure and temperature will fall causing the air to expand and...
  42. E

    Ball in accelerating tank with fluid

    T1. Homework Statement a wooden ball of mass m is kept inside water by the help of a massless string shown in the figure. One end of the string is fixed at the bottom of the vessel. when the vessel containing the water is accelerated upwards with acceleration a , will the tension increase and...
  43. sa1988

    Fluid dynamics, solving ODE to find particle path

    Homework Statement A time-dependent two-dimensional fluid flow is given, in a Cartesian coordinates system (x, y), by the velocity field: u = (y, t-x) Show that, at time t = 0, the streamlines of this flow are circles centred on the origin. Find equation of the streamline that passes through...
  44. C

    Fluid Mechanics Videos: Resource for Video Lectures

    Hello, does anyone know a good resource for video lectures on the subject of fluid mechanics?
  45. S

    Fluid Dynamics - Pressure at the end of a syringe

    Hello there Physics Forum! This is my first post here. This problem has been boggling me all day and I'm need of help in piecing together what I've come up with so far. I'm currently working on a personal project related to paint spraying. In this project I'm using a syringe & needle to feed...
  46. jdawg

    Fluid Mechanics: Cart and tank of water

    Homework Statement A cart has a tank of water on it which has a nozzle. Water jets out from the nozzle onto a turn vane oriented at theta = 30° which deflects the flow upward. The cart is held stationary by a rope as shown in the image below. Find the force in the rope if the velocity of the...
  47. jdawg

    Fluid Mechanics Velocity at Outlet

    Homework Statement Water flows through a 1.5 [in] diameter pipe. In a 1.5 [ft] section of the pipe water is injected through the porous walls into the pipe at a velocity of 3 [in/s]. What is the average velocity at the exit if the inlet velocity is 6 [ft/s]? Homework EquationsThe Attempt at a...
  48. M

    Calculating Pipe Diameter for Desired Pressure in Inclined Fluid Flow

    The question: There is a 650m long tube on a 1 degree incline. At one end of the tube is a pump that alone has a volumetric flow rate of 750 g/min. The fluid in question is water and its a PVC pipe. What diameter does this tube need to be in order to have 25 psi on the top end of the tube...
  49. M

    Nontoxic, high transmittance, high density fluid

    Hi, I'm looking for a liquid that is nontoxic, high transmittance, has a specific gravity higher than 1.3. Here is the catch. I'm using it to separate resin, so it can not dissolve or react with resin. there was a similar topic on high density fluid on other forums, but I'm using it...
  50. CivilSigma

    Separation of Particles in a fluid flow?

    Hello, I'm doing some online research on fluid flow in waste water treatment. One of the problem I'm trying to find information about is how can visible particulate matter be separated within a liquid. I saw the following picture: What fluid concepts are going here that allow the grit to...
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