Fluid Definition and 1000 Threads

  1. C

    Calculating Gravitational Potential Energy of a Fluid Above a Reference Line

    I got a quick question regarding the potential energy of a fluid (see picture). If I want to express the potential energy of a fluid (with a given volume) above the reference line x, using nothing but the given variables/constants, would this be the correct way to do so? picture
  2. crador

    Fluid Dynamics pipeline with a venturi injector

    Hey guys, I've been wracking my brain for a while, and thus I have landed here yet again. My problem is the following: Say you have a pipeline with a venturi injector, and intermittently a large tank of water with a portion of air on top -- I.e. a closed circuit communicating between the...
  3. A

    Determination of density at a depth in a compressible fluid.

    Determination of density at a depth in a compressible liquid. Hi all, Let us consider a tank containing some compressible liquid with bulk modulus K and having density at its surface s. Consider some part of liquid with volume V, a depth h below the surface. Due to liquid above it there...
  4. mattyboson12

    Understanding Bernoulli's Equation for Fluid Dynamics with Electric Pumps

    Hi, am having a few problems applying bernoulli's equation when an electric pump is involved. I have attached a picture of the question. I understand how to apply bernoullis for venturi and pitot tubes but when it involves work being done on the system eg. a water pump, fan exhaust I don't know...
  5. Q

    Fluid Mechanics and hydraulic lever

    Homework Statement In a hydraulic lever consisting of two ideal fluid lined cylinder/pistons with a fluid filled line coupling the two cylinders, the output force is 100 times the input force. For 1 Joule of work done on the input side, the work done on the output side is (in J):Homework...
  6. K

    Analogy between fluid dynamics and electromagnetism

    I've recently heard of an analogy between fluid dynamics and electromagnetism in which the velocity flow field is identified with the magnetic vector potential, (and therefore the vorticity is identified with the magnetic field), and the vector \omega \times v is identified with the electric...
  7. B

    Best Fluid to Use for Charpy Impact Testing

    Hello Guys, I have been doing Charpy tests for the past couple of months and notice that I can't get rid of the water that keeps freezing and sinking to the bottom of the my chiller. It's becoming more of a hassle that my agitator stops due to the water freezing at the bottom of the chiller...
  8. B

    Fluid dynamics in horizontal pipe

    There's a figure that comes with the question but I'm having trouble attaching it so I will describe it the best I can. There is a large cylinder labeled the reservoir. A horizontal pipe is connected near the base of the reservoir and it is open at the other end so fluid flows out (point B)...
  9. M

    Standard Sci-Fi Battles Using Fluid as the Medium?

    Hello! I'm working on creating a sci-fi setting for a tactical space combat video game and short story series, and I had a few questions I couldn't find much info on after googling. I'll be playing a little bit loosely with the laws of physics for the sake of gameplay and storytelling, but I...
  10. B

    Bernoulli's equation, static fluid, gauge pressure problem.

    Hi, I haven't done many problems of this nature so there are a few steps in my working that i'd like to check are acceptable/agree with what the question implies. Homework Statement A water tower is a familiar sight in many towns. The purpose of such a tower is to provide storage...
  11. X

    What Is the Net Inward Force on a Sinking Barrel?

    Homework Statement Suppose a cylindrical barrel falls off a ship and sinks to the bottom of the sea at a depth of 1.61 km. Assume that the seawater is incompressible, so that its density at the bottom of the sea is the same at the surface :1020 kg/m^3 If the pressure inside the barrel is...
  12. X

    How Do You Calculate Net Inward Force on a Submerged Barrel?

    Help with fluid mechanics!? Suppose a cylindrical barrel falls off a ship and sinks to the bottom of the sea at a depth of 1.61 km. Assume that the seawater is incompressible, so that its density at the bottom of the sea is the same at the surface :1020 kg/m^3 If the pressure inside the...
  13. C

    Calculate the volumetric flow of a fluid

    How could I calculate the volumetric flow of a fluid due to the weight of a piston in a cylinder? At first moment i I thought the Hagen-Poiseuille equation, but I'm not sure. Any suggestions?
  14. F

    How Do You Calculate the Height of Fluid in a Horizontal Cylinder?

    Thanks in advance! I have problem that is causing me a headache to no end. In a cylinder, if one knows the total volume of cylinder and total volume of fluid in said cylinder, how would the height of this fluid be computed? I have no problems calculating volumes based on height, but the other...
  15. R

    High density, Less-Volatile, High Heat capacity Fluid

    hey :smile: I am a college student and am looking for a liquid having the following properties at very low temperatures (probably around 100-150 K) - 1) Very high density 2) Very high temperature of vaporization 3) Less- Volatile 4) High specific heat capacity
  16. C

    Influence of magnetic fluid in magnetic force

    Looking for a way to increase magnetic forces in electrical devices, an option is reduce the air gap, but some times it is not a practicable solution. The question is what happened if we put a ferrofluid between the magnets? Imagine the following situation: a closed volume composed by a...
  17. C

    Minor head loss for turbulent vs. laminar fluid flow

    Hi, I need clarification on the difference in head loss for turbulent flow and laminar flow. I understand how the head loss due to friction is different for the two regimes. For friction head loss, the friction factor is 64/Re for laminar flow, and a more complex formula for turbulent flow. I...
  18. B

    How Does a Fluid Oscillate in a U-Tube with Mercury?

    A u tube open at both ends and a uniform cross section contains a mas of mercury,m and a density of 'rho' if the level is slightly disturbed show the surface oscillates with a periodic time of Tn=2pi sqrt[(m/2g'rho'a)] where a is the cross sectional area. i understand how to do this...
  19. R

    Air Flow through cooling tower- fluid mechanics problem

    Hey everyone! I am working on improving natural draft counter flow cooling tower efficiency as my final year B.E. project. I came across a research paper that said that at transverse cross section of the tower, above drift eliminators, the air velocity decreases from the periphery to the...
  20. M

    How does photochromic fluid work

    Hi all, I purchased this photochromic fluid I have been trying to get to the bottom of how it works. From wikipedia http://en.wikipedia.org/wiki/Photochromism For example, the spiro form of an oxazine is a colorless leuco dye; the conjugated system of the oxazine and another...
  21. T

    Boundary Conditions for an inviscid fluid at a fixed boundary

    This is my first post so I hope this in the right place. I am fairly sure this is quite a straight forward question but I having trouble working out the details of it. "State the boundary conditions for an inviscid fluid at an impermeable fixed boundary x_3-h(x_1,x_3)=0 where we do...
  22. B

    Calculating Fluid Force of Triangle Submerged in Water

    Homework Statement Find the fluid force of a triangle with base of 6 ft and height of 4 ft submerged vertically into a body of water,vertex down, to a depth of 3 feet. Homework Equations from c to d W ∫ h(y) L(y) The Attempt at a Solution I set up the triangle on an x and...
  23. Entanglement

    Exploring Superfluids: Physical Explanation and Properties at Zero Kelvin

    Some fluid act weirdly at zero kelvin like Helium 1- it loses viscosity 2- flows upwards along the wall against gravity ! And there is a property I'm not sure about, that it can't be held in a container because it leaks out of it. However what's the physical explanation for all of that...
  24. J

    What can a PH meter tell you about the quality of fluid

    What can a PH meter tell you about the quality of fluid it is measuring?
  25. A

    Hydrostatic Fluid- Linearly Accelerating Slope

    Homework Statement An open rectangular tank contains water up to about half of its depth. This tank accelerates at a=2.20 m/s^{2} up a slope α (alpha), which causes the free water surface to form an angle θ (theta) with the original horizontal plane. What is the α angle of the slope?Homework...
  26. T

    What is the Relationship Between Pressure and Height in Fluid Mechanics?

    The correct answer to this problem is h2 = h1 but I don't get it. According to what I understand, F=p/A So for the Tube on the left: F1 = P/A = (\rho*g*h1)/A1 For tube on the right: F1 = P/A = (\rho*g*h1)/3*A1 I get h2=3h1 (i know if you think about it this does not make sense...
  27. P

    Finding A_n in a Fourier-series Approach to Viscous Fluid Slowing Down

    Homework Statement A fluid of viscosity \nu is rotating with uniform angular velocity \Omega inside a cylinder of radius a that is also rotating. At time t = 0, the cylinder is brought to a rest. The circular motion of the fluid is gradually slowed down due to the viscosity; show that u_\theta...
  28. T

    Toppling of cylinder containing fluid

    Homework Statement A light cylindrical vessel of radius r is kept on a rough horizontal surface with sufficient friction so that it cannot slide but can topple. It is filled with water up to a height 2h and a small hole of area a is punched in it so that the water coming out of it falls at the...
  29. W

    Linearly accelerating hydrostatic fluid

    Homework Statement A cart is acclerating to the right with a=3m/s^2. Fluid is in hydrostatic state. Find the force on the back wall. Cart goes .8m into the page. In the image dotted line is free surface when cart is stationary. Homework Equations \vec{\nabla P}=\rho (\vec{g} -...
  30. L

    Aerodynamics HW - fluid particles acceleration based on stream functio

    Homework Statement prove that with flow in a corner, with stream function ψ=Axy, particles are accelerating per \frac{DV}{Dt}=(A2(x2-y2))/r; A=const; r-distance from the center of the corner Homework Equations Vx=U=\frac{∂ψ}{∂y} . . Vy=V=-\frac{∂ψ}{∂x}...
  31. J

    What would happen to the accuracy of a float gauge if the fluid it is

    What would happen to the accuracy of a float gauge if the fluid it is measuring is heated?
  32. W

    Damping Force in a piston: Ideal Gas versus a Fluid

    I was in my physics of the human body class and we got on the topic of pistons. It was given to me that the dampening force pertaining to such a piston filled with a gas is proportional to the square of the velocity of the piston; however, for fluids it was given as simply proportional to the...
  33. W

    Moment produced by a fluid of varying density

    Homework Statement Find F, the force acting at the top of the gate. The gate is 2m high and 2m into the page. It is hinged at the bottom (red dot in the diagram) Density of fluid varies linearly. 1000 kg/m3 at the top and 1600 kg/m3 at the bottom (depth of 4m) Homework Equations...
  34. T

    Basics of Fluid Mechanics and Pressure

    Hello I am having difficulty in comprehending the basics of fluid mechanics . I have few questions which I would like to put one at a time , so as not to create any confusion . In the following attachment , a container with a liquid rests on a surface .I would like to understand what are...
  35. P

    Fluid Mechanics and Venturi meter

    Homework Statement A Venturi meter is constructed with an inlet diameterof 100 mm and a throat diameter of 40 mm. The meter must be calibrated prior to leaving the factory. The meter is installed in a 100 mm diameter water main with a...
  36. N

    Fluid Mechanics and order of magnitude calculation

    Hi In my lecture notes we making some calculations and all terms \mathcal O(M^3) are to be thrown away. Here M is the Mach number. Now, there is the expression (u denotes the velocity): uu\partial_t \rho \approx \rho_0 uu\nabla u which in my notes are thrown away because they claim it is...
  37. N

    Solving Fluid Dynamics Pressure at Different Speeds

    Homework Statement If the pressure reading of your Pitot tube is 17.0 mm Hg at a speed of 150 km/h, what will it be at 700 km/h at the same altitude? Homework Equations The only eq I could think if is p = p2+ 1/2 density (v2^2 - v1^2) But I don't know the density The Attempt at...
  38. J

    Temperature of fluid flowing through pipe

    Is there a mathematical relation for the temperature change when a fluid flows through a pipe from one end to another? I am not aware of any equation in thermodynamics for this, but I would guess the following parameters are important : 1. cross-sectional diameter of pipe 2. viscosity 3...
  39. gfd43tg

    Pressure drop at power station pumping power law fluid

    Homework Statement The Black Mesa pipeline transports 660 tons / hr of solid coal ground to 8 mesh (2.4 mm) as a 50 wt % slurry in water with an estimated sg of 1.26 for 273 miles across northern Arizona. The pipeline ID is 18 inches and the slurry flow rate (coal and water) is 4200 gal/min...
  40. B

    Understanding Fluid Pressure: Get Help Here!

    Homework Statement Homework Equations fluid pressure = fluid density * depth * gThe Attempt at a Solution My understanding is that fluid pressure at any two points at the same depth is equal, for a fluid at rest. But because one end is open, the pressure at point C is less than B and equal to...
  41. I

    Very basic fluid statics and dynamics question

    consider the image on the drawing at the top (above the yellow arrow) if i had some non-compressible fluid enclosed in a pipe like container that looped back in on itself (as shown in figure), and if the container was non-elastic, when i rotate this container filled with fluid such that...
  42. M

    How Do You Calculate Shear Stress in a Flowing Fluid?

    Homework Statement Water at 20 degrees C flows in a 0.8cm diameter pipe with a velocity distribution of u(r) = 5[1-r2/(16x10-6)]m/s. Calculate the shear stress on (a) pipe wall (b) at a radius where r = 0.2 cm (c) at centerline of pipe Homework Equations Shear stress = viscosity x du/dr...
  43. N

    Determining volume of fluid dispersed from a broken pipe

    I have the pipe size, flow rate, and a duration. How can I figure out the amount of fluid that was released from the pipe?
  44. S

    Fluid dynamics, Pipe Flow, Hagen Poiseuille, Darcy's equation

    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...
  45. W

    Fluid Mechanics: Tilted Axes and Weight of Gate

    Homework Statement AB is homogeneous with mass of 180 kg, goes 1.2m in the page and is hinged at A and resting on aa smooth bottom at B. All fluids at 20 C. Find height of water that will result on 0 force at B Homework Equations M_s = \int\int_s \ (\vec{r} \times \hat{n} )PdA...
  46. B

    Calculating Air Speeds in a Venturi Tube Using Conservation of Fluid Mass

    Homework Statement Air is blown through a circular and horizontal Venturi tube, as shown in the figure below. The diameters of the narrow and wider sections of the tube are given, and the height h of the mercury column is measured to be 1.00 mm. What are the air speeds in the wider and the...
  47. F

    Fluid Inside an Ideal Sphere: What Happens?

    Hi all! Imagine you have an ideal sphere (made of steel or plastics). Then fill it completely with some fluid, e.g. water. Then rotate it very fast. What happens to a fluid inside? I suppose that it will try to change its shape (from spherical to flat). But there is no space for any size...
  48. S

    Mechanism of Oobleck - Non-Newtonian Fluid

    Hi, What is the molecular-level mechanism of shear-thickening of oobleck (cornstarch-water paste)?
  49. G

    Not enjoying thermo, will I enjoy fluid mechanics?

    I'm pondering courses for the autumn and I'm at a bit of a crossroad. Doing an intro thermodynamics class right now which involves all the stuff I don't really enjoy - measurements, looking stuff up in tables, memorization, etc. Very non-theoretical. It feels like an AP chemistry class...
  50. S

    Why you have to infuse 3 times the fluid loss with crystalloids?

    Hello everyone I still don't understand crystalloids 1) Let's say someone lost 100 ml of blood due to accident. If you are giving crystalloid therapy, why do you have to infuse 3 times the amount. What I think is when you give crystalloids IV, they go into extravascular and...
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