Fluid Definition and 1000 Threads

Hi everyone, I have to answer some question about a physics lab..here are the questions A tank is empty by a pipe and we measure the height (y-y0) of fluid in the tank as a function of time. We obtain this graph ( I join the graph) We can find the relaxation time with the relation : with...

So, here's the problem I've come up with that I wanted to solve. We're going to be using a polar coordinate system for this one. A will represent our angle theta, and r will represent our radial coordinate. We are going to be looking at a non-compressible Newtonian viscous fluids. I'll now put...

Homework Statement This is not a set question but a problem statement for an investigation. I am trying to understand the physics behind drinking through a straw, but not when the straw is fully submerged in the drink but at the end of the drink when the liquid and air both pass up the straw...

Homework Statement A reasonable approximation for the two-dimensional incompressible laminar boundary layer on the flat surface in Fig. P4.17 is u ≈ U(2*(y/δ) - 6*(y3/δ4) + y4/δ4) δ = Cx1/2 where C is a constant y ≤ δ Homework EquationsThe Attempt at a Solution Incompressible so...

Hi PF! So after scaling Navier-Stokes for a flow over a flat plate we ultimately arrive at ##f f'' + f''' = 0## subject to ##f(0)=0##, ##f'(0)=0##, and ##f'(\infty) = 1## where independent variable is ##\eta##. The source I was reading is trying to reduce this BVP to an IVP. Thus they suggest...

I was wondering how a boundary layer would be dissipative of momentum if it was under the influence of a positive heat gradient. I understand that the reason that we don't see the boundary pressure equal the stagnation pressure is that the boundary is dissipative (so excess pressure above...

my first post having just joined! Problem statement - what curve describes the surface of a rotating liquid? Stirring my cup of coffee years ago sparked this thought. Question - is the way to solve this problem to use variational calculus, or fluid dynamics? I have always thought the former but...

Homework Statement Homework Equations x = (x1,x2,x3) are the coordinates of the current configuration and X = (X1,X2,X3) are the coordinates of the reference configuration where x = y(X,t) where y is a deformation of X. The Attempt at a Solution (a) taking the partial derivatives of xi with...

http://phys.org/news/2014-04-liquid-spacetime-slippery-superfluid.html What if spacetime were a kind of fluid? This is the question tackled by theoretical physicists working on quantum gravity by creating models attempting to reconcile gravity and quantum mechanics. Some of these models predict...

The no slip condition has been described as the adhesion of a fluid to a solid surface setting the relative fluid velocity to zero - cohesion (viscous stress) between fluid elements spreads evenly the velocity gradient through the boundary to the free stream. This also infers that the pressure...

I'm trying to make a low temp heat exchanger but feeling difficulty in selecting a type of organic fluid some are very toxic, some are not environment friendly. Is there anyone who could suggest me the working organic fluid but it should not be water.

After doing extensive research, I am still confused about Control Volumes. Say that there is water flowing into a cup at a steady rate, and I am required to illustrate the momentum and mass flows, as well as the forces, how would I approach this? I have seen examples of Control Volumes but they...

How would one calculate the drag on a projectile (in this case a 1cm3 cube) that was launched at 0°. The vertical drop, initial velocity, distance, and time (taken to travel distance) where measured. I want to say that I could compare these experimental drop (bellow hight that projectile was...

Homework Statement (This is more of a discussion question) [/B] My question is, if we have a pipe between two reservoir A and reservoir B (Height of A > height of B) , then if flow in the pipe is to happen from A to B, what sign would the pressure sign be at any point in the pipe? Homework...

Hello What is 'Choke Station' in fluid pipelines? Is it a station in which pressure of fluid is decreasing? Is it a kind of Pressure Reduced Valve?

For example, in this question.. A 11 L rigid container contains 10-kg of R134a at 100kPa. Determine the temperature and total enthalpy in the container. Why can we just assume that the temperature we're looking for is T_sat, how do we know this isn't a compressed liquid? How do we know it...

Hello, I'm a bit rusty with my fluid mechanics and can't seem to find the answer anywhere. Basically I have a pressure wave traveling in a liquid at the speed of sound through a pipe of the shape shown in the attachment (basically a semicircle of constant cross sectional area and then a cone of...

I'm working on an idea in product development, though being still a fairly new student in this i still am left with a lot of questions, perhaps anyone can aswer? Say that i have a closed can with pressurised water lying in a pool of water. My question would be what the best method would be for...

As part of a racing community, there is a discussion going on that talks about compressibility of brake fluid. the Street car versions have a value of 6.5E-05 and the racing stuff is 4.5E-05 both at a pressure of near 5000psi. there is talk about the difference of the racing fluids which...

Homework Statement I have a confusion regarding areas. Usually in fluid flow I am using the A=(pi*D^2)/4 However in heat transfer we usually use A=pi*D*L Could you please explain this?I mean in first case(fluid flow) it is cross sectional area and in the 2nd case(heat transfer) is like the...

1. Homework Statement See image. Homework Equations I thought that Fx=p*u1*A1(u1+u2)+(p1*a1)+(p2*a2) would be the correct formula however I cannot seem to get the stated answer of 1.8kN. The Attempt at a Solution Using the above formula, p1v1=p2v2 to find u2 and p1a1=p2a2 to find p2...

Hello, i am new at the forum and i hope i can help and get helped so we can move forward in our projects/jobs/studies. I also ask please to correct any gramatical or vocabulary mistake, since i am still learning english. Now to the actual problem. I am already building some kind of epoxy resin...

So I recently looked into the venturi effect, only to be confused. I had always been aware that a lower available volume would result in a higher pressure, yet I had read that fluid passing through a constriction is actually subjected to less pressure than the diverging sides of a pipe. I had...

Homework Statement A water bottle has a tap tube at the bottom. The diameter of the valve opening is 1 cm. If you turn on the tap, the water drains out with a velocity of 1.4 m / s. If the air pressure in the bottle is equal to the atmospheric pressure outside it, how high the water than in the...

Homework Statement Hello, I am struggling with this heat transfer and fluid flow problem.I would really appreciate if someone could have a look over what I have done on it. I am not sure if what I have done is correct ,I would really appreciate if you could tell me if it is correct or wrong.And...

Homework Statement Through a (cylindrical) heating tube, warm air has to flow with a velocity of 3m/s in order to heat a rectangular spacewhich is 12 m long, 10 m wide and 2.5 m high. How large the radius of the tube should be if the air in the room get refreshed every 15 minutes ? Assume that...

Homework Statement I would really appreciate if someone could help me out with this exercise in fluid flow/heat transfer ,because I really struggling with it.Below I am attaching photo of problem+table with values. Thank you in advance !Homework Equations Question link:[/B]...

Hello everybody, It is normally said that fluid flow in a larger diameter pipe is easier (less energy losses) than in a smaller diameter pipe. This indeed appears to be true in relatively high flowrate applications however, I'm struggling to understand why drinking from a normal straw (small...

Homework Statement Homework Equations Fluid in rotation The Attempt at a Solution This exercise is quite different from the classic one of fluidi in rotation. Before rotation starts the height in one branch is bigger than in the other, so I do not really know how to approach the problem...

Hello! Please help me understand whether I'm going to the right direction with the solution or partially wrong or completely wrong. I have a basic Fluid Mechanics course at the uni, the following problem is from a past exam my teacher gave us to practice before the exam, so there're no answers...

Homework Statement The tank in picture has section ##S_1## and it's linked with a tube of section ##S_2=\frac{1}{\sqrt{17}} S_1##. The tank is filled at an height ##h## and this level is kept constant by a sink ##R##, in such way that the exiting volumetric flow rate is ##Q=0.3 m^3/s## and...

Homework Statement Consider the truncated cone tank submerged in water: inside the truncated cone tank there is air. Evaluate the forces acting on the truncated cone tank. Homework EquationsThe Attempt at a Solution The forces are the following Boyuant force : $$F_b= \rho_w g V_{tank}$$...

I wonder if it is correct to read an open air manometer in the case of viscous fluid in the following (usual) way. Consider the situation showed in the picture where a viscous fluid is flowing, in fact ##z_C <z_A##. The reading of the manometer would be ##p_a=\rho g z_a##, ##p_b=\rho g z_b##...

Hello, I've search for a while on these threads, and its difficult to find the answers that I'm looking for. I know perpetual energy machines are banned from topic, but closely related is the idea of free energy. Is free energy (or close to it) allowed to be a topic of conversation? Why not if...

So i have this Diesel Water pump, i need to achive a pressure of 4 bars at the end of the hose, How to calculate the pressure in inlet to achieve the desired result of 4 bars at outlet. (Assuming that I'm using a standard hose of length 30metres, with a diameter of 2.5 inches) Pump FLOW RATE IS...

Hi, I am working on the laminar flow and during my calculation at the outlet of my nozzle my Re was even greater than 120,000 however my other calculations seemed legit to me. And someone told me that I am calculating the Reynolds number of an open channel and for that flow can remain in laminar...

Homework Statement For a system of discrete point particles the energy momentum takes the form T_{\mu \nu} = \sum_a \frac{p_\mu^{(a)}p_\nu^{(a)}}{p^{0(a)}} \delta^{(3)}(\vec{x}-\vec{x}^{(a)}), where the index a labels the different particles. Show that, for a dense collection of particles...

I am trying to learn how hydrofoil works. A big part of it is Bernoulli's principles. I found this http://web.mit.edu/2.972/www/reports/hydrofoil/hydrofoil.html on MIT webisite. There are two explanation for how it works: 1. The conservation of linear momentum or Newton's third law.If water...

Homework Statement i know that the ratio of length of prototype divided by the length of model would yield Lr But , some book gave that length of model divided by length of prototype also= Lr ?Homework EquationsThe Attempt at a Solution Which is correct ?

is there any difference and why ? I have a ball valve with 100 psi jet fuel on one side and atmosphere on the other end ? Is there any difference if o have 100 psi and the valve all the way open vs. say 200 psi and only half way open . Please explain ?

Homework Statement [ For a system of discrete point particles the energy momentum takes the form T_{\mu \nu} = \sum_a \frac{p_\mu^{(a)}p_\nu^{(a)}}{p^{0(a)}} \delta^{(3)}(\vec{x}-\vec{x}^{(a)}), where the index a labels the different particles. Show that, for a dense collection of particles...

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...

Partial pressure must be less than or equal to the vapor pressure if there is no liquid present. However, when both vapor and liquid are present and the system is in the phase equilibrium, the partial pressure of the vapor must be equal to the vapor pressure and system is said to be saturated...

Homework Statement A hot oil(specific gravity = 0.7) flows through a pipe of 4 cm internal diameter, at a velocity of 0.2 m/s. Determine:i) The volumetric flow rate of the oil discharged from the pipe. ii) The mass flow rate of the oil discharged from the pipe. iii) If the pipe discharges the...

Homework Statement A well-fitting piston with 4 small holes in a sealed water-filled cylinder,shown in Fig is pushed to the right at a constant speed of 4 mm /s while the pressure in the right compartment remains constant at 50 kPa gage. Disregarding the frictional effects,determine the force...

Homework Statement I know that when the fluid flow from pipe to reservoir, the coefficient of discahrge is 1, where head loss =k(v^2)/2g... How about the fluid is discharged from pipe to atmosphere?? Homework EquationsThe Attempt at a Solution

Hello here is a schematic of the problem: http://imgur.com/CgcybVT A stream of helium gas will be used to carry aerosolized particles. I am assuming conservation of mass (and mass flow) The mission is to find the exit stream velocity of the gas. For the time being, i am assuming the weight...

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...

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...

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...