What is Fluid mechanics: Definition and 755 Discussions
Fluid mechanics is the branch of physics concerned with the mechanics of fluids (liquids, gases, and plasmas) and the forces on them.:3
It has applications in a wide range of disciplines, including mechanical, civil, chemical and biomedical engineering, geophysics, oceanography, meteorology, astrophysics, and biology.
It can be divided into fluid statics, the study of fluids at rest; and fluid dynamics, the study of the effect of forces on fluid motion.:3
It is a branch of continuum mechanics, a subject which models matter without using the information that it is made out of atoms; that is, it models matter from a macroscopic viewpoint rather than from microscopic. Fluid mechanics, especially fluid dynamics, is an active field of research, typically mathematically complex. Many problems are partly or wholly unsolved and are best addressed by numerical methods, typically using computers. A modern discipline, called computational fluid dynamics (CFD), is devoted to this approach. Particle image velocimetry, an experimental method for visualizing and analyzing fluid flow, also takes advantage of the highly visual nature of fluid flow.
Here is the problem i am trying to solve;
A power-law fluid has a density of 1075 kg/m3. It is pumped at a rate of 2500 kg/hour through a pipe of internal diameter 25 mm.The flow is laminar and the power law constants are K2 = 3 Pa.s^n and n = 0.5. Estimate the pressure drop over a 10 m...
Homework Statement
[PLAIN]http://img30.imageshack.us/img30/6918/screenshot20110828at111.png
Homework Equations
P_base= rho * h * g = 1800 kg/m^3 * h * 9.81 m/s^2 = 17658 * h kg/(m^2 s^2)
F_h= .5 * h * P_base = 10594.8 * h^2 kg/(m^2 s^2)The Attempt at a Solution
I am trying to find the force...
Homework Statement
I am trying to calculate y in the relation y+=(ut*y)/v where y+ is similar to a local Reynolds number, so its magnitude can be expected to determine the relative importance of viscous and turbulent processes. In the listed relation ut is the friction velocity [ut=sqrt(wall...
Hi guys.
I have a question on sonic pressure wave behavior in pipes.
When a pressure wave traversing down a pipe encounters a change in cross-section, namely, a convergence say like that of an expansion chamber, a negative pressure wave is reflected back in the opposite direction. My...
Hi friends - I'm at a lost on this particular problem which reads:
a manometer consists of a U-tube, 7mm internal diameter, with vertical limbs with an enlarged upper end of 44mm diameter. the left-hand limb and the bottom of the tube are filled with water and the top of the right hand limb...
I'm a Mechanical Engineering major and am starting Fluid Mechanics this semester. My professor suggested Fox's book, as he's going to take most problems from that book, though I've heard this book is really weak and I would like to buy something that I could dig further into the subject...
I don't understand why stream tubes exist. Stream tube is defined here: http://www.princeton.edu/~asmits/Bicycle_web/streamline.html
Why can't you have a stream line starting at a point going one way, and then the stream line at the neighboring point going some orthogonal direction, and thus...
Hi!
Im a student in chemical engineering and I would like some recommendation for a fluid mechanics book, I've been using Bird's Transport Phenomena but it seems to be a bit difficult to follow it, as it skips a lot of steps.
Hey guys, I'm trying to learn fluid mechanics while at an internship and i just have a quick question. Let's say i have a fluid flowing down and incline plane with a quadratic velocity profile. Which direction does the shear stress (tau) act?
I know the formula for shear stress is tau =...
First of all sorry my english, I'm an italian student
Homework Statement
The velocity field is known
ux=6x+8z*cos(a*t)
uy=3xz*sin(b*t)+2
uz=-6z
The fluid is incompressible.
I need to find the pressure gradient and the i have to determine if it's a turbulent flows, but at the moment i need...
Ethanol of density 791 kgm-3 flows smoothly through a horizontal pipe that tapers in cross-sectional area from A1= 1.20 x 10-3 m2 to A2=A1/2. The pressure difference between the wide and narrow sections of the pipe is 4120 Pa. What is the volume flow rate of the ethanol?
(Ans.: 2.24 x 10-3...
Homework Statement
A model spillway has a flow of 100 L/s per m of width. What is the actual flow for the
prototype spillway if the model scale is 1:20?
Homework Equations
qr = qp/qm
The Attempt at a Solution
My attempt;
qm = 100 L/s per m = 0.1 m^3/s per m
Using the...
Homework Statement
Okay so the question goes like this:
In the design problem to follow, the constants in table 1 may be assumed.
Density P = 1000kg/m^3
Viscosity u = 10^(-3) pas
Gravitational Constant g = 9.8m/s^2
There is a tank in this question. Let's call it Tank 1. I can't put a...
A uniform film of oil 0.13 mm thick separates two circular discs, each 150 mm diameter and
mounted coaxially. Find the torque required to rotate one disc relative to the other at a steady speed
of 400 rev/min if the oil has a viscosity of 0.14 Pa.s. (Ignore edge effects at the rim of the...
Homework Statement
A helium filled balloon is tied to a 2 m long uniform string of mass 0.05 kg.The balloon is spherical
with a radius of 0.4 m. When released it lifts a length h of the string off of the ground. Find the length h given that
the balloon has a mass of 0.25 kg.
Homework...
If an object like a sphere is submerged in a fluid and held in place by a rope, does the pressure are the top and the bottom of the sphere have anything to do with the weight/density/geometery of the sphere? or is it simply a case of using the hydrostatic equation for the pressure at the top and...
Hi,
I am planning to do this as a demo in my fluid mechanics class.
I've used glycerine as corn syrup isn't available. It seems to be transparent and viscous enough. Can anyone please suggest a dye? The video seems to be using coloured corn syrup for flow visualization. How can I...
Well, first of all, thank you for reading this, as you may see this is my first time posting, but I've been reading threads here for a while and found it really helpful, this time I find myself stuck and hope you can push me in the right direction.
Homework Statement
In the laboratory we...
1. Homework Statement
a 2m by 4m window is to be installed under water at a depth of 50 m with seawater on one side and atmospheric pressure on the other. Calculate and plot the distance between the centroid and the centre of pressure starting from when the window is installed at surface...
Homework Statement
a 2m by 4m window is to be installed under water at a depth of 50 m with seawater on one side and atmospheric pressure on the other. Calculate and plot the distance between the centroid and the centre of pressure starting from when the window is installed at surface such...
Fluid mechanics and torque...
Homework Statement
A square gate of size 1m*1m is hinged at its mid point. A fliud of density rho fills the space to the left of the gate. A force F is applied at the bottom of the gate towards right. Find value of F such that the gate is stationary...
Homework Statement
The problem involves fluid flow through a 180 degree bend in a pipe. I am trying to find out the force applied on the flanges connecting the bend to straight pieces of pipe. I am given information on the diameter of the pipe, the length of the pipe, weight flow rate, and...
to construct a barometer,a tube of length 1m is filled completely with mercury and is inverted in a mercury cup.the barometer reading on a particular day is 76cm.suppose a 1m tube is filled with mercury upto 76cm and then closed by a cork.It is inverted in a mercury cup and the cork is...
So I'm most likely studying abroad next semester and taking a Fluid Mechanics course. At my home university, the pre-reqs are multivariable calc, diff eq, statics and dynamics, and classical thermodynamics. Abroad, all I need are multivariable and diff eq.
But I'm worried that I might be at a...
My question pertains to the following article: http://tinyurl.com/4uw9h2a
I have attached the relevant section to this post.
My question is whether Godin's assertion is correct or not - namely the sentence "Such a development ... additional terms" and the last sentence in the attachment...
Homework Statement
A tube of radius 'R' and height 'H' (placed vertically), is filled with a fluid till a height 'h' (<H). Now it is rotated with an angular velocity 'w' about the central axis. Prove that the shape of the free surface is parabolic.
Homework Equations
The Attempt at...
1. A 45 US gallon drum full of water is stored at 4oC. The water temperature is slowly raised to 50oC. What is the change in volume of water over this temperature range as an absolute amount (in Litres) and as a % of the total?
Hello
How would you calculate the total force (due to air pressure) on the top face of a prism, which is partially immersed in water? The top face is horizontal. What formula do you use?
Thank you.
Homework Statement
Not really a homework question, but more of a concept question which I'm unfamiliar with. So as we know, equations can be in any coordinate, but how do you convert them from one to another?
For example, a few equations from fluid mechanics. the first equation is the vector...
Hi
I'm a mechanical engineering student who has been set a question by my fluid mechanics lecturer. I need to plot the velocity flow profile of water flowing in a pipe. The information given in the question is
diameter = 0.5m
Re = 10^5
I know that the seventh power law is used to find...
Homework Statement
Figure 1.1. shows a simplified diagram of the camping stove used by a famous scientist up a mountain, in which gas under pressure is transported to the four nozzles via metal piping. A valve is used to control the flowrate by reducing the delivery pressure to a maximum...
if a tube has area a1 at the left and and pressure P1 and the right has area a2 and is raised to height h ,If the fluid has speed v1 at the left end can i write a1v1=a2v2 and P2=P1+pgh
The question is as follows: A circular tube of radius 'a' bifurcates into two tubes with equal radii 'ka', where k is a dimensionless coefficient. Derive an expression for the ratio of the pressure gradient in each bifurcated tube to that in the initial tube in terms of 'k'.
I'm not sure...
Homework Statement
Homework Equations
P = F/A
The Attempt at a Solution
Hey, recently I started revising fluid mechanics and just going some basic problems. Here I need some help with part (ii)
Well I've calculated the inlet and outlet velocities, converted all units to their...
Fluid Mechanics IMP and URGENT
Can someone please help me solve these questions ASAP thnx
Problem #1
A fluid having a specific gravity of 0.6 and a viscosity of 0.00035 N∙s/m2 flows through a circular duct which is 300 mm in diameter. The average speed of fluid is 15 m/s. The duct is...
Hi,
I am currently doing my masters in mech engineering specializing in fluid mechanics. I am interested in pursuing PhD after my masters. Can anyone suggest the universities which do the best research in fluid mechanics in Europe and US?
I was doing some online physics tests with my friend because we were bored and we both got stuck on this question, I was wondering if anyone might be able to help.
A diver at 50metres under the sea (1.02 density) releases bubbles 1cm^3 in volume. What will the volume be when the bubbles reach...
Homework Statement
The exact problem can be seen in the attached jpeg, and is summarized without figures here:
Homework Equations
Volumetric flow rate: Q = A*V
Continuity equation: (d/dt)*(Integral Of:density*dVolume) + (Integral Of:density*velocity*dA)
Velocity of rain fall down the...
Having trouble using the bernoulli equation to work out the dynamic head for this experiment.
the equation I am using is as follows:
P1/ρg+(v1^2)/2g+z1=P2/ρg+(v2^2)/2g+z2
Where:
P= static pressure
v = fluid velocity
z = vertical elevation of fluid so z1 = z2 for horizontal tube...
I have a centrifuge with hydraulic lines on the arm. I need to calculate the pressure that will be developed at the end of the centrifuge arm in the hydraulic lines.
The radius of the arm is 3 meters. At the end of the arm the G level will be 100g. Obvioulsy the g level at the center point...
Here is the question:
There is a rectangular container with the following dimensions: Length 2 m, Width 1 m, and Height 1m. This container is filled with water to 2/3 of its volume and there is a cover on the top. The cover has a hole in the center.
a) Find the maximum acceleration...
Homework Statement
Please note this is for my own understanding -- I am no longer in school! I simply cannot find this addressed in introductory texts.
Suppose you have a long pipe of constant cross-sectional area with a heated section in the middle. The system has flowing gas such that...
a beaker containing water is placed on the platform of a digital weighing machine. it reads 1100 grams. a metal body of density 8g/cc and mass 200 g is suspended in water in the beaker(without touching the walls of the beaker). it is attached by a suitable string fixed to some support. Now what...
Can anyone recommend books for Fluid Mechanics and Waves.
I don't want a book that requires high amount of maths but a book that strengthens your concepts and thought provoking problems.
Thanks
Homework Statement
water flows steadily with negligible viscious effects through this pipe.
the 4-inch diameter section of the thin walled tubing will collapse if the pressure within is at 6 psi below atmospheric pressure. determine maximum h so that the tube won't collapse.
final...
Hi, I'm an undergrad in biomedical engineering...a required class I'm taking right now is fluid mechanics...this is the textbook we use:
https://www.amazon.com/dp/0470262842/?tag=pfamazon01-20
I'll be frank...I think it sucks...too vague, expects you to fill in a lot between the lines. I...
Why does the air flow faster over the wing? In my fluid mechanics course we used streamlines and a half body to show that the air flow faster over a half circle, but I do not understand why it does so.
Homework Statement
l is an infintesimal material element of length. show that:
Dl/Dt = l dot grad u where l is a smallelement that exists in the velocity field u. Consider its position at time t and t+dt
The Attempt at a Solution
have l(x,t) where x is representing all...