What is Fluid mechanics: Definition and 756 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.
I'm not sure if I should have posted in the advanced section, but this is for the class "fluid mechanics" which is an upper division course. However, the material I'm asking is mainly introductory stuff.
Determine the dimensions of dP/dx.
Where P is a force and x represents distance
So...
Homework Statement
Homework Equations
I am having some trouble starting this problem. At first look I would say that a conservation of mass will give V1*A1=V2*A2 for steady state incompressible fluid. Then I would solve for A2 and relate the two diameters but I don't have the velocity...
Hi folks I am currently doing a question in fluid mechanics and i need some help rearranging formula to solve the equation... I have everyhting i just can't seem to figure how to make u( Velocity) the subject of the equation...
The equation is μ = Fx/uA
Thanks in advance
Eddie
A liquid atomizer has the configuration shown in Figure Q5(http://img822.imageshack.us/img822/8543/figure5.png ). The liquid is accelerated through the nozzle and impinges on a cone attached to the nozzle by a thin rod. The nozzle is circular in cross-section and coaxial with the rod and cone...
Suppose I have say a 40' long 3/4" garden hose stretched out linearly on a level surface. One end is attached to a faucet with maybe 30 psi. At 10', 20', 30', and 40' there are small vertical pipes from which will shoot water when the faucet is turned on. The end of the hose is capped. There's...
Homework Statement
Consider the steady flow of an incompressible viscous fluid down an inclined plane under the action of gravity. The plane makes an angle \alpha with the horizontal. The fluid is infinite in the z-direction (x is down the plane and y is normal to the plane). Look for a...
Homework Statement
The drag force F on a car depends upon its speed V, length L, the density ρ of the air
and the dynamic viscosity of the air µ . Show that this statement regarding five
physical quantities can be re-written in terms of two independent non-dimensional
groups...
Homework Statement
Spanish galleon is about to be boarded by bloodthirsty pirates in the
shallows of a Caribbean island. To save a box of treasure on board, the
captain orders his crew to secretly toss the box overboard, planning to come
back for it later. The rectangular box is waterproof and...
I am working on a project at an internship this summer regarding flow rates of a certain system that is used to test flow rates on tools, and it requires a bit of a hefty explanation.
I need to increase the current flow rate (1232 GPM) to the desired flow rate (1800 GPM) because some of the...
I am goin to study fluids mechanic next year, and I want to prepare for it, so I found the cours that corresponds to it, it is translated to english nd linked below. anyway, I want to know or if somebody can lead me to math courses that it is related to fluid mechanics, coz I need to learn it...
I have a question based on this little diagram I whipped up!
http://i.imgur.com/2sLeQ.jpg
Will the 25 PSI (generated by a pump) applied to the curved surface on the bottom of the piston exert a higher force upwards to oppose the downward force on top of the piston?
A detailed...
Homework Statement
Homework Equations
Provided above
The Attempt at a Solution
Piezometric head is defined as the pressure head plus the elevation head, correct? But how does having a high piezometric head tell you about the fluid flow?
Since the diameters are equal, the area's are...
A jet of water 70mm in diameter moving with a velocity of 25m/s impinges tangentially on a stationary blade which deflects the jet through 130o.
(a) Find the resultant force on the blade, in magnitude and direction.
(b) If the blade has a velocity of 5m/s in the same direction as the jet and...
Homework Statement
You are given a 10cm Cube of aluminum with Density of 2700kg/m is submerged in water and the weight in water is 13N. If a cavity exist how big is it?
Homework Equations
The equation i used were B = V * P_water * g to find buoyancy.
To find the enclosed cavities i...
Hi
First off I'm not a student, this is purely a curiosity question
In pascals law classic drawing if you added a piston inside one of the cylinders what would happen?
I've added a drawing to clarify
I'm totally split on what the answer is, Pascals law seems to state the pressure on...
I know the main focus of Civil Engineers are the strength of the structures. I also know that Fluid Mechanics and Hydraulics are important in designing dams or other structures related to fluid. But what about to Building structures? How is it important?
The following question is on viscosity, and I feel like I am looking too much into the problem, but I am having a very hard time getting started!
The total space between stationary boundaries is 1cm. Ethylene glycol is placed on the left side, and propylene glycol is placed on the right...
Homework Statement
A horizontal bend in a pipeline conveys water at a discharge at 1000l/s gradually reduces from 600mm to 300mm and deflects the flow through an angle of 60 degrees. At the larger end the pressure is 170000N/m^2. Determine the magnitude and direction of the force exerted on...
Homework Statement
If in an open water channel, the approach speed of an incompressible ideal fluid, of constant depth h1, is not too large, a small bump in height H (H<< h1) in the base of the channel will cause a dip Δh (Δh << H) in the water level directly above it, such that h1 = Δh + H...
The problem: A canal cut in rock (n= 0.030) is a trapezoidal in section with a bottom width of 6.10m and the side slopes of 1 on 1. The allowable average velocity is 0.76 m/s. What slope will produce 5.66 m^3/s? The books answer is 0.000675
from the mannings equation
V=(1.486/n)R^2/3 x...
Hi, i am having difficulty with a question because i cannot seem to get the right answer. i don't think i am far off i just know i go wrong somwhere and if you could point that out it would be great. the question is attatched. for the first part i find the equations of the lines of the two sides...
I'm taking fluid mechanics in the fall, and I hear the professor is a real pain. I want to prepare over the summer by getting exposure to the material.
I'm in an undergraduate program, and have all the math I need (though it's been a while since differential equations, so I'm actually...
Homework Statement
Given: water at 20°C flows through a 3cmID smooth brass tube at 0.002 m^3/s.
Homework Equations
V=Q/A
f=64/Re
Re=VD/(nu)
The Attempt at a Solution
V=Q/A=(0.002 m^3/s)/((∏/4)*(0.03 m)^2) = 2.829 m/s
Re=VD/(nu)
= (2.829 m/s)*(0.03 m)/(1x10^-6 m^2/s)=84882.64...
I'm having a little problem with my book as I was reading about fluid mechanics. The book seems to have skipped a bit of some crucial part (at least for me) during the derivation for fluid pressure at certain depths (where the weight of the fluid is not neglected).
Here, I'll try to reconstruct...
Fluid Mechanics Question -- Pipes and Pumps
Homework Statement
Design a system to deliver 1 m^{3}/s of water from reservoir A at elevation 300m to reservoir B at 500m. The distance from A to B is 1000km (1000,000m) and the elevation between the two reservoirs can be approximated as...
Hi all,
Sorry if this topic has been done a lot. I'm not very good at searching.
It seems to me that fluid mechanics is left to engineers and mathematicians (in particular, applied mathematicians? I guess they study the concept of flow?)
What gives? Engineering department here at Cornell has...
Homework Statement
A can of Coca‐Cola has a small pinhole leak in it. The Coke sprays vertically
into the air at a height of 0.5 m. What is the pressure inside the can?
ρ = 1.11 g/mL
Homework Equations
Bernoulli: p1/ρ + (v1^2)/2 +g*z1 = p2/ρ + (v2^2)/2 +g*z2The Attempt at a Solution
I've...
When I am reading the paper in fluid mechanics, I found a paragraph and two equations:
"Since the fluid is considered Newtonian and incompress-
ible of density ρ and constant viscosity μ, the dimensionless
mass and momentum balance equations are:"
\nabla \cdot \mathbf{v} = 0...
Homework Statement
The problem:
There is an illustration and the question is to find the force F to lift a concrete block gate if the the concrete weighs 160 lb/ft3. The block is 3' in diameter and 1' thick. It is in a tank of fresh water 15 ft down. the specific weight of the fresh water...
I'm in first-year physics classes and we just wrapped up our solitary chapter on fluid mechanics, which covered the very basics (pressure, Archimedes' Principle, and Bernoulli's equation). I find this more interesting that the classical mechanics we've been doing up till now, so I was wondering...
Homework Statement
A long water trough of triangular cross section is formed from two planks as is show in Fig P3.66. A gap of 0.1 in. remains at the junction of the two planks. If the water depth initially was 2 ft, how long a time does it take for the water depth to reduce to 1 ft...
Continuum approximation of fluid mechanics (& relativistic fluids)
I have a few 'foundational' questions on fluid mechanics which I haven't been able to find quick answers to, any help would be appreciated.
At the start of any course on fluids, one is told of the continuum hypothesis...
Hollow spherical ball with inner and outer radius R and r respectfully is made of a material with density 1. The ball is swimming in a liquid with density 2. How much should be the density of the substance that will fill the hollow ball so that it can float?
help pls
Homework Statement *See attachment for diagram*
With steady-state operation, an energy balance between point 1 and point 2 along the A side dictates:
*See attachment for equation 1*
And an energy balance between points 1 and 2 along the B side dictates:
*see attachment for equation 2*...
Homework Statement
Calculate the density in lbm/ft3 with the given formula: ρ=p/RT where p=35 psi, R=1716 ft-lbf/slug-°R, and T=100°F.
We have access to a table with basically any unit conversion we would need.
The Attempt at a Solution
100°F=37.78°C=310.9278K
(35 lb/in2)(144 in2/1...
Watch this video first, please. ( http://www.youtube.com/watch?v=2ghBUcQG1lQ&feature=related ).
I had been imagining magnetism in general as fluid motion and not like it is portrayed now days for the last few years. Disregarding the hundreds of notes and all that, what I did notice was this...
A metal cube is placed in an empty vessel. When water is filled in the vessel so that the cube is completely immersed in the water, the force on the bottom of the vessel in contact with the cube :
Ans: Will remain the same.
But how? Won't the force exerted in the second case,i.e when the...
A metal cube is placed in an empty vessel. When water is filled in the vessel so that the cube is completely immersed in the water, the force on the bottom of the vessel in contact with the cube :
Ans: Will remain the same.
But how? Won't object exert an extra force which will be...
Hi
Recently performed a very basic fluid mechanics experiment with water flowing at different speeds through a Venturi Rig. Most of it went as expected, total head stayed roughly the same throughout but slightly decreased from flow loss due to resistant forces.
However, at certain random...
Homework Statement
Calculate the pressure drag cofficient for a cylinder using the trapezoidal and simpson's rule (assume the flow is the same on both sides of the cylinder).
Angle (deg) Cp
0 1
30 0.274
60 -1.565
90...
Homework Statement
In a very large closed tank, the absolute pressure of the air above the water is 6.01x10^5 Pa. The water leaves the bottom of the tank through a nozzle that is directed straight upward. The opening of the nozzle is 4.00m below the surface of the water. a) Find the speed at...
Homework Statement
The pipe shown has a 180° horizontal bend in it as shown, and D is 20 cm. The
discharge of water (ρ = 1000 kg/m3)in the pipe and bend is 0.30 m3/s, and the
pressure in the pipe and bend is 100 kPa gage. If the bend volume is 0.10 m3 and
the bend itself weighs 500 N...
Ive found Fluids and Heat Transfer stuff to be difficult so far in my learning. I, for some reason, can't put everything together and feel like there is just this overwhelming abundance of equations that you need to know how to manipulate to get what is asked. My issue is that I don't know...
Hello!
I'm a biomedical engineer student and I'm working on a project about the fluid dynamics in artificial hearts.
What I want is to compare the fluid dynamics in real hearts and artificial ones, have a general idea on what problems can arise when trying to produce an artificial heart...
Homework Statement
A large barge of overall width 4m to be used at sea has a uniform empty weight per meter length of M=6327.19kg/m (length is into the page). This empty weight is uniformly distributed along the length of the barge. The center of gravity of the empty barge is at position G...
This one is actually for a lab assignment. In the experiment you shoot a jet of water upward vertically at a variety of targets with different geometries (a flat plate, various cups). The target is suspended from a rod, and on top of the rod is a cup where you can add weights, held up by a...
Homework Statement
I need to find the net force acting on a flat squared roof with area A while the wind is blowing outside at some velocity, v_1.
Homework Equations
Bernoulli's Equation:
P_1+\frac{1}{2}\rho v_1^2+\rho gy_1= P_2+\frac{1}{2}\rho v_2^2+\rho gy_2
The Attempt at a...