The engineering tag has no wiki summary.
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16 views
Why is Erbium Doped Fiber Amplifier (EDFA) preferred over Erbium Doped Waveguide Amplifier (EDWA)?
Why is Erbium Doped Fiber Amplifier (EDFA) preferred over Erbium Doped Waveguide Amplifier (EDWA)?
The question has been asked from an engineering point of view, but obviously I would also be ...
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0answers
21 views
The stress in copper and steel parallel compound members [closed]
Came across this question and just needed abit of help undertanding how i should go about this question
I have also attempted to solve it to the best of my ability but im stuck.
A concrete column of ...
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1answer
112 views
Why do wind power plants have just 3 blades? [duplicate]
Why do wind power plants have just 3 blades? It seems that adding more blades would increase the area that interacts with the wind and gather more energy.
(Image from Wikipedia.)
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1answer
161 views
Compressible fluid flow through a branched pipe junctions
Backdrop: Designing a dust extraction system (LEV) with a branched junction.
What principles allow for the calculation of volume flow rate and pressure at the inlets if the volume flow rate and ...
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2answers
187 views
Fluid flow through a diverging pipe
Relevant diagram loosely based on my real problem:
Description of problem: A fan creates a pressure sink that drives fluid flow through a gently diverging pipe (please note that the diagram is not ...
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3answers
3k views
Yield Strength versus Ultimate Strength
What is the qualitative difference between these two:
As seen on the table Typical yield and ultimate strengths.
I am trying to resolve the meaning of the phrase "contact yield stress" from C. ...
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3answers
180 views
Why are precise frequency standards important in the telecommunications industry? [closed]
I understand why having a precise definition of time can be very useful for navigation purposes. The GPS system works using the simple equation $d=ct$, where $c$ is the speed of light, so the ...
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1answer
49 views
Measuring vibration and converting to force (N)
The test is:
To have a rotating machine, bolted into a factory floor.
To measure the vibration on 3 axis (output of accelerometers can be acceleration or velocity in $\mathrm{m/s}$ or ...
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1answer
90 views
Shear Flow corresponding to Eccentric Shear Force of a Closed-section Beam (Structural Analysis - Mechanics)
Been stumped with this question for way too long... its a beam with a thin-walled rectangular cross-section, and a shear force is acting at a distance from the shear center. I know my decomposition of ...
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1answer
34 views
What lifting mechanism is likely to have the best energy recovery ratio?
Suppose I was designing an apparatus which needed to lift 250kg 5cm high, hold it there for a few seconds, and then lower the object back to the original height. Such a process would need to be ...
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0answers
79 views
How to calculate mechanical advantage of a worm gear?
How to calculate mechanical advantage of a worm gear?
My textbook simply use the turn ratio as the mechanical advantage, but I'm not sure how that works.
My thinking: If the worm has a radius of ...
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3answers
1k views
Could a real-life X-Wing fly in Earth's atmosphere?
From an aerodynamic point of view, could a full-size aircraft of X-Wing design fly in Earth's atmosphere? Assuming you were free to add control surfaces here and there, could the wings in open ...
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1answer
59 views
Amount of energy to separate Gases - relationship to concentration
I want to understand the efficiencies of separating mixed gases, and for that I want to understand the thermodynamic limit case. Looking at the wikipedia page for entropy of mixing, I find the ...
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2answers
155 views
What properties would the ideal material for spacecraft construction possess?
Assuming we develop the capability to send a robot to study Gliese 518, or any of the Earth-like planets discovered in the neighbourhood; the spacecraft would need to travel through the Solar System ...
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0answers
92 views
Why did increasing the Ackermann geometry in my race car make it faster in corners?
Ackermann geometry is used to account for the different radius arcs that the front tires follow when the steering wheel is turned from center. It's often expressed as a percentage: e.g. 25% Ackermann, ...
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4answers
757 views
Are quantum mechanics calculations useful for engineering?
I heard it's is pretty tough to get results for more than a few quantum particles. Are quantum mechanical calculations useful at all for any technology that is being sold?
Or do they use ...
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1answer
449 views
Air Turbulence and DIY laminar flow hoods
So for years on the mycology, plant tissue culture, and DIY laboratory websites there has been this ongoing debate on how to achieve laminar flow in a home built laminar flow hood.
Flow hood link!
...
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4answers
318 views
What is a strain gauge and how do I use one?
As the title says, I have no idea what these things are or how to get or use one. Can I receive a simple explanation or links to one? I'm a computer engineer so I have very little physics/mechanical ...
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0answers
91 views
Internal moment in the hull of a pressure vessel
This question is related to the course structural analysis. As part of our exam grade every student has been given different multiple homework assignments which we have to solve.
One of the problems ...
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1answer
41 views
Optical refocusing efficiency
What is the material for optical focusing that produces the less diffraction losses?
Suppose one have a sequence of serial optical elements $R$ that keep refocusing a beam of collimated light, each a ...
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2answers
2k views
The most efficient Fan Blade Design
What could be the most efficient fan blade design? There are three main factors for a good fan: one is speed at which air is circulated; second,the volume of air it can circulate; and the third is ...
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1answer
262 views
Internal forces in a truss and its geometry
I'm to work out the internal forces in a truss, but I can't get my head around the geometry of the truss itself. I'm starting to think there may have been information on the diagram which I missed. ...
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1answer
183 views
How to estimate the Kolmogorov length scale
My understanding of Kolmogorov scales doesn't really go beyond this poem:
Big whirls have little whirls that feed on their velocity, and little whirls have lesser whirls and so on to viscosity. ...
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2answers
170 views
Can someone explain the Hall effect thruster to me?
I am in high school, and am doing a major research project on Russia. Part of that is a section on the space race, and ion engines/hall effect engines have come up several times. Unfortunately, Google ...
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0answers
31 views
Does graphene actually remain strong for macroworld engineering?
I heard that people envision strong structural materials made out of graphene, but I heard it may weaken when being stack in layers. Is graphene viable for macroworld structural engineering or is it ...
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2answers
141 views
Total Mechanical Advantage
How do you find the net Mechanical Advantage (MA) of two joint machines. Do you add or multiply the individual MA?
Suppose I have two sets of wheel and axle connected by a fixed pulley. Each of the ...
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0answers
196 views
Torque required to rotate Drum [closed]
What Torque will require to rotate a Drum about horizontal axis XX.
Drum is filled with industrial Oil.
Weight of filled drum is $W=300 kg$.
Length of Drum $(L)=900mm$
and Diameter of Drum is ...
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0answers
33 views
Twist angle for Valve
I have to design a gearbox to operate a ball valve. The gearbox output shaft has to design on the basis of torsional rigidity. What angle should be considered for twist angle ?? and why ??
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140 views
Torque required to rotate sand mixer [closed]
the given data is-
Mixer having one impeller(rotor) rotating in horizontal plane about vertical axis.
capacity of mixer to design $C = 250kg$
rotor dia. $D = 45" = 1143mm$
friction coefficient ...
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3answers
180 views
How to determine whether a large container is air-tight?
In constructing a kitchen-waste digester at home, I use a 50 Litre HDPE drum. The base of the drum is holed with a plug fitted to allow drainage when necessary.
The top has two openings - one for ...
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3answers
510 views
Statics software for structural engineering
I'm attempting to expand my knowledge of engineering software. I've found comsol and ansys for acoustics and thermodynamics/fluid dynamics (not necessarily in that order), now I'd like to see if I can ...
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4answers
781 views
Is the EmDrive, or “Relativity Drive” possible?
In 2006, New Scientist magazine published an article titled Relativity drive: The end of wings and wheels1 [1] about the EmDrive [Wikipedia] which stirred up a fair degree of controversy and some ...
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1answer
92 views
How to interpret a negative failure rate?
In statistical engineering the "hazard rate" of a distribution is defined as:
$$r(x)=\frac{f(x)}{1-F(x)}$$
where $f(x)$ and $F(x)$ are the PDF and CDF. Basically $r(x)$ is the odds that, having ...
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2answers
132 views
Why aren't stratospheric balloons compressing their helium to descent?
I can't find a reference of a working stratospheric balloon mounted with a compressor to control its altitude. Is there a big physical difficulty (such as compressor weight/power ratio, or power ...
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2answers
109 views
Would it be possible for geophysicists/geoengineers to develop an artificial way of trapping carbon in the ocean?
There's a mechanism by which the southern ocean sequesters carbon from the atmosphere. It happens when strong winds displace a large slab of surface water, accumulating in a specific region where the ...
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3answers
5k views
What is the difference between a moment and a couple?
In mechanical engineering, the torque due to a couple is given by $\tau = P\times d$, where $\tau$ is the resulting couple, $P~$ is one of the force vectors in the couple and $d$ is the arm of the ...
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0answers
298 views
propeller flying physics for the layman
I'm starting a (quad?)copter build, and i can find plenty of knowledge about stabilizing the craft and things related to gyroscopy.
but there's absolutely zero information on things that help me ...
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33 views
Which are some insects showing most impressive feats of engineering? [closed]
Would prefer one or two examples with lots of in-depth info.
Examine it from an engineering point of view.
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3answers
245 views
Can anyone estimate what proportion of water remains after I flush a toilet?
Imagine I have a clean toilet with some amount of water in the bowl. When I flush the toilet much of that water will be displaced by the tank's water. I want to work out (or model really) what amount ...
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1answer
175 views
I want to recreate a phenomenon I've noticed from our water tank
I'm trying to recreate a phenomenon I have noticed from our water tank at home. Ok so we have a deep well pump that fills our water tank everyday. But something odd always happen everytime the water ...
4
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2answers
1k views
Shape of Fan Blades
How is the shape of the blades of an air fan determined? Trial and error, or is there a theory behind it? What are they trying to maximize, volume of air dislocated per rotation?
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2answers
560 views
Calculate the weight a simple plank can support
I'd like to build a simple desk; just a single plank of wood (or a few side-by-side) with solid supports on each end of the desk. What I'm trying to figure out is how thick a plank I want to use for ...
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2answers
742 views
Calculation of the maximum load to the bar
Looking for a way of calculating the maximum weight (W) to the rod with the given length (L) where the rod did not break and that only bend for (b) mm.
Need only approximative solution (read: ...
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2answers
888 views
Angles on swing sets
I'm building a swing set for my children. All of the designs I've seen involve building two A-frames and connecting them at the top with a crossbar/beam from which hang the swings. The A-frames are ...
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3answers
142 views
Do processes $P\propto\frac{1}{V^2}$, $P\propto\frac{1}{V^3}$, $P\propto\frac{1}{V^4}$, etc., exist in the real world?
Is there any real process in which $PV^n=C$ where $P,V$ stands for pressure, volume respectively. $C$ is a constant and $n$ is a positive integer?
I am familiar with Boyle's law that states that ...
4
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1answer
399 views
A conceptual problem with Euler-Bernoulli beam theory and Euler buckling
Euler-Bernoulli beam theory states that in static conditions the deflection $w(x)$ of a beam relative to its axis $x$ satisfies
$$EI\frac{\partial^4}{\partial x^4}w(x)=q(x)\ \ \ \ (1)$$
where $E$ is ...
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64 views
How is pool boiling dealt with by today's process design methods?
Designing evaporators and industrial reboilers often requires at initial stages of dimensioning (i.e. when the support from a finite element software tool to model the system of interest, isn't yet ...
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3answers
198 views
How does the shape (form; not cross-section) of a spring impact performance?
Cylindrical compression springs are everywhere and then some applications choose other forms like rectangular or unique polygonal form. What impact does the form of a compression spring have and how ...
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3answers
375 views
Can I study Quantum Computing or Quantum Mechanics with an Engineering background?
Sir,
I am studying Electrical & Elctronics Engg. now. I wish to pursue Quantum Mechanics or Quantum Computing as my research subject. Is it possible for me to do my M.Tech. & then pursue ...
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2answers
6k views
Hollow Tube Stronger than Solid bar of same Outside Diameter (O.D.)?
I was listening to some co-workers talking about problems meeting stiffness requirements. Someone said that even with a solid metal rod (instead of the existing tube) we could not meet stiffness ...
