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1500 questions
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How do gas flow regulators avoid choking?
According to compressible flow theory, a downstream pressure of 0.528 times upstream pressure is sufficient to choke a flow device.
So, how do industrial grade pressure regulators throttle a wide range of pressures (say 150 bar to 20 bar)?
DBTKNL
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5
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A stable transfer function which diverges?
This question might sound stupid as I'm more of a software guy and never really had to do control engineering (besides the 101 classes).
So I have a second order system I could approximate, with the following denominator:
$$s^2 + a_1s + a_0$$
Both…
lesurp
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5
votes
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Silicon and silicones
Why Silicon can be used in many engineering materials like oil (Silicone oil), grease, caulk, rubber(PDMS), resin? What property of Silicon allows so?
RTh
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5
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Why is capacitor 2 not grounded on this board?
I'm building a APRS tracker for a high altitude balloon and am tracing the voltage as it's not powering up. I'm confused why it seems that this capacitor's ground appears to not be connected to anything. topside of board
Jim Swarthout
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3 answers
Turbocompressor spool geometry
How come axial compressors always narrow and turbines always widen towards the rear? From what I know:
The speed of sound of air increases with temperature, therefore increases (decreases) as it goes through the compressor (turbine).
The compressor…
setun-90
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5
votes
2 answers
How can I tell if a motor is defective?
I recently bought two 12 V DC motors from Amazon. After I received them today, I tried testing them. One of the two motors run fine but the other motor shows erratic behaviour. It gets very hot within 10-15 seconds of running, and then stops. It…
YaddyVirus
5
votes
3 answers
Snap fit on an enclosure
I am designing an enclosure, and top and bottom should be linked thanks to snap fit. I have to use 3D-printing to make both parts. The material is ABS. I made some trials, but they keep breaking. I am using the design in the following picture. Do…
Mathilde
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Seeing through walls and noninvasive structural integrity metrics
Walking into a building, how does one find out where the pipes are, how strong the walls are (currently) and other key structural integrity measures?
without breaking walls or utilising harmful-to-human emmissions (e.g.: strong x-rays)
Some ideas I…
A T
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1 answer
Can the thickness of a guard post be derived purely from energy principles?
Consider an ordinary staircase with a banister rail supported by a wall at one end and a steel post of constant profile at the other end. The base of the post is embedded rigidly in the fabric of whatever structure the stairs are part of. The post…
Stilez
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Do all ductile materials experience necking before fracture?
This stress-strain curve presents a linear elastic range, followed by yielding and accompanied by a decrease in toughness the material goes into the plastic region. As it strains more and more the material then suddenly snaps! Without necking...…
user6462
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5
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2 answers
what is a quarter wave decay response after Ziegler–Nichols tuning?
Ziegler–Nichols tuning creates a "quarter wave decay". What does that mean? I cannot find anything online!
ergon
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5
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1 answer
PI-Controler: Comparison of characteristic equations
I have to design a PI-controller with zero order hold for the plant
$G_s(s) = \frac{0.24}{(s+4)(s+12)}$ to meet the specifications of $\omega_n=5\,s^{-1}$ and $\zeta = 0.6$.
I choose a $T=0.12\,s$ which leads to a approx. 13 samples per oscillation…
Lageos
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5
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2 answers
One way plastic rubber pipe
I am working on a project for college, and I am stuck on one idea that I don't really know how to represent it.
Basically what I want to do is something like a pipe, that if a put a kind of cylinder on inside from the top side, the cylinder will…
peterpeterson
- 153
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5
votes
1 answer
Aluminum vs Steel rivets/fasteners in a high vibration environment
What are the relative pros and cons between aluminum and steel fasteners when riveting together sheet aluminum (50XX or 60XX) when high amounts of vibration are anticipated? Assuming that the usual guidelines for sheet thickness, hole size and…
Green
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Generating a Blank Seismic Tripartite Graph
I am performing a calculation in which I need to plot a generated response spectrum to a seismic tripartite graph. However, I am having a heck of a time finding a blank tripartite graph online. A low-resolution example is shown below.
How might I…
grfrazee
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