Engineering Stack Exchange
Engineering Stack Exchange

Questions tagged [waves]

26 questions
8
votes
2 answers

Vertical wave action on bridge

Rio de Janeiro, Brazil is currently stunned by the fact that yesterday a span of a brand new (innaugurated in January) bicycle bridge along the coast collapsed when struck by a wave, killing some people that were on it at the time. A few videos have…
Wasabi
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2 answers

What device is this, and how does it work?

There is this device I saw when I was a child at a big music store, that makes me curious. It was meant to listen some CDs to try them out before the purchase. You stand under a bell-shape kind of "speaker" to hear the music, but as soon as you step…
Zorgatone
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3
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5 answers

What can be the reason of the constant 50 Hz sound in my home?

I am suffering from a strange hum in my home. I have just bought my home and living in 3 months. A month ago I've started to hear a humming noise. Then, I recorded the sound and looked at its frequency response. The peak was at 50 Hz. After a while,…
Ufuk
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3
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1 answer

What is the difference between the wave equation and the advection equation?

I am trying to understand what is the difference between the wave equation ad the advection equation? Bot the equation seems to move a quantity. While in literature it is said that the advection equation is the simpler of the two I don't see how the…
GRANZER
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2
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0 answers

How do you estimate the energy of an impact?

I am trying to determine the energy of elastic stress waves generated in a solid by an impact. I have a time domain waveform from a piezoelectric transducer that was placed next to the impact site, as well as the voltage/displacement calibration of…
Vishnu Venkatesh
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2
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2 answers

Is it possible for a microphone/sensor to detect soundwaves before it physically reaches the sensor?

I'm sorry if this is the wrong place to ask. I understand that for typical microphones, the sound waves need to physically reach the microphone and cause vibrations in the diaphragm before an electrical signal can be created. My question is, is…
user21600
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How do I set Reciprocating and Rotation motion in Fluent or CFX?

I want to model the following case(Attached picture) This case have reciprocating and rotation motion. Is it possible that this case models in Fluent or CFX without writing Code? How i set this reciprocation motion in CFX? Is it possible that give…
user19061
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1 answer

What causes wavelength technologies to have longer range than other despite having the same frequency?

Z-Wave operates at 868MHz (in EU) and has up to ~100-meter range LoRa operates at 868MHz (in EU) and has up to ~15 km range My knowledge says that the lower the frequency = the higher the range/penetrability. However, both these technologies…
Jazerix
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1
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1 answer

How is light guided by a perfect mirror waveguide for angles not exactly at the guided mode angles?

Take the below image for example: Let's imagine the cladding is really just perfect mirrors, where all light energy is reflected back towards the core. I understand that modes arise by imposing the condition that round-trip (two bounces) light must…
banjoeschmoe
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0 answers

Solution to wave equation in a stretched string with one end fixed and the other subject to periodic input

I have a uniform string of length $L$, linear mass density $\mu$, subject to tension $T$. It satisfies the wave equation: $$\frac{\partial^2 y}{\partial t^2}=c^2\frac{\partial^2 y}{\partial x^2}$$ where $y(x,t)$ is its displacement and…
JP19774028
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2 answers

How to generate a repeating semi-circle waveform using a mechanical linkage

How can one, in a smooth way, produce a semicircle wave, as opposed to a sinusoidal wave ? Imagining the machinery and linkages behind the movement. I mean the trace. For example a point fixed in wheel of a car may engender a cycloid. Others curves…
mitchi rodri
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vote
1 answer

Ripple tank simulation for simulating light waves?

Can anyone help shedding some light on how ripple tanks are programmed? example I'm looking to simulate light waves, to perform theoretical calculations, as opposed to for just visual effect. The ones I've found lack the ability to set a specific…
Morgan Gethin Barrett
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1
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1 answer

Upper frequency limit of transmission line

How would I determine the upper frequency limit of a transmission line from these plots? I plotted these in matlab after being given some RLCG values. About all I can seem to understand from these plots is when I can start using the high frequency…
stuart
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1
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2 answers

How can I calculate the total signal level (noise) of PC fans?

I have a fan on a PC case running at 100% speed making 40dB/A of noise (sound pressure). Then I add a second fan right next to it running at 100% speed making 30dB/A of noise. What is the combined noise level? What happens if add and extra 50dB/A…
Vulkan
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1
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0 answers

Best way to communicate data wirelessly with specific conditions

So I need two modules to give each other data with the following conditions: They are relatively short range. They need to be near each other to transmit the data, say around 5 cm. They are relatively small. Battery powered, preferably ready to…
MikhailTal
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