Recent content by vco

The underlying PDE is the Cauchy momentum equation. It is just Newton II expressed for a continuum. Note that the ##\mathbf f## in it contains body forces only, like gravity. The more typical types of external forces come into play as boundary conditions for stress. Edit: clarifications

Recently I started wondering why there seems to be so few practical/engineering applications where you need to calculate the momentum of something. I must emphasize that I don't mean usage of the concept of momentum or the law of conservation of momentum, but the value of the quantity itself...

Quite right. :smile: I was just wondering whether the "direct" approach was known to be significantly worse in terms of performance compared to the apparently more common FFT approach. The original signal will be used as input/reference for certain engineering calculations where the signal is...

I need to perform a phase shift for a measured time domain signal. The signal consists of around 1000 points. I wrote an algorithm for this in Python a while ago and it seems to work as intended, but now I noticed that the algorithm is actually unexpectedly slow. Is it so that phase shifting is...

There was an old thread comparing the difficulty of classical mechanics and electromagnetism. The consensus was that electromagnetism is more difficult, and substantially so according to some. The thread was no longer open for replies, but it got me suspecting that we're comparing apples to...

Yes, maybe I should have used the word "complex" instead. But I didn't necessarily refer to the number of rotating parts. I meant the complexity of involved engineering/physics. With a piston engine you have for example reactive fluid dynamics inside a rapidly changing domain. For example the...

Ever since electric cars became increasingly popular I've been wondering whether there are some other examples where new technology is less "advanced" than the old. I mean, electric motors are considerably simpler technologically compared to piston engines. Are there more such examples or is...

What a strange question. :smile: I think most cities in the "East" have comparable technologies to the United States. No Silicon Valley there, though. Nowadays, probably none. It's a global world. Same as above. But as a historic example, the US was a bit late to adopt cellphone usage. I live...

I would imagine the procedure is indeed relatively rare. But what about motorsports, for example Formula One? Surely the teams perform such analyses since the engines are rarely, if ever, running in steady-state conditions and fierce competition requires simulations to be as realistic as possible?

By transient vibration I mean that the engine speed and torque are changing as a function of time, as opposed to steady-state vibration where the engine is being run at a constant speed and torque. Well, to be exact the instantaneous values for the engine speed and torque are changing in both...

How is the transient vibration of a piston engine usually simulated? I know that in order to define the vibration loading you need the mass properties and dimensions of the moving components plus the cylinder pressure curve. And of course you need to know the firing order, V-angle (if...

I seem to be in a minority for thinking that mechanical engineering is more difficult than electrical engineering. Difficult for me, I mean. To me, mechanical engineering is more difficult largely because in mechanics your intuition and common sense are often trying to mislead you. With...

I don't think turning radius is the explanation. Even without the maneuver, when approaching the corner the car would still be positioned on the outer edge of the road (the "racing line"). The system is perhaps too complicated to be satisfactorily described with elementary physics, which may...

That makes sense, but I don't see why we couldn't attribute both of these definitions to the second law.

So there is no strict reason we couldn't state that there are only 2 laws of motion instead of 3?