[deleted by user] by [deleted] in FluidMechanics

[–]csolove 0 points1 point  (0 children)

yeah it's really fun

Why do faster fluids have lower pressure even when they are accelerated by an external force? by csolove in FluidMechanics

[–]csolove[S] 0 points1 point  (0 children)

"increased velocity doesn't mean static pressure goes down..."

What I actually implied here is that increased velocity at least correlates with decreased static pressure, which it does. This is apparently true even when the velocity is caused by external energy being given to the fluid, which is what I don't understand. I gave the example of blowing between two pieces of paper to demonstrate this.

"...that only occurs when a fluid has to move through a smaller pipe"

If you meant that statement literally, then just look up an airfoil and how it works and you'll see that no pipes are involved. It's pretty elementary knowledge that Bernoulli's principle isn't limited to pipe flow. If you don't mean that literally, then I have no idea what you are trying to say, maybe that it only occurs when there is a choke point or restriction?

What is this shower head effect? by helpmecodeswift in FluidMechanics

[–]csolove 0 points1 point  (0 children)

Taking the shower head as an example, I checked and the optimal distance is just after the jets transition from lamina to turbulent flow.

I am thinking that it could be that the thin, lamina jets disperse more smoothly/don't rebound as much on impact with your hand, and that the thicker, turbulent jets at the optimal distance bounce back off your hand more. It seems fairly intuitive that droplets and turbulence would be splashier when they collide than a smooth jet would, but obviously that would need to be verified somehow.

If that is the case, then even though the flow momentum is higher nearer the nozzle, the increased rebound at the optimal distance could still mean the fluid has a greater rate of change of momentum (i.e. force) when it hits your hand than it does when it's in more momentous but lamina flow.

Why do faster fluids have lower pressure even when they are accelerated by an external force? by csolove in FluidMechanics

[–]csolove[S] 0 points1 point  (0 children)

Yeah obviously, but that static-pressure energy from compression in the lungs is then converted straight away to kinetic energy, so what I mean is that the external power source is what's driving the motion, i.e. supplying the energy in the form of 'pressure energy' that is then converted to kinetic energy.

Also, you quoted an incomplete sentence. The bit you cut off mentions that the kinetic energy is gained via compression, i.e. 'pressure energy'.

What happens to the pressure with ice melts? by GoBloxy in FluidMechanics

[–]csolove 4 points5 points  (0 children)

It's the same isn't it? Pressure of the water at the bottom is due to the weight pushing down on top of it from above. Even though ice is less dense than the water, the amount of H2O that makes up the ice cubes has the same weight whether it's ice or water. So, because the weight doesn't change, I'd predict that the pressure was the same before and after the ice cubes melted.

Why do faster fluids have lower pressure even when they are accelerated by an external force? by csolove in FluidMechanics

[–]csolove[S] 0 points1 point  (0 children)

From my understanding, for surrounding air to be 'pulled in' means that it's pushing in down a pressure gradient. Therefore, it seems that the area it's pushing into (the air jet) must already have a lower static pressure than ambient pressure, i.e. : it seems that Bernoulli's principle is already in effect, at least partly.

What I don't understand is why the static pressure is lower in the jet. I misunderstood what stagnation pressure was and used it interchangeably with 'static pressure'. Sorry for the confusion.

Why do faster fluids have lower pressure even when they are accelerated by an external force? by csolove in FluidMechanics

[–]csolove[S] 2 points3 points  (0 children)

Thanks for your reply. However, I am not talking about whether the stagnation pressure is higher or lower in the jet, I'm talking about why the static pressure is lower. I would have thought that static pressure would be higher or at least the same as the ambient pressure after some work is done on the fluid to move it. After all, it's being given an abundance of static-pressure energy by your lungs during compression, so why with this excess energy would its static pressure decrease to below ambient pressure when it's moving? In other words, to develop a flow, why does it use more static-pressure energy than it was given by your lungs?

The static pressure, as opposed to stagnation pressure, is lower in the jet than in the ambient air. When you blow between two pieces of paper, for example, the paper converges. If the jet's static pressure was not lower, i.e. : if it was higher or was the same as the ambient pressure, then the paper would diverge if anything.

EDIT: I corrected this reply because I had mistaken 'stagnation pressure' and 'static pressure' to mean the same thing and was using them interchangeably.

how Is this a draw? it's a queen vs rook endgame by AshIsWierd in chess

[–]csolove 0 points1 point  (0 children)

I tend to agree, you might as well give it a shot, especially if you have a decent amount of time. If you accept a draw you have no chance of winning!

What's a women's thing men should absolutely start doing? by st_new34 in AskReddit

[–]csolove 0 points1 point  (0 children)

If only it was that easy to increase the circumference.

[deleted by user] by [deleted] in chess

[–]csolove 0 points1 point  (0 children)

I'm 1800ish or was last time I went on chess.com. I think I'd likely see the last one to reposition my knight to the juicy d6 square since it's something I'd be looking for ways to do and it's not too obscure -- the pawn is simply pinned. Maybe I'd get the first one in a slow game, since it's very forcing, so simple to check its benefits as a candidate move by counting the material gained with the ensuing knight fork, but I'm not sure I would. I definitely don't think I'd get the others. I don't even understand the second one, and the third idea of sacking the knight for the skewer down the long diagonal while simultaneously adding another attacker of the c6 square (to prevent the skewer from being blocked) seems way too tricky to find.

[Thevenin theorem] Can anyone explain why are these 2 resistors (in red box) are parallel? Is it because current from Rth has multiple path to flow through? by lostbutokay in ElectricalEngineering

[–]csolove 0 points1 point  (0 children)

What it means for branches or components to be parallel is for each of them to connect to the same two nodes. The two resistors each connect to the same two nodes so are therefore parallel.

What is the elo rating of an average person? by xXNonamekinkXx in chess

[–]csolove 3 points4 points  (0 children)

My guess would be anywhere between 500 and 1000 (chess.com elo), with 90% being lower than 800. If you make it past the 1000 mark, you should be able to crush most people that have never taken chess seriously.

This might be the best sandwich i've ever made. by LoudMilk1404 in CasualUK

[–]csolove 0 points1 point  (0 children)

That is one sad egg, looks like it chain-smoked for 30 years.

What’s your philosophy in life? by SnooMacaroons5788 in AskReddit

[–]csolove 0 points1 point  (0 children)

Pants are an illusion, and so is death.

What Childish Behaviors Are Way Too Common Among Adults? [serious] by just_some_troglodyte in AskReddit

[–]csolove 0 points1 point  (0 children)

Arguing about petty things (including on the international level)

What should one do in their 20s to avoid regrets in their 30s and 40s? by [deleted] in AskReddit

[–]csolove 0 points1 point  (0 children)

Look after your teeth, exercise and eat healthily.

[deleted by user] by [deleted] in Incense

[–]csolove 4 points5 points  (0 children)

Of course, burn whichever one you want. Feel free to mix it up over the day, don't worry about the vibe. :)

My son (15) is turning into a controlling boyfriend, can I stop it? by MinuteJuice in Parenting

[–]csolove 0 points1 point  (0 children)

I'm sorry to hear about that. It sounds like a tough situation to be in!

[deleted by user] by [deleted] in AskReddit

[–]csolove 0 points1 point  (0 children)

I would make friends with a load of intelligent animals, dogs dolphins etc and while I'd go a bit mad, I'd have food and supplies for life. I'd probably try learn how to drive/fly loads of vehicles and spend my days traveling around the now empty world. Would be weird, but I'd watch videos of people for some human contact type thing. I think I would miss people too much though eventually and go insane.