ATOT, let's see how many of you get this right.

[lxskllr]

Can a fan blow pressure? Isn't there a better term for that? It seems to me it would be 4psi, but moving quicker.

 

[destrekor]

Think of it as a fan that's blowing 4PSI by itself, regardless of what the input pressure is (of course less than 4PSI). In this case, the input pressure is already 4 PSI.

I'm just trying to make a point.

Your vague response is the opposite of what I was seeking.


So, the fan will always push out 4psi, regardless of the input? Does that mean it does or does not add to the current pressure?

So... 8psi? (my first guess after finding out it wasn't a wall )

fluid dynamics is not something I can say I "get".

 

[Matthiasa]

Top pipe: Psi ummm not sure maybe the same most likely.The flow rate however would be ~half. (volume per time is the same same)

Bottom pipe: same and same

Unless it's all one thing... I'm bad with badly draw pictures with no explanation of what their suppose to be.

 

[Meghan54]

but then...why do people do push pull on heatsinks?

They do it because there are loses to the push fan's output from the heatsink.

 

[Rubycon]

Fans don't blow psi.
You can make it like an electrical circuit (I always like the reference to pressure = voltage because high pressure potential sounds nice ).

You have a damper symbol in the lower diagram - a propeller would indicate a fan. Now that is cleared up...

Flow would increase if you keep things simple and avoid all the other nonsense some guy named Bernoulli came up with.

Push pull heatsinks can help with getting the heat OUT of the box. In the open their flow rate sums certainly do NOT match the equivalent CFM of a single fan would provide on one side...

 

[SSSnail]

LOL, would you guys be happier if I said "compressor"? Look at the quality of the artwork, thanks care.

 

[Matthiasa]

LOL, would you guys be happier if I said "compressor"? Look at the quality of the artwork, thanks care.

So its at 4 psi then its "compressing" it to 4 psi?

 

[SSSnail]

So its at 4 psi then its "compressing" it to 4 psi?

That's for you to figure out. It's not that complex, simple pressures logic, really.

It could be a genie that pushes out 4 PSI with his flatulence, same difference.

 

[lxskllr]

That's for you to figure out. It's not that complex, simple pressures logic, really.

It could be a genie that pushes out 4 PSI with his flatulence, same difference.

This may end up wrapped in semantics, and technical details, but if that's a compressor, compressing at 4psi, then it's 4psi coming out. It would be compressing nothing since the regulator would keep the 4psi pressure on both sides.

 

[Matthiasa]

That's for you to figure out. It's not that complex, simple pressures logic, really.

It could be a genie that pushes out 4 PSI with his flatulence, same difference.

Well you have a 4 psi writen on both sides of it so... Yeah...

 

[LordMorpheus]

This is regarding a thread in the garage about an engine with a couple turbos feeding a supercharger. A good chunk of the posters are convinced that the intake manifold wouldn't see turbo pressure differential + supercharger pressure differential above atmosphere.

 

[SSSnail]

This may end up wrapped in semantics, and technical details, but if that's a compressor, compressing at 4psi, then it's 4psi coming out. It would be compressing nothing since the regulator would keep the 4psi pressure on both sides.

Right, and the earliest people that replied didn't have any problems with the concept either.

This is regarding a thread in the garage about an engine with a couple turbos feeding a supercharger. A good chunk of the posters are convinced that the intake manifold wouldn't see turbo pressure differential + supercharger pressure differential above atmosphere.

It's elementary physics.

 

[Rubycon]

This is regarding a thread in the garage about an engine with a couple turbos feeding a supercharger. A good chunk of the posters are convinced that the intake manifold wouldn't see turbo pressure differential + supercharger pressure differential above atmosphere.

A supercharger is positive displacement. If the turbos can produce enough FLOW to increase the input pressure on its suction side then there will be a higher pressure on its discharge side and an increase in MAP. Why anyone would want to do this is beyond me especially when you can cascade blowers.

 

[SSSnail]

A supercharger is positive displacement. If the turbos can produce enough FLOW to increase the input pressure on its suction side then there will be a higher pressure on its discharge side and an increase in MAP. Why anyone would want to do this is beyond me especially when you can cascade blowers.

He was arguing that if a turbo that puts out 15PSI and a supercharger that puts out 15PSI into an intake you'll see 30PSI at the manifold...

 

[lxskllr]

He was arguing that if a turbo that puts out 15PSI and a supercharger that puts out 15PSI into an intake you'll see 30PSI at the manifold...

That's silly. I'm just a dummy, and I know better :^D

 

[IronWing]

Did you ever notice that PSI sounds like a leaking tire? Psiiiiiiiii......

 

[Rubycon]

He was arguing that if a turbo that puts out 15PSI and a supercharger that puts out 15PSI into an intake you'll see 30PSI at the manifold...

Not that simple.
Let me see if I still have Gale Banks' phone number handy.

WTF is the DJ playing Christmas music? It's not December...is it???!

Did you ever notice that PSI sounds like a leaking tire? Psiiiiiiiii......

ROFL yes I've caught myself saying what's the pissy?

 

[DrPizza]

I've done virtually nothing with fluid mechanics in 20 years, so I'm very rusty. But I keep coming back to Bernoulli. If you go from a higher volume to a lower volume, velocity increases in the narrower pipe. But, contrary to "common sense", the pressure actually decreases. (Or am I getting this principle mixed up - been 20+ years.) Also, I was thinking in terms of liquids, not air.

 

[Fenixgoon]

I've done virtually nothing with fluid mechanics in 20 years, so I'm very rusty. But I keep coming back to Bernoulli. If you go from a higher volume to a lower volume, velocity increases in the narrower pipe. But, contrary to "common sense", the pressure actually decreases. (Or am I getting this principle mixed up - been 20+ years.) Also, I was thinking in terms of liquids, not air.

nope, you're right. the pressure term in the bernoulli equation essentially represents the amount of potential energy available to the fluid, and the velocity term is the kinetic energy. a higher velocity requires a drop in pressure, and vice versa.

@ SSSnail the whole point of a compressor is to increase pressure at the cost of adding heat. if the pressure is the same on both sides of the compressor, then it isn't doing any work, if i'm not mistaken.

 

[El Guaraguao]

eleventeen pseye. wtf do i win?

 

[Rubycon]

the whole point of a compressor is to increase pressure at the cost of adding heat. if the pressure is the same on both sides of the compressor, then it isn't doing any work, if i'm not mistaken.

Yes it would be pointless indeed.
A charge cooler gets rid of the heat.

 

[Matthiasa]

Okay im changing answer to < 4 psi for the first but would need to know more info for an answer
Dumb equations...

Oh and I'm bored so need different questions.

 

[LordMorpheus]

That's silly. I'm just a dummy, and I know better :^D

You think so? if you see a 15 psi differential across the turbo, and a 15 psi differential across the supercharger, what differential do you think you see between the intake manifold and the atmosphere?

You'll probably have to turn the supercharger and the turbos faster in order to maintain those differentials (due to the higher flowrate, and the fact that neither a turbo nor a supercharger is an ideal pressure source) than you would if either device was operating by itself. Still. Two compressors in series. The total differential pressure is the sum of the differential pressures of each. Well, I guess in this case it's two turbos in parallel, in series with a supercharger.

The only way the system wouldn't be beneficial would be if you did a terrible job designing it and had the super turning too slow to do any good. Most (although certainly not all) of the gearheads that have the resources and the knowhow to put something like this together know better.

Educate yourselves: http://en.wikipedia.org/wiki/Twincharger

 

[PM650]

Pat Buchanan

The ballot was confusing!!

 

[KingGheedora]

Are either of these on a large conveyor belt?