Laminar flow: Unintended consequences?

[Paul Workman]

Air has mass, and therefore subject to Newton's laws of motion. We've had lots of discussions about porting and the shaping of ports to smooth the flow, and avoiding edges resulting in reversion, etc. SO, with that in mind, this intake duct design (the shape!!) has always bugged me a bit.

As the air entering at the far right and left move toward the duct, the direction is vectored so the flow opposes. IF that isn't bad enough, it then has to make a right angle turn. The result has to be some compression (read: increased pressure) as well as turbulance as air tries to jam itself into the duct. Want more? the inlet to the air duct is essentially a hole cut in a perpendicular surface. It might be another area that could at least be improved with a "belled" inlet area, at least. No?



An "S" shape is what we see in aircraft engine inlet ducts, for example, AND the stock ZR-1 duct too, for that matter.



So, in spite of how "purdy" this duct is, I have to wonder if the shape of the box leading into the air duct is counter productive. That's not to say that in spite of it's perceived short-commings that it doesn't flow better than stock, or even a K&N. But, could it be better if the shape were different???

Oh, and ya want another shape that you won't see on a jet engine's inlet surfaces? You ain't gonna see no accordion-shaped ducting leading into the compressor neither!! (Oh, and you can see a bit of the "S" of the stock filter air box leading into the duct...)



I don't know what (if any) additional hp might be realized by using a more "S" shapped funnel (read: venturi) trasition from the filter air box to the air duct, OR what increase might be afforded by smoothing the accordion duct, but I'm sure Sir Issac Newton would not dissapprove! ... Just a thought!! Any JPL scientists in the house??

Jeeeessst stirrin' the pot.

P.

[DaveK]

Interesting ideas. Does anyone have access to any CFD type software to model this stuff?

[cvette98pacecar]

Originally Posted by Paul Workman

Air has mass, and therefore subject to Newton's laws of motion. We've had lots of discussions about porting and the shaping of ports to smooth the flow, and avoiding edges resulting in reversion, etc. SO, with that in mind, this intake duct design (the shape!!) has always bugged me a bit.

As the air entering at the far right and left move toward the duct, the direction is vectored so the flow opposes. IF that isn't bad enough, it then has to make a right angle turn. The result has to be some compression (read: increased pressure) as well as turbulance as air tries to jam itself into the duct. Want more? the inlet to the air duct is essentially a hole cut in a perpendicular surface. It might be another area that could at least be improved with a "belled" inlet area, at least. No?



An "S" shape is what we see in aircraft engine inlet ducts, for example, AND the stock ZR-1 duct too, for that matter.



So, in spite of how "purdy" this duct is, I have to wonder if the shape of the box leading into the air duct is counter productive. That's not to say that in spite of it's perceived short-commings that it doesn't flow better than stock, or even a K&N. But, could it be better if the shape were different???

Oh, and ya want another shape that you won't see on a jet engine's inlet surfaces? You ain't gonna see no accordion-shaped ducting leading into the compressor neither!! (Oh, and you can see a bit of the "S" of the stock filter air box leading into the duct...)



I don't know what (if any) additional hp might be realized by using a more "S" shapped funnel (read: venturi) trasition from the filter air box to the air duct, OR what increase might be afforded by smoothing the accordion duct, but I'm sure Sir Issac Newton would not dissapprove! ... Just a thought!! Any JPL scientists in the house??

Jeeeessst stirrin' the pot.

P.

This was my concern when I saw this air box, Will the chock point still supply enough air volume? Does anyone have the internal volume of the intake end of an LT5?

[Blue Flame Restorations]

Paul, a baffle welded inside on each side, as to eliminate the backflow in the corners, would be all it needs to solve that particular issue.

I would think, unless yo're doing VERY high speeds, there wouldn't be an issue. I just like the "look" over the stock plastic unit.

[John Boothby]

I use the Samco intake duct. It is smooth and will not collapse. However, it is thicker than the accordian duct and can rub on the A/C compressor pully and hood.

[Paul Workman]

Originally Posted by Blue Flame Restorations

Paul, a baffle welded inside on each side, as to eliminate the backflow in the corners, would be all it needs to solve that particular issue.

I would think, unless yo're doing VERY high speeds, there wouldn't be an issue. I just like the "look" over the stock plastic unit.

A BAFFLE might be just the answer.

P.

[LGAFF]

I would think the SS version outflows the stock based upon the amount of flow just under the and behind the filter were it bends...it pinches pretty good, and not sure your diagrams account for that....

[ALZR1]

Originally Posted by Paul Workman

Air has mass, and therefore subject to Newton's laws of motion. We've had lots of discussions about porting and the shaping of ports to smooth the flow, and avoiding edges resulting in reversion, etc. SO, with that in mind, this intake duct design (the shape!!) has always bugged me a bit.

As the air entering at the far right and left move toward the duct, the direction is vectored so the flow opposes. IF that isn't bad enough, it then has to make a right angle turn. The result has to be some compression (read: increased pressure) as well as turbulance as air tries to jam itself into the duct. Want more? the inlet to the air duct is essentially a hole cut in a perpendicular surface. It might be another area that could at least be improved with a "belled" inlet area, at least. No?



An "S" shape is what we see in aircraft engine inlet ducts, for example, AND the stock ZR-1 duct too, for that matter.



So, in spite of how "purdy" this duct is, I have to wonder if the shape of the box leading into the air duct is counter productive. That's not to say that in spite of it's perceived short-commings that it doesn't flow better than stock, or even a K&N. But, could it be better if the shape were different???

Oh, and ya want another shape that you won't see on a jet engine's inlet surfaces? You ain't gonna see no accordion-shaped ducting leading into the compressor neither!! (Oh, and you can see a bit of the "S" of the stock filter air box leading into the duct...)



I don't know what (if any) additional hp might be realized by using a more "S" shapped funnel (read: venturi) trasition from the filter air box to the air duct, OR what increase might be afforded by smoothing the accordion duct, but I'm sure Sir Issac Newton would not dissapprove! ... Just a thought!! Any JPL scientists in the house??

Jeeeessst stirrin' the pot.

P.

looking at your illustrations you're showing air as it moves through the air box
as if air was being bushed in.That's not the case here the Engine is pulling the air in.I Would think air bahaves differently in A vacuum state.Smoother is better for sure.

AL.

[DaveK]

Actually the air IS being pushed in - by the overall ambient air pressure.

[mike100]

Push and pull is kind of a weird description for air as everything is a pressure differential independent of gravity and such. the only thing that makes sense is when you get a head of steam on a fast moving air column- that's when it has some kind of inertia like a physical object.