Do any vaporizers besides the ELEV8R and the Supreme use "laminar flow?"

[~vapeslut.xo~]

http://www.supremev.com/

On this site the man who makes the Supreme talks about the airflow in most vaporizers,
and how the Supreme is, well, supreme because of something called "laminar flow."

As i understand it means that the air passing through the herb, only 10% of it is hot.
THe way the Supreme is designed, 100% of the air is hot!
This is called, or related to, laminar flow...


In a regular vaporizer only the red part is hot air! The blue dots are regular air that isn't heating the herb.


I tried to Google the heck out of this! But i only saw a single thread, here
that said "the Elev8r has a similar 'laminar flow' number, as the Supreme..."

And of course these two vapes stand out very prominently with those who have used them!
So there must be something to this "flow" concept!

So i find all this very interesting, why can't I find anything on Google?
Please let me know where i can learn more!

 

[west-elec]

I think @invertedisdead has gone into it a bit in his thread on the inversion vape concept. Some of his designs are all about this type of thing. Check that thread out.
Very basically the friction of the walls of a tube slow air flow nearer the sides so flow gets concentrated in the centre. Laminar flow is spread out and even.
I wouldn't think the elev8r qualifies, the dimples would spread out airflow but not in a laminar fashion. More chaotic I would think.
Just considering it now off the top of my head, the FP heads with many holes directly above the bowl comes to mind. That new Deskpod glass head?
Many portables use screens just above the herb to spread and even out the flow, but not really true laminar I guess.

 

[invertedisdead]

Ed actually says the Supreme is better than other vapes because it’s not relying on laminar flow. That's why he talks about the air being forced to turn.

However as @west-elec points out, the Flowerpot is a great example of laminar flow, and definitely an ass kicker of a vape.

The Elev8r with beads is more like the Supreme, utilizing turbulent mixing to heat the air. Realistically both flow regimes are valid, it really just depends on the particular design goals. The fluid dynamics is only one variable, which is generally heavily compounded by other design decisions. IMO there are other elements to the Supreme design that play a large role in its effectiveness. In stock configuration it receives a heavy conduction boost from the bowl design.

 

[badbee]

Generally laminar flow is not good for convection which relies on heated air moving around freely. Air is actually a very poor conductor of heat. That's why foam insulates so well, it's due to the tiny air pockets that the air can't move out of, not the polymer material. When air flow is laminar it means molecules tend to stay in their track, either straight up the center or along the edge but not mixing much. That reduces heat transfer from coil\heater to the air stream and from the air stream to any kind of cooling stem wall.

 

[~vapeslut.xo~]

Ed actually says the Supreme is better than other vapes because it’s not relying on laminar flow. That's why he talks about the air being forced to turn.

However as @west-elec points out, the Flowerpot is a great example of laminar flow, and definitely an ass kicker of a vape.

The Elev8r with beads is more like the Supreme, utilizing turbulent mixing to heat the air. Realistically both flow regimes are valid, it really just depends on the particular design goals. The fluid dynamics is only one variable, which is generally heavily compounded by other design decisions. IMO there are other elements to the Supreme design that play a large role in its effectiveness. In stock configuration it receives a heavy conduction boost from the bowl design.

Oh wow...I see!
Have you used both? I would love your thoughts on the Elev8r "vs" the Supreme!

 

[arb]

Ed actually says the Supreme is better than other vapes because it’s not relying on laminar flow. That's why he talks about the air being forced to turn.

However as @west-elec points out, the Flowerpot is a great example of laminar flow, and definitely an ass kicker of a vape.

The Elev8r with beads is more like the Supreme, utilizing turbulent mixing to heat the air. Realistically both flow regimes are valid, it really just depends on the particular design goals. The fluid dynamics is only one variable, which is generally heavily compounded by other design decisions. IMO there are other elements to the Supreme design that play a large role in its effectiveness. In stock configuration it receives a heavy conduction boost from the bowl design.

What type of airflow does a Alpha have?

 

[oldfool]

 

[arb]

I was skeptical until I saw the technical drawing in the second video.
I was especially impressed with the "squirty bits" and the care taken with assembly.

Actually was a great visual demonstration and explained it well I think.

 

[invertedisdead]

What type of airflow does a Alpha have?

Log airflow takes a turn when moving from the air inlet to the heater core, but I would expect the flow to remain mostly laminar as it passes through the core. Though current research suggests "laminar" vs "turbulent" flow is often oversimplified, with a new focus on the equally important transition region.

 

[Farid]

It's important to make some definitions clear. Laminar and turbulent are both ways of characterizing flow regimes/patterns.

Laminar Flow: This is flow that is characterized by smooth streamlines with fluid flowing in parallel layers
Turbulent Flow: This is flow that is characterized by irregular streamlines with fluid layers mixing and chaotic changes in the pressure and flow velocity

The flow type is going to be different in different parts of the vaporizer. You can have turbulent flow through the heater section, but by the time it reaches the herb chamber it could be laminar.

The reason turbulence is often desired in the heater section is because turbulence causes more contact between the wall of the heater and the air passing through it. This leads to increased heat being transferred from the heater to the air.

In the herb chamber, I have a suspicion that turbulent flow might be beneficial for even extraction, because with laminar flow the center of the pipe has a higher velocity than the edges, versus turbulent flow leads to a more even velocity profile through the pipe. As shown in this figure depicting the average velocity profile in a pipe's cross section:




There is a layer of air surrounding the walls called the boundary layer. As @west-elec points out, with laminar flow the velocity at the boundary is zero due to the "no slip boundary condition". Turbulent flow is able to overcome this condition, which is the reason there is more contact with the walls with turbulent flow, and also the reason the average velocity profile is more even with turbulent flow (shown in above figure).

To your point about statement "the Elev8r has a similar 'laminar flow' number, as the Supreme..." I think this is a major oversimplification. The number I imagine they are referring to here is the Reynold's number. But this is only useful for comparing different parts of the vaporizer, since any vaporizer will have a different Reynold's numbers at different places along the airflow. So in reality comparing the Reynold's numbers between vaporizers provides no real useful data, since every design is different. Even if you compare the Reynold's number within the heaters of two vaporizers, that number will vary widely at different positions in the heater.

The red circle with blue dots is also an incredibly misleading figure, that is of very little value. The reason this is of little value is because airflow does not behave like that, in fact it almost behaves the opposite way with laminar flow. Air heated at the walls of the pipe does not stay at the walls. If you were to heat a straight pipe and draw air through it (while maintaining laminar flow), the center of the pipe would have the hot air, not the edges. In fact, since this is supposed to be representative of laminar flow, it would probably be the edges where the air was the least hot due to the no slip condition.

I agree with idea that turbulent flow is beneficial in the heater section to maximize efficiency, but this way of presenting the information seems poor.

To claim that a certain flow type is unique to one vaporizer seems to me to be an obvious oversimplification for the sake of marketing. There are certainly unique benefits of the Supreme's heat exchanger, but it is definitely not the only vaporizer to take advantage of this principle.

 

[arb]

A turbulent flow makes a turn into a tube how far up the tube until its laminar?

 

[MinnBobber]

IMO, I think laminar airflow at the low air velocity in vapes tends to be a better extractor. I use miniVAP as my example: the ABV is exactly the same color without stirring.
At the polar opposite of laminar lies the Taffee Bowle where the air takes massive direction changes and the ABV is not nearly as uniform in color.

Laminar vs turbulent seems more relevant in high velocity airflow situations, like internal combustion engines. Me thinks the Suzuki Twin Swirl Combustion Chamber of GS1100 fame was the innovator of better flow and mix with turbulent airflow.

 

[Farid]

IMO, I think laminar airflow at the low air velocity in vapes tends to be a better extractor. I use miniVAP as my example: the ABV is exactly the same color without stirring.
At the polar opposite of laminar lies the Taffee Bowle where the air takes massive direction changes and the ABV is not nearly as uniform in color.

Laminar vs turbulent seems more relevant in high velocity airflow situations, like internal combustion engines. Me thinks the Suzuki Twin Swirl Combustion Chamber of GS1100 fame was the innovator of better flow and mix with turbulent airflow.

I may be wrong but I'm fairly certain the inventor of the Supreme is referring to turbulent flow through the heater being ideal, not through the herb chamber. What you describe is the flow through the herb chamber, which can be laminar while the airflow through the heater is still turbulent.

Whether flow through the herb chamber being laminar or turbulent is better is something I've considered, and I'm very open to changing my opinion, since there's a lot at play.

But I think there's little doubt that turbulent flow through the heater is more efficient. Almost every convection vaporizer I know of has some sections of turbulence through the heater, and it's a principle central to heat exchanger design.

 

[arb]

My experience is two straight tubes seems to be "better" than having any taper.

 

[Cheebsy]

A turbulent flow makes a turn into a tube how far up the tube until its laminar?

Guess work here but I think velocity, diameter and internal surface finish would make significant differences.....


In other words... *shrug*

 

[Planck]

@Farid excellent post #10 in this thread.

I hope everyone interested in this thread will take the time to watch this video, I promise most will know more about flow at the end than at the beginning.

 

[Shadooz]

However as @west-elec points out, the Flowerpot is a great example of laminar flow, and definitely an ass kicker of a vape.

But that's why it must run at +700F.. lower exchange, but make them steady

Even with the herborizer, which have non-laminar output (cyclonic). I can end up with a laminar output if i draw like a pig, And so hotspot.. (due to the 14mm bowl being wider than the exhaust)

More than "turbulence effect", it's just time and area which are good for heat transfer. turbulence increase them.
but with too high velocity draw, it will just end up into depressure bubble, which are the worst for heat transfer, and/or eveness of bowl

The supreme, is def a laminar heating flow and output. But a compressed one, unlike flowerpot, with unpressure/pressure point (small turbulence area) on turning edges.
The issue with laminar as heating flow, will just be the low exchange surface/time, period.
Which is avoid by the supreme pathway (high surfaces).

Therefore, turbulent airflow is good if no/low depressurize area. And laminar if un-overfocused flow.
The balance is most of the time the best. But for both, it's a too veloce draw that will make them less efficient. Just don't draw like a pig (sry french expression...)

A simple summary

 

[Farid]

With the flowerpot, I'm pretty sure the 19 hole diffuser triggers turbulence where the air enters. Putting all those small diameter holes next to each other causes the stream tube to break up into 19 parts, and that process of diffusion likely causes turbulence

This is assisted by an effect in which, in very small diameter channels, the surface forces start to play a bigger role which is normally dominated by volumetric forces. This can be attributed to the boundary layer taking up a higher percentage of the volume in a small tube versus a larger tube.

Of course we can't discount the increased surface area in contact with the flowing air with the diffuser's design, this is also the case with the Supreme's labyrinth style diffusion. This plays a huge role as well, regardless of the flow type.

The only convection vape I can think of that could be entirely laminar flow and still work well is the Sticky Brick. And that works because the air enters the vaporizer already heated, it is not being heated by the walls of the glass tube.

 

[Shadooz]

With the flowerpot, I'm pretty sure the 19 hole diffuser triggers turbulence where the air enters.

The turbulence will only occur close to those holes, then the high airflow will get back the turbulence to laminar.
The more u pull, the faster laminar it will get back, with the overfocus cons it gives.

It would have been true if it was an over pressure flow, not an under pressurize one.

And Like for computer case, you always need to avoid over or under pressure to get the best exchange. And so put the same ammount of intake fan and out-take ones.

It's always a mix of laminar and turbulence, every time there is pressure point.

Turbulence increase heat transfer but reduce airflow (and can make it too chaotic, uneven), laminar increase airflow but reduce exchange and can hotspot.
a compromise between those two is the way to avoid hotspot and optimise heat exchange.

The flowerpot is still one of the least heat exchange of the market, that's why it needs that huge ammount of really hot titanium.
Compared to the herborizer, which compress the "laminar with turbulence" flow, between the titanium and the glass.

And for the title of this thread, the elv8r work best with a turbulence flow (ruby pearls), compared to the laminar of without ones.

 

[Farid]

I've never used a flowerpot, so I don't know what the draw resistance feels like. You may be right. I was basing my assumptions on diagrams from google haha.

But one reason I hypothesize there is turbulence is how short the heater is. This would also explain why the heater temperature is so high.

The turbulence will only occur close to those holes, then the high airflow will get back the turbulence to laminar.
The more u pull, the faster laminar it will get back, with the overfocus cons it gives.

Where the air exits the diffuser it will have returned to a laminar state. But since the diffuser is so short I wouldn't be surprised if the entrance region is a decent portion of the entire diffuser path, and that the increased velocity through the diffuser makes turbulence more pronounced.

Another reason the flowerpot likely has to run at a higher temp is the constant heat loss due to a lack of any external insulation.

Still I wouldn't be shocked to find that it is mostly laminar flow throughout, since the many small holes means a much higher surface area of contact with the air.

The more u pull, the faster laminar it will get back, with the overfocus cons it gives.

By "more you pull" are you referring to the longer the draw, or the harder the draw?

Because that's another aspect of discussion we haven't gotten into yet, the effect the draw has on flow. Going from no flow to high flow (as occurs when we inhale) has some effects at the beginning of the draw which diminish over time. But an inhalation is naturally going to be over a limited time, since nobody has infinite lungs.

That's another reason the conventional examples we use to describe these phenomena (like a pipe example, or an industrial heat exchanger example) are not perfectly analogous. Since many of those applications are based around a constant flow.

I love this thread, cause it's really challenging me to think about some preconceived notions I have about fluids. So much of what we learned in school was based on the classic examples (mostly constantly flowing pipes and flow over plates), and vaporizers are really different in their "stop/start" short durational use.

 

[arb]

I've never used a flowerpot, so I don't know what the draw resistance feels like. You may be right. I was basing my assumptions on diagrams from google haha.

But one reason I hypothesize there is turbulence is how short the heater is. This would also explain why the heater temperature is so high.



Where the air exits the diffuser it will have returned to a laminar state. But since the diffuser is so short I wouldn't be surprised if the entrance region is a decent portion of the entire diffuser path, and that the increased velocity through the diffuser makes turbulence more pronounced.

Another reason the flowerpot likely has to run at a higher temp is the constant heat loss due to a lack of any external insulation.

Still I wouldn't be shocked to find that it is mostly laminar flow throughout, since the many small holes means a much higher surface area of contact with the air.



By "more you pull" are you referring to the longer the draw, or the harder the draw?

Because that's another aspect of discussion we haven't gotten into yet, the effect the draw has on flow. Going from no flow to high flow (as occurs when we inhale) has some effects at the beginning of the draw which diminish over time. But an inhalation is naturally going to be over a limited time, since nobody has infinite lungs.

That's another reason the conventional examples we use to describe these phenomena (like a pipe example, or an industrial heat exchanger example) are not perfectly analogous. Since many of those applications are based around a constant flow.

I love this thread, cause it's really challenging me to think about some preconceived notions I have about fluids. So much of what we learned in school was based on the classic examples (mostly constantly flowing pipes and flow over plates), and vaporizers are really different in their "stop/start" short durational use.

The short distances come into play also I suspect.

 

[Cheebsy]

@Farid excellent post #10 in this thread.

I hope everyone interested in this thread will take the time to watch this video, I promise most will know more about flow at the end than at the beginning.

Thanks for that video @Planck it was really interesting

 

[Shadooz]

Where the air exits the diffuser it will have returned to a laminar state. But since the diffuser is so short I wouldn't be surprised if the entrance region is a decent portion of the entire diffuser path, and that the increased velocity through the diffuser makes turbulence more pronounced.

The flowerpot is not that short. It's not the box mod. (Which are mostly laminar, even if they bring turbulence in contact area.)
i don't own one either, only an herborizer that's why i talk about it.
But as i said, here it's a depressure flow. It must be thought from the other way. Lungs to heater. Or just bowl to heater, here, for the part we are interested on, in this thread.
And turbulence will just be attract to those depressed area (aka the botom part of the showerhead).
Depression will bring back laminar way faster than u think. Even more with higher airflow

By "more you pull" are you referring to the longer the draw, or the harder the draw?

Harder (not better, faster, stronger.. XD)

[ for @invertedisdead

"Work it harder, make it better
Do it faster makes us stronger
More than ever hour after hour
Work is never over"

..InVerZion

Sry for that "aside" ]

But i've already talken about that :

But for both, it's a too veloce draw that will make them less efficient. Just don't draw like a pig (sry french expression...)

For the max vapour by inhale, slower will give more, basic heat transfer.
u can't cook pasta in 1 seconde. U can't beat time. (Reason why dab is easier, faster)

Going from no flow to high flow

That's why i always start slow, less initial loss (which will just give an initial useless blast, which is useless as cooking is time related)

 

[invertedisdead]

And for the title of this thread, the elv8r work best with a turbulence flow (ruby pearls), compared to the laminar of without ones.

This is what I mean when talking about the compounded effect of multiple variables as a result of just one change. The rubies definitely do add more turbulent airflow, but they also do a LOT of other stuff. They bridge the heat transfer across the heater via conduction, they store more heat, they conduct heat faster, there’s a major heated surface area increase, more residence time, greater pressure drop etc. Basically trying to say that the same end results are often explained in different manners.

That’s why I see an issue in generalizing flow regimes affect on vapor when there’s so much other stuff going on with just that one change. For example one major benefit to the supreme is its made of aluminum, so it heats more evenly than others. Regardless of flow, that makes a big difference on heat transfer.

Still I wouldn't be shocked to find that it is mostly laminar flow throughout, since the many small holes means a much higher surface area of contact with the air.

That’s what I think too, the FP immediately partitions the air down a 19 lane highway that just produces a different effect than having a lot of surface area but sending everything through the same inlet. That’s why I switched from the single hole inlet to multi hole in my desktop, to divide the flow into multiple lanes

The flowerpot is still one of the least heat exchange of the market, that's why it needs that huge ammount of really hot titanium.
Compared to the herborizer, which compress the "laminar with turbulence" flow, between the titanium and the glass.

I think the heating style has a large effect on this too, for example the FP emits a ton of radiant heat but it has nowhere to go but up. Herborizer is sealed up top besides the two inlet holes, plus with an insulative glass housing to store heat.

Before I built my desktop I made the Evo On A Stick from the DIY section, which involves fastening beads inside a glass joint with just a basket screen. After trying it I knew I had to switch to a full glass enclosure as there was so much radiant heat being lost with the open top. You could feel the warmth on your face when hitting it.

 

[Shadooz]

greater pressure drop

Pressure drop is a cons here. Which Reduce exchange. A Reason to go more easyly on inhalation.

The other cons will be the chaotic output.
The vapbong for exemple.
A Laminar airflow on a really hot coil. But If u draw not enough, u will end up with chaotic turbulence in the big bowl. And With the higher thermal flow due to more residence time. It ends up hot spotting. One of the only where slower draw will make hotspot.