Placeholder Image

Subtitles section Play video

  • Hey, it's me Destin, welcome back to Smarter Every Day.

  • I love,

  • laminar flow.

  • And people send me tweets about laminar flow,

  • all over the internet, its time to do,

  • the laminar flow video.

  • Check this out, big pool.

  • We're going to see if we can make, laminar flow happen.

  • I should be able to poke a hole, in this pool,

  • and get a glassy looking jet,

  • that comes out this pool. That's what laminar flow is.

  • It's very orderly, looks like glass.

  • Okay, so here we go, ready,

  • three, two, this feels so wrong.

  • Let's see if we get laminar flow,

  • no, we don't.

  • (laughs)

  • Now I've got a hole in a pool.

  • Okay, laminar flow is a function of geometry,

  • obviously I had the wrong geometry.

  • We're going to try a big spike, here we go.

  • Oh golly.

  • Okay. (Laughs)

  • Alright.

  • No, it doesn't work.

  • So my shape's not right.

  • My shape's not right, what do I do.

  • Work, work, work, work with me.

  • Ah, there we go, okay, so.

  • I got laminar flow right here,

  • and its going turbulent, right here.

  • Why?

  • Laminar flow is a function of the geometry, the velocity,

  • and the kinematic viscosity,

  • of the fluid that you're working with.

  • Right now, my velocity, is not fast enough,

  • to have laminar flow, because there's not enough pressure,

  • so if I move it down, I should have more pressure.

  • So, let's plug this back up,

  • well now I have a problem.

  • That's out.

  • I'm doing a bad job of explaining laminar flow,

  • what we need to do, we need to go, around the world,

  • to different places I've observed laminar flow

  • in the past several years.

  • And we need to let me show you, various things

  • that I've seen along the way.

  • Laminar flow is orderly, all streamlines are parallel,

  • and there's no mixing of the flow.

  • It's all like how you would imagine,

  • water flowing through pipe,

  • everything is straight and parallel.

  • Turbulent flow however, is chaotic,

  • there's pressure fluctuations throughout,

  • you get the idea.

  • Engineers have this special term,

  • called the Reynolds Number.

  • To try and help predict, what type of flow,

  • they might be dealing with.

  • The top of the equation are the things

  • that describe the flow itself,

  • like the velocity, the density, the geometry, etc.

  • But the bottom of the equation is viscosity of the fluid.

  • Like how thick the fluid is, like water vs honey.

  • A lower Reynolds Number,

  • means that the flow is more laminar,

  • and in my opinion, more awesome.

  • But a high Reynolds Number means that it's more turbulent.

  • So if you look at the equation,

  • you can kinda see what's going on here.

  • If you have more viscosity,

  • that means Reynolds Number gets smaller,

  • therefore the flow is more laminar.

  • But if you increase the velocity of the flow,

  • or the size of the flow,

  • Reynolds Number gets bigger,

  • therefore you have more turbulent flow.

  • If you keep Reynolds Number and the mock number the same,

  • you can make a model of whatever you're trying to fly,

  • and you can get a good idea if turbulence or laminar flow

  • is going to happen over the model.

  • That's exactly what they did with the Saturn V,

  • this is the big Saturn V right here.

  • But in order to approximate what was going to happen,

  • they made a wind tunnel model.

  • You can use wind tunnel models,

  • like this little four inch model.

  • To approximate the flow, over the entire, Saturn V rocket.

  • As flow comes through here,

  • and goes across this Apollo capsule,

  • if the string flickers as turbulent flow,

  • if it's steady, it's laminar flow.

  • Check this out. (whirring)

  • So as we change the angle of attack,

  • you can see the different types of flow, take place.

  • It's a little hard to see it, with just the strings,

  • but Sarah-Kate, who goes to school with my daughter,

  • made an awesome science fair project.

  • You've got to see this.

  • Okay, to demonstrate laminar flow and turbulent flow,

  • this is Sarah-Kate, science fair winner, extraordinaire.

  • Right, - yes sir.

  • - [Destin] You going to show us how it works?

  • So NASA Glenn Research Center,

  • and you just built it from the plans?

  • - Yes sir,

  • - [Destin] That's awesome.

  • - [Sarah-Kate] I had parental supervision and guidance.

  • So you have to pick your scent.

  • - [Destin] Frankincense, dragons blood, that's pretty legit.

  • Orange, that's got to be good.

  • That's a weird smell.

  • - [Sarah-Kate] Okay, now I'll blow them out.

  • - [Destin] Okay, and so,

  • that's going to make the smoke come through,

  • this pipe right here right?

  • - [Sarah-Kate] Yep.

  • Now I'll turn on the fan.

  • (fan whirs)

  • - [Destin] So got to get the light correct, right?

  • - [Sarah-Kate] Yep.

  • - [Destin] Okay, so that's pulling it through,

  • should we be able to see it, yet?

  • - [Sarah-Kate] Yeah, you can already see it.

  • - [Destin] You can already see, oh what the heck.

  • You sure can,

  • look at that.

  • Oh that's cool, look at that.

  • Okay, cool, so, laminar flow,

  • are the straight lines that go across, correct?

  • - [Sarah-Kate] Yep.

  • - [Destin] So that's a zero angle of attack?

  • - [Sarah-Kate] Yes.

  • - [Destin] So give me a real high angle of attack.

  • There you go, look at that.

  • So we're getting flow separation,

  • along the backside here,

  • and we're getting turbulence back in here right?

  • - [Sarah-Kate] Mm hmm.

  • Let's see.

  • - [Destin] This is like

  • the coolest science fair project you've ever done?

  • - [Sarah-Kate] It's the only science fair project

  • I've ever done.

  • (laughs)

  • - [Destin] Look at that turbulence back there.

  • So ultimately, what were you trying to learn here?

  • - [Sarah-Kate] Basically, I was just trying to learn

  • more about, airflow shapes, and flow separation, and stall.

  • And make a good visual representation of all those things.

  • - [Destin] Well I think you accomplished that.

  • Look, man, look a it from this angle right here.

  • You can see, you can see the separation back there.

  • Look at that.

  • That's a really good angle.

  • This is an awesome experiment.

  • Are you going, you're going to regionals now right?

  • - [Sarah-Kate] Yes sir.

  • - [Destin] You're going to win.

  • Do it.

  • If you've ever been to the Detroit airport,

  • there's an awesome fountain,

  • like right in the middle of the whole concourse area.

  • And you can see laminar flow in action,

  • programmed with computers.

  • - [Destin] It's the awseomest fountain,

  • let's go look at it.

  • What do you call this flow?

  • That flow right there.

  • - Laminar flow.

  • - [Destin] What's it called? - Laminar flow.

  • - [Destin] Laminar flow,

  • some daddies don't teach their kids cool words like this.

  • - Oh, I already know alias.

  • - [Destin] Yeah?

  • - And all that other stuff.

  • - [Destin] You don't appreciate this.

  • - I do.

  • - [Destin] You just don't, you just don't appreciate, what.

  • You just don't appreciate laminar flow.

  • Let's go.

  • (phone buzzes)

  • Dude.

  • Did you get the funnel?

  • Yep, alright, so here we go.

  • Thank you.

  • Ow my finger.

  • Okay there we go.

  • This is a Go-Pro right?

  • So what's happening is,

  • the flow is going into the funnel,

  • and as the flow goes in there.

  • All of the streamlines of the water, are lining up.

  • And so its flowing parallel right,

  • once you get all the flow going in one direction.

  • You can divert the laminar flow, and the streamlines,

  • stay in the same orientation.

  • So look, you can start to make things like,

  • sheets you see that?

  • Look at that.

  • It's working.

  • That's got ridges on it.

  • (gasps)

  • Okay, look at this, so if you get

  • all the laminar flow going in one direction.

  • You can put things that,

  • look at that it made a bubble.

  • Okay, you can make a sheet, like a sphere, of laminar flow.

  • Okay, so there's a really cool children museum,

  • in Chattanooga, that I found this,

  • and I put my phone up under it.

  • Look at that, I could put my head in that.

  • That is beautiful.

  • This is probably my favorite kind of fountain.

  • And the cool thing about it,

  • is the flow rate at the center has to be high enough,

  • so that, it's glassy,

  • like you have enough flow to make a complete covering.

  • But it's not too high,

  • where you go turbulent at this location right here.

  • Right there.

  • See it's wanting to go turbulent, but it's not.

  • And as, the water, drops off.

  • There's enough volumetric flow, to cover and make it glassy,

  • 360 degrees here.

  • Which is awesome.

  • So what I'm going to do, is put my phone in there,

  • and see if we can see through the laminar flow.

  • Let's see if it's smooth enough.

  • Okay, you ready?

  • Another thing I like to think about,

  • is the inverse square law,

  • and the flow rate as it comes out.

  • Anyway here we go.

  • (muffled water flowing)

  • That works doesn't it?

  • So the next question is, can you hear me?

  • So it's totally engulfed with water,

  • I don't know if you can here me or not,

  • but the microphone is probably full of water at this point,

  • but let's try this.

  • Can you hear me better now?

  • I like this a lot.

  • (water flowing)

  • I like that a lot, okay.

  • It's really fun, when you're 30 something years old,

  • and you have to wait for the two year olds.

  • So you can do you're little fluid experiment.

  • I love laminar flow, and I want you to love it too.

  • Prince Rupert, you're in my light, move.

  • Thank you.

  • Okay, so, the thing that I think is so neat here,

  • is if you think about the volumetric flow rate,

  • if it's not enough,

  • you don't have water go all the way to the bottom.

  • You see how it's breaking up here.

  • But, if you control all of these variables, perfectly,

  • you can make a fountain do exactly what you want.

  • This is beautiful.

  • I really respect people that design fountains like this,

  • because it has to do with flow rate,

  • has to do with, pressure,

  • the nozzle geometry.

  • Anything, can disturb, the flow.

  • - [Destin] It's amazing watch, touch it, come here.

  • - [Woman] Oh, it's shot, it's up,

  • are we going to go up, and then down?

  • - [Destin] Yeah, touch it, touch it.

  • - Are we allowed to touch this?

  • - [Destin] Well we're doing it.

  • Ah that's so stinking cool,

  • I love it.

  • You know why I love it?

  • Laminar flow.

  • Can you imagine they had to perfectly level this,

  • because that's gravity fed.

  • And then you have to make sure the flow,

  • into the orifice there, is perfectly

  • perfectly level.

  • All the way across, oh my gosh.

  • This mall in Chicago wins, for the coolest fountain.

  • And probably the number one reason,

  • why I want you to love laminar flow,

  • and this is not an exaggeration.

  • We literally use laminar flow to protect the integrity

  • of the moon rocks.

  • And that is not an exaggeration.

  • So, I'm about to show you a clip of how that works,

  • and if you would like to consider

  • subscribing to Smarter Every Day, while we watch this,

  • this from a future episode.

  • - Now that we're dressed in our bunny suits,

  • we're going to go into our air shower,

  • and we stay in there for one minute.

  • And it's a laminar flow,

  • - [Destin] You have no idea how much,

  • - it separates between a less clean area, and a clean area.

  • - [Destin] You have no idea how much I like laminar flow.

  • (laughs)

  • - [Destin] You don't even know,

  • I can't even explain it to you.

  • - You really love it don't you.

  • (laughs) - [Destin] I do.

  • So here we go.

  • Laminar flow.

  • Is this going to make our hair fly around?

  • - No, it's not that kind.

  • - It's just really slow laminar flow.

  • - In the meteorite lab, they have the little tunnels,

  • that actually would make your hair flow,

  • they found that stirred up more particles.

  • So this was designed,

  • - Turbulence was bad. - Exactly, yes.

  • - That's why this is laminar.

  • - Laminar good, turbulence, bad.

  • - Got it, I dig it, I like laminar flow.

  • - That's our minute up.

  • - Is our minute up? - Yes.

  • - [Destin] Our microwave is done.

  • - [Andrea] So watch your step down.

  • - I'm watching it, boom.

  • Wow, alright.

  • Okay, I hope you enjoyed this video,

  • I'm going to do what's called, the soft sell.

  • I'm just going to give an option to you.

  • You can either take it or leave it.

  • I like exploring the world,

  • using goofy stuff like this.

  • And I film stuff all over the world,

  • and I throw it together in videos like this.

  • If you would like to consider

  • subscribing to Smarter Every Day.

  • It's basically a declaration for your love of laminar flow,

  • and low Reynolds Numbers.

  • That's pretty much what it is at this point.

  • So, if you would like to do that,

  • you may subscribe, if you feel like this video earned it.

  • And you could even hit the bell.

  • If you're not ashamed of it.

  • So, that's an option for ya.

  • If you'd like to subscribe to Smarter Every Day,

  • you can do that, if not, no big deal.

  • Thank you to everyone,

  • who sends me laminar flow pictures on twitter.

  • I really enjoy them.

  • I am Destin, this week, this video is sponsored by tacos.

  • I hope you enjoy that too, have a good one, bye.

  • - [Destin] What are you doing?

  • - Making tacos.

  • - Making tacos.

  • This episode of Smarter Every Day,

  • is sponsored by Hello Fresh.

  • Which is a meal kit delivery service,

  • which we use at the Sandlin house,

  • to cook meals and eat around the table as a family.

  • They send food to your house,

  • and you can just cook per the recipe, which is enclosed.

  • They have premeasured ingredients, it's a great thing.

  • The reason we like it,

  • is because it makes everything simple,

  • and how we do life, in the evenings.

  • And it let's us eat yummy food.

  • - [Destin] How do you know when they're done?

  • - Timer.

  • (laughs)

  • - So if you want to try this, I highly recommend it.

  • We love it.

  • You get really good food, and your kids learn how to cook.

  • You can do this by going to Hellofresh.com,

  • and use the promo code, smarter80.

  • For the New Year they have a special where you can get,

  • eight free meals basically,

  • 80 dollars off your first month of Hello Fresh.

  • Do that by going to HelloFresh.com,

  • use the promo code smarter80.

  • Come look at these tacos.

  • - [Destin] So am I at a taco truck?

  • - [Boy] Yep.

  • - [Destin] Nice.

  • Thanks for making me tacos.

  • - You're welcome.

  • - [Destin] Would you rather have tacos or a haircut?

  • - Tacos.

  • (laughs)

  • - [Destin] Will you get a haircut anyway?

  • - Yeah.

  • - [Destin] Okay.

  • So it works out to about 6.99 a serving,

  • which is a really good deal.

  • If you want 80 bucks off your first month of Hello Fresh,

  • go to HelloFresh.com and use the promo code smarter80,

  • and get 80 bucks off, it's good stuff.

  • Bye.

  • If you're mom doesn't love laminar flow,

  • your mom is wrong.

  • (laughs)

  • There's only one thing left to do, the taste test.

  • (laughs)

  • That was laminar flow.

  • Let's taste turbulent flow now.

  • Yeah laminar flow is better.

  • (laughs)

Hey, it's me Destin, welcome back to Smarter Every Day.

Subtitles and vocabulary

Click the word to look it up Click the word to find further inforamtion about it