Liquid Cooled Whoosh Rocket 

I had a vortexgasm watching this video

My science teacher has 9.5 fingers because of woosh bottles. Glad to see you are being safe about them

I was led here by such channels as integza and dollar store thor. When I saw you taping a plastic bottle, I knew that I hadn't been misled.

I wonder if you kept the incoming coolant/fuel separated from the outgoing exhaust for longer by extending the cap further into the bottle neck if there wouldn't be quite so much fuel being expelled, and therefore more fuel cooling the bottle. if you went far enough into the bottle then it could double as a fuel reservoir when you invert it.

Have you thought about a double-walled chamber? A bottle in a bottle, with the fuel circulating between them to cool the inner chamber. Either way, this is super interesting and I can't wait to see what you do with it!

Makes one appreciate even more rocket scientists. It is quite hard to make rocket engines.

I think what might help with your air injection issue is if you watch TechIngredients' video on hybrid nozzles, you should basically get a fogger nozzle to distribute the air smoothly around the whole inside of the bottle. More evenly diffuse airflow would help prevent airflow "hotspots" on the sides of the bottle that would cause dry-out conditions. As a bonus, the metal fogger nozzles won't catch fire like your saran wrap does lol. As far as inverting the bottle, you could probably take advantage of the 5 little stumpy nubs on the bottom of the bottle and put 5 little pintle injectors in them to flood the sides of the bottle with alcohol. You'd have a huge excess of fuel coming out the nozzle that way, but you might be able to take advantage of your swirly injector nozzle thing to inject more air to try and take advantage of that.

I love these rocket videos so much. I dunno what it is about rockets that makes my little brain light up with joy, but seeing that flame front travel down the bottle always gets me. It might not be feasible, but an external water film could help with cooling. The biggest issue would be getting it to actually film up, but cleaning the exterior of the bottle thoroughly and adding a wetting agent should help. As for how you'd deliver the water, I guess the same sort of spinny thing, but that's designed for the exterior.

Thanks for the link to the "smarter every day" channel, it's cool you help them out getting some exposure!

try an air diffuser that spins so that the flame doesn't get time to heat one place unevenly. if done in a specific way you may get a flame tornado effect in the bottle

Love the way you are thinkering about problems...

I used a model rocket engine to power a mini turbo pump. Pumped together kerosene and red fuming nitric acid; for about 3 seconds lol. I think it only made it as long as it took to spool up enough pressure to, well, disassemble itself lol. I was nowhere near it because I was pretty sure it was going to happen. Probably the coolest project I've done in years. I'll have a video up soon enough.

I love how you run straight towards danger in the name of science. It's a no wonder integza made a post about this video. You're in good company.

Damn, your previous video helped us to get a "good" on a project on our university of applied science, but this one would be good enough for a complete gradiate internship. These video's are the diamonds on yt for mechanical engineering 😁

This seems like a bomb with extra steps

Two things come to mind, 1. Put aquarium pumps in series or parallel to increase flow and/or pressure depending on needs. 2. Look for the most common points of failure on the bottle (by the video it seems to be where the curve on the neck is sharpest and the sides closest to the air inlet) and add additional fuel-spiny-inlet-thingys to compensate. sorry for bad English

That venturi effect at the top is definitely causing the failure reversing the flow of the cooling film back up and out. How about submerging the bottle in water up to the neck. you would have to deal with bouncy but that would dissipate all the heat and any unforeseen fires would be instantly snuffed.

That hawk screeching was the coolest part of the video... nature beats engineering every day.

Fantastic work! Super inspiring, I spent a little time on whoosh rockets too. Turning your rocket upsidedown, and having the coolant flow the same direction as the exhaust is definitely going to help. I imagine the problem is preventing too much fuel from being lost in the exhaust flow. You could 3D print a collar inside the bottle throat which collects and recycles the non vaporized film coolant back around the loop. Almost a reverse of your existing system. Totally looking forward to seeing your progress!!

Such amazing content. Last pick to RU-vid famous. Love it!

The return of the king

Amazing how much you can do with (comparedly) simple methods !

You deserve a happy algorythm :)

I just had an idea: A water rocket, but the pressure is provided by combustion exhaust. This would reduce the need for a heavy tank to hold pressured air.

I love the idea of simplyfying a rocket engine to the absolute basic principles, including the actively cooled walls. My suggestion for improving the cooling film would be a stronger pump, like PC coolant pumps with flow rates of up to 600 L/h. With a small enough ring nozzle, the alcohol should spread out more evenly and much faster. It's own inertia prevents further disruption by the combistion gases. Otherwise, the idea of turning the engine and coolant flow 180° is not to far from the cooling methodes of older rocket motors. The bigger specimens burned a fuel rich mixture on the nozzles closest to the chamber wall. This would creat a kind of isolating non flammable gas layer between the flame and the chamber wall.

It looks like the bottle is trying to become the perfect shape

Really cool video! Can't wait to see what's next!

"I will never financially recover from this."

Nice! That was a fun expansion of the woosh rockets, and I’m excited to see you flip it upside down in the future for a potentially longer burn time. Great video as always!

I just discovered this channel a few days ago and now I'm enjoying the rocket science contents

babe, wake up new scienceish video dropped

Your hella cool videos really help me out, so I hope this comment helps ya back. So, you want to continue these rockets, and you want to work on something mechanical? Try thinking about what parts of a rocket engine depend on mechanics. Better yet, something experimental or something weird and irrelevant that use mechanics! -What setting would change how the rocket behaves? If the rocket is moving in a normal or abnormal way, what does it do to the rocket? -Are there better ways to ignite this rocket? -What else can you spin? (spinning makes everything work better) -Is there a way you can apply this cooling system to where doesn't depend on where gravity is? All great experiments that I'd love to try. Think mechanical, lol.

You should put a shield around the oxygen inlet to try and mitigate the side blow outs you get. Try and direct it more towards the nozzle instead.

Out of boredom quite a while ago I built something similar that might be kind of a fun experiment for you! I took a 24 oz can of monster energy and threaded an air nozzle into the bottom. I cut a hole just big enough for the cap of the can to fit into at the bottom of the can on the side. I then used safety wire to hang the cap upsidedown about a half an inch below the mouthpiece on the inside of the can and put a small amount of isopropyl alcohol in it. You then ignite that small amount of isopropyl in the cap and put the compressed air to it and end up with massive flames shooting feet out the top of the can until all the isopropyl burns up.

Woah this worked way better than i thought it would! Great stuff!

You could try adding a CO2 inlet and button into these projects so when something goes wrong, you can quickly not only turn off fuel and oxidizer, but also extinguish any remaining combustion.

Pre-shrunk the bottle with hot water to thicken the walls and put the preshrunk on inside a none shrunk bottle might help also

Good teacher will use this as an example bad ones will use this for a whole class

You should put two bottles together making the rocket double walled and fill the space between the walls with alcohol to eliminate dry spots and spraying fuel out of the nozzle

Honestly, I wish I had a brain to be able to come up with these ideas

It kind of looked like the direction of input of the diffused air was pointing at the side and that may have caused the damage to the side of the bottle

I love your videos!

Awesome video definitely looking forward to more. I think printing a new nozzle with an extended tube inside the neck of the bottles so that the pressurized flow’s exit path is further away from the path of the isopropyl alcohol. Minimize the interaction between high velocity flow and the walls being cooled. The tricky bit would be making the tube as thin walled as possible to minimize throat restriction.

Can't wait next part 😁

That was awesome, thanks for sharing!

my suggestion would be to take a page from nasa and use tubing coiled around the outside. if you can get it right you can use the cooling coil to heat your iso to its vaporization point then inject it into your combustion chamber for optimal combustion. if you want to continue with your current version then lower the psi of the air to the point where you are no longer loosing fuel, remember that the forces of gasses leaving will need to be accounted for.

I love this video!

This is cool AF it served as a great proof of concept can't wait to see what you do with it next also good to see you telling of the danger of these angry little sods I damn near burnt half my hand playing with these bad boys when I was a kid

Absolutely amazing, you motivated me to make my own vortex rocket engine

Keep exploring this, it's super interesting!

Yess Finally ,upload again !!!

First of all, great video! It’s really informative! A quick suggestion: Real rocket nozzles often tend to circulate the fuel on the outer wall of the nozzles. You could cut a pipe in half and wrap it around the bottle so that the open half faces the bottle and the closed half faces the outside. Circulating fuel through this pipe would then help cool the walls of the bottle. You could then circulate the pipe back to the base of the bottle to reuse the fuel. PS: Cooling the fuel would also help!

For the next experiment (assuming you're going to flip the orientation of the bottle) what if you combined two bottles by cutting the bottoms off, & nesting one inside the other (bonding with glue/epoxy) , so that you have double-thickness for the body of the combustion chamber and two necks, one at the top and one at the bottom. Because of the shape, that configuration would lend itself better to the film cooling, as it's more curved, with fewer sharp angles and cavities. Just an idea.

Again great video! If you turn the bottle upside down you could use water as a cooling fluid. As its flowing down, it protects the walls from melting and in the end it safes the nozzle from burning of. The fuel then has to be injected. The water and the fuel have to go into the bottle at a greater pressure than the combustion pressure. Therefor you could use two resovoirs with one for water and the other one for fuel. These resovoirs are then pressurized with air. The pressure there has to be a little bit higher than the combustion pressure.

very cool video man

interesting please continue to make videos similar to this

AAAAAAAAAWwesome man!! cant wait to see what you n integza come up with "TOGETHER"

WOW! I was always wondering how to make the woosh rockets burn longer and you did it! I am really impressed and fascinated, I hope you will continue this series and maybe add a parts diagram for the rocket because I really want to build one! Thank you for this great video!

this channel is going places

Yup I'm enjoying it

this is amazingggg

Ok, here's a low tech tip that just might work. Attach a garden hose to your rocket, so the water cools it from the outside. Not sure if you know, but you can boil water in a bottle/plastic container in an open fire.

adding a check valve might help a little and they're easy to 3d print

Super cool ❤

this is beautiful bro...

Wauuu! 🔝🔝 I'm impressed how you fixed the problem with the pump. I would like to see a second video about this, looks too challenging to make it work. Nice video!

We back???!!! Let's gooooooooooo

loved everything here, especially the hawks :)

Nozzle pointing down, double walled chamber, just my two cents, pretty much just commenting for the alogrithm cause this is FIRE and i want more of it!!!!

Great channel

I recommend using carbon fiber polypropylene for your prints. I've been using that and carbon fiber PETG to build small fuel tanks for my little rocket project I've been working on. The CF polypropylene is harder to print but the layer adhesion is amazing, its very easy to make them hold pressure printing them on my prusa. I've had my CF poly tanks hold up to 400 psi with no leaks at all! CF Poly also has better temp resistance.

Wow, you're ending up at a hybrid rocket

What if you went lower on the air pressure rather than higher? I really think that is killing your way of cooling because it is just throwing the majority of your cooling out the nozzle

I'm curious what would happen if you just immersed the entire bottle in a tub of water, and did a normal run of it.

What if in your nozzle you have a pool around the edge to catch the liquid (with the bottle upside down), you can angle it slightly to funnel it into the exit hole, that way the liquid that comes down the sides, flows into the little pool and the pressure in the bottle pushes the liquid into the pipe. If the wall of the pool is high enough it won't interfere with the jet stream going through the nozzle in the middle. Clever wall design should also allow you to make the pool the right shape of "air pocket" to push the jet stream towards the nozzle without slowing it to a standstill. Lemme know if this doesn't make sense.

Use a thin fabric liner for the bottle. This will act as a wick and allow transpiration cooling of the wall. If the fabric is thin enough, it will be transparent when wet, so we can still see the flame.

To me it looks like the main reason for failure was likely the liquid cooling was halted largely once the air pressure was added

Awesome!

If you tried injecting the alcohol slightly below the neck (I know adding holes adds weaknesses but bear with me), the jet speed will be much lower at the point of entry and hopefully less alcohol would be carried out in the exhaust, giving better cooling. You'd probably have to inject it at an angle so that it spirals and wets the bottle better. Maybe add an afterburner for the exhaust as well? Anyway, another great video!

Hey that approach to cooling is also done on other internal combustion engines by spraying more fuel than cann be bunned so if you use 2 oxygen supply locations one at the bottom spraying in the fuel grating a oversaturated spray that coats the walls and the pressure will pusch the alcohol along side the wall (adding a small percentage of water to the fuel could also help for the droplets to reach the walls) and a second that air supply near the throat to burn of the excess fuel because all the fuel spray is making the shock diamonds invisible

Very interesting

Keep it up! Subbed 4 fun & interesting videos 😜

Water cooled outside combustion chamber would be interesting to test.

Pretty clever...

You should have your fuel draining down the sides in the same direction as the burn direction.

So hear me out. Put a bottle inside a slightly bigger bottle run the fuel in from the top and in the space between the two bottles. The interior bottle can be the combustion chamber, the outside bottle will keep the fuel in contact with the outside of the inner combustion chamber to provide cooling. Maybe the heat of combustion chamber could vaporize the fuel enough to pressurize the whole system then you would only need one fuel input 🤔

If that lumber caught fire, you would need a loan to buy some more

Squarospike looks like an exhaust fan

Metal mesh will absorb some heat before hitting the plastic bottle wall

Ever thought about ceramics? You can use those ceramic coatings on the internal surface. Would need a couple dozen coats but might work. Or a simple tempered glass bottle? One of those that don't break even when smashed

Awesome video! Quick idea I had that may help is to switch over to a gear or diaphragm pump. Those kind of pumps actually self-prime and produce quite substantial amounts of pressure. That may improve the issue with the reverse flow from the back pressure inside the combustion chamber. you can find small gear or diaphragm pumps on eBay for about $20 which can produce ~110PSI (or more) on the output with decent flow, too. they are commonly used for RVs showers & faucets.

Making the nozzle out of wood was actually a good idea but you missed a couple steps to strengthen it. Put it in a toaster oven for maybe 30 minutes at 150 degrees(not sure how it would react being 3D printed) but worth a try to remove all moisture then take a torch and just hit the inside to pre char it before running. That should increase its heat resistance and strength substantially. I would try(this is based on how I saw your 3D printed nozzle but maybe I just can’t see it right) to angle your fuel outlets almost parallel with the neck of the bottle but also at an angle where the fuel would spiral along the walls instead of just going straight. I would also use more fuel outlets that are smaller but not too small wear you get straight atomization out of the gate. You could also lengthen the air tube to bring it closer to the nozzle, keep your high pressure but reduce your cfm/quantity of air flow to not over fill the bottle with air. My last recommendation(bc I know you want to keep the bottle clear to see what’s going on inside) is to pick up some clear cerakote and pour in the bottle and swish it around to coat the whole bottle. O and go to any home improvement store and pick up a roll of aluminum foil tape to rap that fuel line up. Also, I know I said last recommendation 2 recommendations ago, why aren’t you lighting the outside of the rocket nozzle instead of lighting the inside like you have. It may or may not stop the fire ball from going into the bottle. I’m not rocket scientist so don’t take my recommendations as some PhD level anything lol. Just some things to try and see if it works or not. If my ideas work, I humbly request that you send a recommendation to MIT as an aerospace engineering professor in my name with your model as my reference 🤣.

I'm thinking the issue is you are not getting a laminar flow from your cooling stream. This is likely due to the inconsistent surface caused by 3D printing is likely causing coolant gaps that caused the burnouts. I would suggest trying the same STL on a resin printer and see if you can get a whole 4 seconds of life expectancy. lol One day after I finish school I'd like to start a channel similar to Destin's. I am actually finishing my BS in aerospace engineering at the same school he is pursuing his Ph.D. Our lives took very different paths as we are fairly close in age.

I wonder if you could go full on Linus Tech tips and water cool the whole thing? Just get bottles that are close to fitting in one another or like get a 3 liter soda bottle to fit around your 2 liter bottles and just cut it in half and tape it back together to get the 2 liter insider the 3 liter bottle and pump water through that gap the whole time! I think it would even take longer without a pump because the walls would start off much cooler and with much more thermal mass backing them up.

“I can guarantee…. probably” - this guy 2021

Cool!

I realize this might be kind of a hassle but I bet if you spin the bottle (you could use some sort of a 3D printed water filled labyrinth seal or something) it might give the film a better chance of not drying up. Maybe that would also allow the engine to work in different orientations other than vertical. Great video mate, really inspiring content 👍.

My "squaerospike" comment made the video! Eternal internet fame is mine!

Preheat bottom of bottle or full to shrink it. That will make wall stronger and increase thickness of alcohol on walls. As well if you move air inlet much lower you can in easy way increase time as part of heat will be dispersed by alcohol on bottom of bottle.

Try it underwater :D, or with cooling liquid on outer wall of bottle. We all watched Bear Grylls boil water in plastic bottle over fire... you won't get sustained burn but pretty sure it will burn decent amount of fuel