What is the best FIREWALL material?
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- Опубліковано 29 чер 2024
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The DarkAero 1 prototype will use a firewall made from titanium sheet metal, ceramic insulation, and a honeycomb sandwich panel. We discuss why we selected at this material combination and show some testing of how our firewall might perform in the unlikely event of an engine fire. We also cover how our design relates to FAA regulations for certified aircraft firewalls, particularly FAR 23.1191.
00:00 - Intro
00:47 - What is a firewall?
01:57 - FAR 23.1191 - Firewalls
04:33 - Firewall Test Rig
05:57 - 2024-T3 Aluminum Test
07:17 - 304 Stainless Steel Test
09:37 - 304 SS + Blanket Test
12:26 - Titanium + Blanket Test
14:39 - Test Summary
14:57 - Outro
DarkAero 1 Aircraft - www.darkaero.com/aircraft
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The marshmallow man should be a standard part of every FAA firewall test.
Please post specs for the marshmallow man. This could save lives.
Marshmallow man merch needs to be a thing...
Can't wait for the Darkaero Marshmallow Man to make it into the FARs! Great work guys. I'm really enjoying watching good engineering practices in motion.
LOL next video from DarkAero: "I got a call from the FAA!" Glad you are enjoying the videos. We've been having fun creating them!
Dont forget the smoke coming from resin in the final carbon structure. We use a special UL94 resin for carbon firewalls with honeycomb on a racecar and they are a pain to work with. They need a specific tempering heat cycle after curing otherwise they become very brittle.
Can you kindly tell me.more about this UL94 Resin
The best extremely lightweight firewall material I've found to stop radiant heat is generally known as griddle brick material. I've used it in numerous composite builds since 1991. Grill Bricks are a pumice-like cleaning block made from recycled materials. Basalt is the primary ingredient. The conveyor furnaces that shape the raw ingredients is way north of 2,000 F. This material is also used in chemical plants to insulate high heat pipes. I have a source in the DFW area that purchases the 4' X 4' X 8" blocks then cuts it into half round radiuses to insulate pipes. The material is very brittle but has a very high impact absorption strength. It smells like Sulphur when cutting it or picking at it but the odor is safe for animals and humans. Incapsulated after cutting there is no smell. It's one of my proprietary composite blend secrets that I'm now releasing to the public. It will dull normal cutting tools in seconds. Cheers
We used fire brick and insulating block for radiant head stoppage in fuel fired boilers, it’s made out of the same material and we had firebox temps up to 2500f, out side temps were around 95f. That’s steady state running for hours. Great point you have!
You call a youtube comment a "public release" ?! .....lolz
@@_Joy_Unleashed - Most public releases to what was once considered intellectual property or proprietary are now freely available as a public release on UA-cam. I like open-source information. It's a shame many also post click bait and untrustworthy information as well. My intention is to offer what works especially when it comes to aviation projects and the great guys with DarkAero. I love spending time with their valuable channel. The plus side is reading the comments of their channel. A great community of folks in my opinion. Have a blessed day!
Great work guys, can't wait too see it in the air.
There are some other youtube aircraft projects that could learn a LOT from your group's adherence to engineering test principles. Awesome work.
Hey we don’t need a firewall when the engine is in the back! (Joking)
Pay attention to materials based on magnesium oxide. MgO boards with fiberglass have a very high fire resistance. Also on the US market there is a material called "Airkrete foam" based on MgO. It is a very lightweight refractory material used in construction as insulation. This material can be used in aviation because it is very lightweight.
How do you ensure the heat does not break the structure of the airplane apart? I mean, what good does the firewall do if the front falls off and the weight of the engine is gone.
I think I know the answer: you just need the motor mount to hold and it's quite solid going through the firewall.
Wow, that REALLY brings the seriousness of it all to light. (no pun intended)
Aerogel blanket right in front of the sandwich?
"Less expensive"
Sandwich the aerogel blanket? Carbon fiber all the things!
Carbon fibre on the front will burn. Keeping the Alu core seems good, but the CF must be protected by the blanket.
LOL. I like that they rejected your design. Great video. Thanks for sharing.
haha good eye!
I just found this project and am loving it! One thing I recommend though: have an "overview" video pinned to your UA-cam page. I don't think you even have a complete overview video of the project at all. Something that includes: goals, aircraft specs, mission, deadlines, etc. It could be almost like a commercial if you wanted to go the route.
I watched about a dozen videos before I finally realized I have to go to your site to find specs.
Silly to go to that extent? I think it's awesome. Love your views, research, and testing. Keep up the awesome work and videos.
Impressive combination of scientific thoroughness and light-hearted cheer.
Very nice video. Great build and great to see the progress being made!
I love the safety features!!!!
Great work! Living my dream. Keep up the content!
Aerogel? Love the marshmallow man! Was he good eating after the aluminum test?!!
This is exactly how cirrus aircraft firewall is built. Yes, it works....mostly. I've repaired one that caught fire. It stopped alot but not all. I was able to save the plane by replacing a large portion of the structural firewall then the entire fireproof metal and ceramic. It did save the pilot from harm
Really interesting. It’s amazing that just 1/16th of stainless or titanium held back a 2,000f blow force for so long!
Have you considered selling little bits of the honeycomb structure to help fund the project? Or would it not be economical? They just look so cool!
it's not 1/16", it is 0.016", almost 1/4 of 1/16"
Awesome, I’m building a cozy and that gave me reassurance.
What could be more "cosy" than curling up behind a glowing light aircraft firewall with a glass of red and a loved one, or a DarkAero marshmallow man? 😉
Another great vid! I'm very surprised FAA says nothing about radiant heat. Anyways - marshmallow test rocks. Question..after you finish Dark Aero 1, will you be developing a 2nd plane type optimized for other missions?
Thanks for watching Eric! We are pretty focused on the DarkAero 1 for now but we’ve definitely kicked around the idea for a DarkAero 2. Seems like it would be a logical progression if we are successful with the first design. :) One airplane at a time though!
@@DarkAeroInc aerobatic tandem one plus a four seater for bigger families... 😉
I would like to see an aptera like solar electric 4 seater car please! 😎👍
EXCELLENT guys! Fellow engineer; I really enjoy your work. Please share more about the Cozy you built!
Would it be possible to have a reflective air space that could be ventilated behind the Ti?
Alway interesting information. Thanks for sharing.
Very interesting and educational!
Great video, Ryley, with valuable information. Thanks!
After watching Scott Manley’s videos about Apollo issues I am more than supportive of proper parts testing. All the duration, all the parts, zero assumption.
These boys are 🔥🔥🔥
I do all my sketchy experiments in my driveway too!
My guess would be porous silicon rated to 2,300 degrees F or a 'Starlite' like material that forms carbon foam. Polishing the titanium layer can also assist against passing radiant heat to the cabin.
As far as I watched videos about starlite recreations the material would degrade over time.
Ryley, this is the best video I've ever seen on firewalls. I'm converting a single-place motorglider Silhouette to be all-electric. Each battery compartment needs to be a small vented fire-resistant environmentally controlled compartment. This was excellent reference material. Thanks!
Excellent! Really happy to hear this information was valuable for you!
Brilliant!
Nice work as usually... Have you heard of "starlight" ......non-commercial fire insulator.
I think that might be too fragile for continued use in flight. I would also suspect that the vibration and shifting of a failing engine in flight could knock away the carbon foam created pretty easily. It is a good idea, though, and I would like to see it tested. Maybe there is a spay version that could go over the finished firewall as extra layer of protection to give more time to the pilot.
@@David-yy6hp Good point regarding vibration effects - a practical and valid point that is NOT addressed in the FARs (at least not as covered in the video). Addition of starlite would still be an interesting test, even if some method to simulate engine vibration were added. I wonder if the light weight of the carbon foam might protect it from flaking due to mechanical vibration. Simply coating in 'starlight'-like material might also be prone to inadvertent mechanical damage in service (which would result in compromised protection), but it could be protected with a tough sacrificial coating.
@@robbmain1684 I saw a video by nighthawkinlight about making the coating stronger through the addition of borax, which created a glass-like binder for the carbon foam. A carbon/glass foam manufactured more cleanly might be a very good approach, but then it starts to mimic ceramics. I think that a carbon foam layer, if it could be made to withstand vibration, on the engine side of the firewall could be useful for heat dissipation due to the radiative properties and the air entrained inside of it. I would love to see some tests on carbon foam materials and their implementation cost as well.
Great way of explaining the FAA regulation! Amazing and educational 👍🏻😊 keep up the great videos. Keep marshmallow man safe!😂😂
If cost is not an issue the use of titanium is a very reasonable choice. As shown by other manufacturers some materials may just not be "necessary" to achieve the desired result cost effectively? Just the opinion of a former AF Crew Chief, if the engine fire was serious there would be melted blobs of engine aluminum flying around long before a firewall would fail. Cool vid to watch though and it's interesting to see the hoops you guys are jumping through to get FAA certified.
Great presentation.
And now I know I can wear my marsh mellow sneakers flying the DA1. They are sooo comfortable. The kids say, “they look so totally fresh!”
Remember only you can prevent marshmallow fires! Great video, you guys are going to end up with a great aircraft!
It would be interesting to know whether the firewall provides any structural strength to the aircraft's frame/body, and if so, what impacts the high temperatures have on it's structural integrity.
Which one of the brothers is going to put an application in with the FAA to be a DER?
Enjoying your content guys and watching your progress. About the Firewall. Perhaps you know already, but aluminium is the best material to accept ceramic coating.... that’s why they use it to coat pistons in very high performance racing engines. Perhaps you could have your first sheet in the firewall laminate structure ceramic coated?
I wonder about flames that aren't centered on the firewall. Imagine, for instance, that an oil line busts and sprays hot oil that then catches fire near the edge of the firewall.
What happens to the interface between the carbon fiber airplane structure and the firewall?
Also, how does a fire affect the structure of your front landing gear? IIRC, that's mostly aluminum and mostly forward of the firewall. Does the slot for the landing gear pose any kind of threat for ducting fire around the firewall? If the gear in the engine bay were to melt or warp during a fire, you'd presumably drop the nose onto the runway during the landing. Do you have any sense of whether the plane would tend to flip if this were to happen?
You guys are a huge inspiration. Thank you.
Great explanation as always👍🏻😉
Is it possible that the heat from the engine could make the canopy opaque or is it something really hard to happen?
Are you asking about just waste heat from the engine running? or heat from an engine fire? Either way, the canopy is made from thermoformed acrylic which will soften when it gets hot enough but it doesn't turn opaque. Thanks for watching! :)
@@DarkAeroInc Thank you for the answer😉
I was asking especially for engine fire sitation
Amazing work! I hope to see you in flight as soon as possible😉😉
Nice vid!
I’d definitely look into Aerogel as a first layer (although I’m not an engineer)
Aerogel's only rated to ~1200 degrees F. It would be a good second layer behind the titanium but it's also really expensive.
Aerogel is super expensive and very brittle.
I think it's a ceramic layer
@@jeppewerring I wonder if it could be sandwiched in a composite? I’m not a material engineer, this stuff just interests me.
I'm sure you guys have already settled on the design you are going to use for the firewall, but I'm curious. Did you think about infusing the honeycomb structure with starlite instead of the ceramic blanket, and if so, what would be the reasons to not use it? 😁
As far as I watched videos about starlite recreations the material would degrade over time. Wasn't starch one of the components?
I have a little secret about stainless steel. It does not radiate energy very well. You notice all those cool drinking mugs made from stainless? It's not just the vacuum that insulates. The high nickle chromium content refracts the energy back into itself. So yes it glows, but the transmitted energy is much less than carbon steel or titanium. I personally saw an old time wood stove with a brand new 16ga 304 stainless shell. You literally could not burn enough wood to heat a room. The top cast iron part was the only thing transmitting heat. The same stove before with carbon steel sides would run you out of the whole house in an hour. In my opinion this explains the less toasty marshmallow man on the stainless test. Really awesome test setup by the way.
You could try an emissive refractory coating to reflect some of the heat. ITC 100 or ITC 213 Ceramic Coating for example. You'll have to ask them if it keeps sticking over the years though...
It's interesting that the carbon weave is visible on the infrared.
Good work guys!!!
Can you PLEASE increase the audio output of your channel...it is way lower than other UA-cam videos.
For the carbon aluminum honeycomb sandwich panels did you guys use prepregs or some special method of wet lay up/ infusion? Really curious 🤔.
enjoying science class 🤟
My guess on the new secret material for the firewall is "reinforced carbon/carbon matrix". This is the material that was used on the space shuttle nose cone and leading edges of the wings. This material withstood the temps and shielded/protected the titanium super structure of the shuttle during reentry into earth's atmosphere. You guys have incredible carbon matrix composite skills already so this could be a reasonable next step for you.
AWESOME...........Just cool as heck....... Any chance you guys ever build the RC Version (1:3 or smaller) scale? Just to see what the smaller version would fly like? I know you performed fluid dynamics modeling to verify much if not all of your flight characteristics but was just curious? Anyway Thanks for all your sharing and looking forward to 2022.
Okay, I'm going to ask a dumb question: Would a halon fire suppression system for the firewall forward area makes sense? Oh, and add a fire sensor too.
Yes. Race Cars use those systems and they are mandatory in any professional racing. They weigh about 7-10lbs for a small one.
The only issue in an Airplane is the huge volume of air going thru the engine compartment will blow the Halon out the cowling immediately. Whereas a race-car usually crashes and stops before the extinguisher is utilized. An airplane can actually put the fire out by diving to VNE or Vd in some cases, and if that doesn't work to blow out the fire like a candle, at least you're diving toward the ground as fast as possible and will therefore land as quickly as possible.
In an aircraft, an IR sensor for heat or a wire that melts and illuminates a warning light in the cockpit could be beneficial.
For 304 ss + blanket are you guys concerned that the carbon face of the honeycomb panel will get hot enough to melt the aluminum layer?
Melt the resin long before AL.
Hi,
The honeycomb structure has many pockets of air, which can act as a micro pressure chamber on each air pocket when there is sudden increase in temperature and how do you solve these problems. Because you don't want to lose structural integrity of the firewall in that situation. Which leads to set of new problems.
Wouldn't an air gap be a better than having solid insulation? From my exhaust experience we typically use a stainless and insulator sand which and then an air gap between the surface to be protected. Doing the math, thin layers with air gaps are the best defense against radiated heat.
Good reason for going with a pusher design, IYAM.
Insted of just a solid layer of Ceramic insulation use grinded or flakes of it, it will fill it with more air hence more heat dissipation and lower temperature of marshmallow man✌️
Is it Teknofibra? That's used in F1 and Indycar to protect the driver...
How do you calculate cold temperatures and low pressure at high altitude. I assume every carbon fiber part would need to bleed pressure including the honeycomb cores.
With your testing its all well and good doing in house make shift testing but do you have to qualify your builds to proper standards like RTCA DO-160. Specifically section 26 talks about fire and flammability. I know a lot of COTS products will already have this but stuff you guys manufacture in house?
Go for Aerogel - congrats for the build!
$23,000 per lb?
Tungsten skin (foil), asbestos insulation blanket, then a Aramid fiber interior skin(Kevlar/Nomex). That combo would stop anything. I doubt any heat would transfer through it.
what's the specific ceramic blanket you selected? Brand/Model/Source?
Dark aero branded marshmallow man plushie when?
The first video of the Dark Aero marshmallow man plushie doing zero G indications would go so viral! LOL!
What temperature does the resin you use catch fire? A cirrus here in Colorado caught fire in flight and the fire went thru that plane real quick. Needless to say nobody survived.
I can see many pilots loving this plane for use as a fun stunt type plane due to its light weight and power to weight. I personally am looking for something like this as a business plane to shoot around to different states where I have job sites. Quick and efficient is perfect for me. 50-100 commercial flights a year minimum is more than I want to deal with anymore. Time for a personal plane.
It's not going to be certified for aerobatic flight so you're out of luck pal!
Curious: do FAR regs specify if firewall can be structural or must not be structural?
instead of the ceramic layer why not an Intumescent layer between the titanium and the CF sandwich? As it heats up it expands and provides greater level of safety. perhaps to the point where the cf sandwich would be undamaged.
I have a feeling the firewall youre trying out is Starlite and since its made from PVA glue mixed with corn starch and baking soda would be very cost effective. The fact you can coat your hand in it and then take an Oxy Acetylene torch to it is proof enough its the best firewall except for being ablative so it wears aways over time.
Take a look at basalt derived materials. Matting cloths wraps and ceramics..
In the aftermarket/racecar industry, gold foil tape is used on firewalls, that would be my guess to add some lightweight fire protection
I think you should think about adding Teknofibra to the firewall. It’s excellent for fireproofing as well as soundproofing. Maybe that’s the mystery material you’re talking about
How can I get a apprenticeship at Dark Aero...
Does DarkAero plan to incorporate a fire suppression system? It's common in racing but I don't know about aerospace as much.
Merchandising, merchandising, where the real money from the aircraft is made! DarkAero-the T-shirt, DarkAero-the Coloring Book, DarkAero-the Lunchbox, and last but not least DarkAero Marshmallow Man the Plush Doll!
But seriously, if you put that Marshmallow Man schematic on a t-shirt I'll be the first to buy it.
What about the heat transmitted through the engine mount points?
I'm curious about carbon fiber as an insulator. In my test a few weeks back I pointed a MAP torch ( ~3700F ) directly at a 1.5mm thick sample. The binder obviously burned immediately. After about 2 minutes though the binder was gone and the face of the carbon fiber sheet was bright red, but the rear didn't show any color change. Any chance this is part the setup you're testing out?
Seems like the weak link when dealing with high temperatures is the epoxy in the honeycomb.
I guess you will test kevlar, Aerogel and/or Starlite(by NightHawkInLight version ) or a combination of the three🤔
Just search for intumescence for Starlite like Materials
Is there an estimated time frame for exhaustion (Burn/Melt/Fall-Off), of all/most combustibles, up-front?
The test at 0:43 looks like a secret material you didn’t show here ...?? What other materials did you test and is there going to be another video ?!
I am very interested to see a real test of a through-firewall connector or a cable guide or a fuel line... These are the real weak spots, in my opinion. Have you tested some foaming paint systems, like FlameRest?
My concern would be that a bulkhead fitting would become a gaping hole once the hose or wire insulation melted!
For a lightweight firewall material, I'm imagining something like a Starlite-esque material a la NightHawkInLight
I hope you see this but i realize its an older video...but why not use inconel? Im not fimiler with airplane specs but i have a motorsports background and anything high heat high melting point low thermal transfer ect inconel was the go to...not on the list??
Why not use aerojell. It is very light & a great thermal insulator?
I'd like to see a good test with Basalt fabric. I think it's melting point is 2600°F.
What about structural stability and crash resistance? Isn't that something the firewall does too?
Example scenario, you are landing and a weel fails because of a puncture. Plane gets hard to control and impacts the front with a slight angle and hot engine... fuel pump still running? Arms broken from the impact? How do you get out? Are you still protected from the fire?
I'd buy a dark aero mashmallow man t-shirt.
With flames!
I'd check Teknofibra material, used plenty in Motorsports
Can the Ceramic Heat Shield Blanket, at 1/8", be Doubled in thickness?
Compare Marshmallow Man, against Nut Man, and a Woods Metal man! (Sprinkler Plugs!)
I would suggest, the Temperature, 1" to 2" from the Firewall on the Ties side, should not exceed 110°F, but Ideally, be kept under 85°F, in a Full on, Forced Air, In Flight Engine Bay Fire!
Aramid composite is the secret you've got under test?
The colour discrepancy is because the camera pics up near infrared and some cameras also can't differentiate between visible and infrared light
Can you use aerogel for insulation?
Have you looked at Aerogel? It has huge insulation while being super lightweight.
I want to aerogel my house.
Get a few space shuttle heat shield tiles. John Manville makes them......cost.......I really don't know
Have you considered an intumescent material for the firewall?