Explaining the Delta Rocket Fireball - Kerbal Space Program Doesn't Teach....
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- čas přidán 13. 01. 2018
- Every time a Delta IV launches people inevitably ask if the rocket consuming fireball is supposed to happen. The answer is yes, this is caused by the rocket purging its engines with hydrogen before letting the hydrogen/oxygen mixture into the combustion chamber. But there's more to it that that of course.
- Hry
I like how the first 5 seconds of any launch always look like it's going terribly wrong. Makes it exciting! "Oh boy big fireball. Oh nope everything is fine."
They have to make it exciting to keep people interested ;)
Well, except for the F9. Those are pretty sedate next to 'accidentally light yourself on fire every launch'.
@@benjaminrich9063 then they set themselves on fire in order to return to earth safely
Wait, 64 tons into low earth orbit... well the M1 Abrams can be pressure sealed against contaminants... SPACE TANKS
I wonder how much delta-V a cannon shot imparts...
Spy Crab ok I'm with you. To navigate in the vacuum of space, the m1 could fire in the opposite direction of where it wants to go.
Containment Failure about 1500m/s
Space tanks for our space force! I love it!
Sebi One: The latest version (M1A2) can carry 42 rounds for its main gun. The M829A3 round weighs about 22kg, including the propellant, but since the combustion gases also shoot out of the barrel, we can include that mass in the calculation. The muzzle velocity is 1555m/s. If you do the math, that translates into a delta-V of a measly 23m/s for the tank itself. Not much manouvering gonna happen.
In terms of specific impulse, that's only about 158s, which means that tank guns are pretty bad rocket engines.
Fun fact, Scott's car also produces a giant fire ball at first start up.
I do that also after snacking on burritos
Terry Wilson no, his is just an interplanetary Rocket
Terry Wilson not on start, but after an accident and with water
"my other car is an interplanetary rocket"
I produce a giant fireball at startup too!
Still think they should have skipped 4 and gone straight to 5. Then they could say they have the most DeltaV of any rocket company :p
lol
AIRHORN NOISE AIRHORN NOISE AIRHORN NOISE!
Get out
They should rename Vulcan to Delta V.
Ha. Ha. Ha.
Great video man(ley). I learned a lot!
Nice
HI DESTIN :D
Laminar flow FTW!
That was a very man(ley) pun.
Haha nice one
I think they just like to caramelize their rocket before launch... :P
David Wei Space Crème Brûlée !! 😂
David W. - LOL Too dang funnny! HOw bout: rocketeer butt flambe'
yum 😎
Lol
Because it's surface is covered by Marshmallow, err.... Foam!
the tastiest rocket ever built!
Toasty - and tasty!
In fact, it is cork, not foam. Or at least a material that contains cork as the main component.
You are right. I read this in someone else’s comment an did a quick research because I was intrigued by the unusual choice of material and wanted to know more about it. All I could find was “Cork insulation in NASA’s Delta project”. But it’s used to prevent excess heating from aerodynamic friction.
www.cork-2000.com/en/141/Cork+news/Cork+insulation+in+nasas+delta+project.html
"its surface". You don't say "by the seat of I'm pants" either. My - your - his/her/its - our - your - their.
All im thinking about here is how pissed off the guy is who paints the orange sheathing when that happens, lol.
NkkkkjbnTookster ggggggg
Am 99% sure the orange color is the natural color of the insulating foam. Paint adds weight. Is the reason why the first Space Shuttle launches had a white tank - they very soon switched to no paint.
Thats a result of it _not_ being painted.
@@Unknwn-fw3po _underline_
10000000000% pissed off;)
Man... I love how the "if" in regards to the Falcon Heavy is now a.... "Now" is so pleasing. I remember when I was fighting the last battle of the Fountain war in my Naga, I never would have thought a rocket's first stage would ever land in order to be reusable. Scott Manley, you are a future legend. Technology is so beautiful it makes me want to cry. TY.
nonetheless, it's always prudent to check one's stagin'
Nothing worse than some random upper engine lighting up for no reason and you have to revert, only to do the same mistake again because you did it on the fly instead of in the VAB... grr
Or just add more struts.
Relatable
Somethings gone wrong, they seem to have completely forgotten the re-entry & landing staging!
Enigneering Report: Critical: No Parachutes!
Wow, those shots of the Delta Heavy rising from behind a hill, then flying past the moon. Epic.
If they make a Delta V it's going to be extremely confusing
HAHAHAHA
Technically the delta 4 has five rockets in its family. They totally should have named one Delta V.
How much delta v does the delta airlines delta v have?
luckily and sadly they wont, they will be using vulcan
@@jacko4932 Yeah, rip hydrolox rockets, theyre too expensive when being expended. Almost all next gen rockets that arent planned to be reusable will have SRBs :(
Thank you for the insight, not only into the fireball, but also the fuel/oxygen ratios, and the color of the exhaust plumes. Good stuff!
It's just like lighting an oxyacetylene torch. You ignite the fuel, which gives this bright yellow sooty flame, then you add the oxygen.
I was taught to open both valves at the nozzle about one-quarter turn, acetylene first, and then ignite the flame. It ignites easily and you don’t get this soot development at all.
Sort of. Except that hydrogen doesn't soot.
Yes, but I'm not running the torch on hydrogen. It doesn't make a bright yellow flame, either.
Except that the fireball burns your eyebrows off every time you light the torch.
then don't light your torch off your cigarette....nupty
So...it purges itself with fire before doing its duty?
*The God-Emperor of Man Approves of this*
Scott, you bring rocket science down to earth
Vlad Tchompalov that comment needs to be pinned
*de orbit
thats everyday astronauts job
@@kolba1253 mhm
Jan Kalbarczyk i was gonna say that
God damn, rockets are cool
depends on the part. some are quite hot.
flippynl badamtish
And that's why I am building a sugar rocket in May. With camera in it :) Expected fly height to be at least 100m in case of two stage burning engine
But SpaceX rockets are cooler.
Bin Ou Yang I still question how carrying extra fuel to perform a rocket landing (increasing weight and therefore reducing payload) is anywhere near as efficient as just.. using fucking parachutes that don’t need shit tons of fuel to work.
CHECK YO STAGIN' NASA!
It's a ULA launch.
welp. ayylmao
KSP at NASA. You know they use it to plan missions.
Long video, or multipart video about currently in use and in production rockets would be great! Also occasional update videos on rockets launched, what was their payload, etc. would be really awesome. And there is not detail too small to talk about. Really enjoying these videos!
ULA builds the Delta in my area. I live in Huntsville, Alabama. We are getting a Blue Origin engine plant as well as a new Rocketdyne engine manufacturing facility too.
Greg Cooper
Decatur, to be precise.
Rocketdyne always sounds to me like it belongs in Terminator 1 or 2. 😀
Greg Coopehhh
I went to grad school in Huntsville years ago. Great town.
I regret leaving.
My father works as an aerospace engineer on the Delta V with ULA out of Decatur, AL. They just had their 30th successful launch out of California a few days ago.
You should make a video about human rated a rocket
I agree, that would be cool!
What rocket would be human rated according to NASA standards?
Seriously, while there are some general assumptions of what human rating means, none of the launch vehicles which have carried NASA crews into orbit have ever met their own human rating guidelines. The Soyuz and even the Shen Zhou spacecraft would have failed too.
The fact that the Falcon 9 and the Atlas V will be technically human rated when they fly to the ISS is just a matter of perspective. Scott Manley's take on this would be entertaining to watch though.
Yes, yes! I too would love to see what it takes to "human rate" what amounts to, effectively, a round of long range artillery. ^_^
My grammar is so bad but people still understand what I'm trying to say ,😂
GlanderBrondurg, as long as it meets NASA's 99.999% acceptability. Thankfully the Boeing Starliner and the SpaceX Crew Dragon has launch escape systems for the event that 0.001% was to happen.
Thanks for the video! This was the first Delta 4 launch I watched live, that was clench-worthy.
Thanks for the info - very much appreciated. I was at VAFB for the Delta launch on Wed and Thurs., but had to get back home and missed the Friday launch. On Thursday, I had found a great vantage point to observe the launch - and ran into a couple of retired VAFB 'rocket dudes' - and heard them discussing this very issue! Thanks again...
The Solar Probe launch was beautiful, the Plumes were impressive, and now I know the science behind the display. THX 👍
Huh. Thought it was something more akin to the Blackbird pissing fuel before the heat generated from the high speed caused it to expand and seal. TIL!
lol. That design is hilarious. I mean, I'm sure they wouldn't have done it if they had a choice, but still, the fact that your aircraft leaks fuel whenever it's not flying fast enough for thermal expansion to seal all the holes sounds really dumb.
KuraIthys better than your fuel tank cracking open when flying at high speeds due to expansion, I assume that’s what would happen at least
A few years back I was playing a videogame called SpaceChem. It's a sort of finite state machine contextualized as a videogame. The solution I was most proud of involved solving the problem randomly then checking if I had solved it correctly. It was a massively wasteful but elegant solution.
I feel some kinship with those SR-71 designers. "Our solution leaks fuel constantly until we achieve supersonic flight but jet fuel isn't that expensive so we will just constantly refuel until the plane leave US airspace and goes supersonic."
That animation of falcon side boosters landing at once looks a lot like the one we saw last week for real.
all that mean is it worked as planned and calculated. Not out of the ordinary really...
However, the FH animation showed the center core returning to land, which never made any sense. The barge is the only place it makes sense to land the center.
Sweet vid. Informative and interesting. The first time I saw the fireball, I just figured it was a non-important anomaly. Non-important, in that it did not halt the launch in any way. Knowing that the fireball is actually built into the launch sequence... that's just some beautiful design, right there.
Love all your video's Scott!
That was super interesting! One of my favourite things about rocketry is that there's a neat reason behind every single detail. On another note, will we be getting more "going nuclear" episodes?
Yeah in the last one he mentioned the next nuke episode will be going into enrichment/reprocessing.
I wrote a tweet and promptly removed it because you already gave the answer. But thank you very much for making the video anyway!
I already figured out what must be going on with the startup fires but you won me with the explanation of the red flame colour. Great video. Thanks man!
I love that you explained the clickbait at the start of the video!
Much better than me just scrolling for comments for the conclusion or timestamp.
Where is the MechJeb module on this rocket located?
Probably clipped inside vessel somewhere, so it doesn't impact its aesthetics.
Integrated with the control core.
Or maybe the one playing is just playing with pure vanilla. :0
porkypine no this is rss
+Bzorlan This is RSS/RO, but MJ is probably also installed
i disagree, you should ALWAYS advice people check their staging
Thanks, Scott. I was in the satellite business for a few years and we used to get this question a lot. Really well explained.
Interesting and very informative videos Scott. Was just wondering about that after seeing the Delta 4 launch at Vandenburg.
i light myself on fire at the start of every launch as well
Normally when flames lick the side of an object, the resulting black smudge is from tiny particles of solid carbon deposited as a biproduct of combustion. When burning hydrogen, there's no carbon lying around. Why do the tanks blacken? Is it a result of the paint itself burning?
It's not paint - it's foam. So it's very easily burnt.
Thanks!
There is black smoke though so I wonder if it's the mixture of hydrogen to air (rich mixture) and carbon is the byproduct
I think that'd only happen if they were using the CO2 in the air as an oxygen source. I'm no expert so I could easily be wrong about that.
I don't think they could be doing that because of how much energy it takes to break the bonds in CO2, we fuel most of our world on the energy released by those bonds forming and to break them you need at least as much energy as it released in the first place.
Secondly, I don't think there is enough CO2 in the atmosphere to account for that much soot that quickly in that local of an area.
I was assuming that the soot was coming from the rocket coating, apparently foam, and the graphite on the cones, and perhaps there is some incidental litter; they might burn of plastic seals on things that need to be kept clear of any moisture or dust or something. Then there's leaves and shit on the ground maybe or even small animals that entered the fireball zone.
No evidence for any of that, just my thoughts.
yeah, agreed. sort of what I was thinking and trying to say
It was the first Delta rocket that i've seen being launched and i really thought that it almost caught fire after all those problem checks and rechecks. Thank you for your explanation, Scott!
Thank you Scott for explaining in such detail about the Delta Rocket fireball. To me this is really some fascinating stuff.
Scott, why didn't the Shuttle exhibit the same sort of fireball?
Both the Delta IV and Shuttle used sparklers (or ROFIs / Radially Outward Firing Initiators). Were they placed differently on the Shuttle so that the hydrogen lit earlier? Is it that the RS-25 (SSME) used staged combustion, so all the hydrogen exited the nozzle and was easier to ignite locally than with the RS-68 where it also exits the gas generator exhaust / roll control nozzle? Or does it have something to do with the Delta launching dry while the Shuttle used a water deluge system?
If you look at footage from the launch crawler, the sparklers were set well below the SSMEs, so that hydrogen that did combust due to this pre-ignition sparking would do so in the exhaust area and not flame up around the shuttle itself.
Amazing video Scott! What do you think about all the media talking about Zuma, they all asume that Zuma Indeed failed, why is that, I mean why almost every nes about it confirm that Zuma is Lost but acctualy there is not a official claim about that?
There are 2 news outlets who independently received reports from sources in congress that the mission was lost. That is all that is known about it. The fact that no one appears to declare the mission a success (which is allowed, even with the most classified of missions) also goes to show that something did not go according to plan. Since SpaceX claims the F9 performed as planned we can only assume that something went wrong after SECO. The most probable cause at this moment is that the payload adapter (usually built by SpaceX, but in this case by the customer) failed to seperate the payload and because they did not see a way to release it the second stage did a deorbit burn with the payload still attached.
Zuma is a funny story imo.
SpaceX did everything as they were supposed to do - they successfully delivered the payload into orbit. What happens after that is a different story as there is no official information and at the recent briefing the US government well - lets say it like this - they didn't do their job at all.
Or maybe... they *want* us to believe that Zuma is indeed lost... for the safety of whatever mission it was designed to carry on?
The odd thing is, if F9 performed nominally, Zuma should be in the correct orbit. Which means there is no reason for it to have reentered. So either the government is trying to hide it (could be very advantageous) or somehow the spacecraft's propulsion system went very wrong and deorbited it somehow. Besides that I can't imagine why it would reenter.
maybe zuma has some stealth technology so you can't see It, so they deorbited space x second stage so it doesn't follow Zuma in the same orbit
Id love to hear more about the rs68, seems like a very interesting if not short-lived engine!
Great content Scott even 5 years ago!
Love hearing starliner's first launch THIS year 😅😅😅
Really like this kind of videos, great job
4:50 I had to run that back because it sounded like he said "human cattle" .
"Human catchtel"
Cody's lab had a video with a check yo staging shirt on.
I saw that as well. Made me giggle like a little schoolgirl xD
Which one was it?
Love your videos, very informative and entertaining
Finally I can hear the details of the melody in the music! It bothered me for so long that I couldn't make out exactly what the rhythm and notes were. It's a bit more clear in this video.
If the RS-68 is more powerful than the RS-25, then why is the SLS designed to use four RS-25's? Is it for the improved efficiency, or just because NASA had a bunch of leftover engines after the shuttle program ended?
It’s because of ablative nozzles. The rs68s would get destroyed by the srb plumes. The rs25s will not
The core runs from sea level to almost orbit. They need engines that are efficient from sea level to orbit; which the RS-25 does spectacularly
Looking forward to Falcon Heavy
@3:24 & @3:30 ooohh my god so cool! Awesome camera angle shots man!
I wonder the same question when I watched the First Orion test on my computer after watching it moments before from the Indian River from when I lived in Florida just about 20 15 minutes from KSC. I could step outside and watch launches all the time it was pretty awesome
Can someone explain to a layman what Scott means when he says "fuel rich"? Does it refer to a higher ratio of hydrogen vs oxygen (ie. hydrogen is fuel and oxygen isn't?) or something else?
Yes. Technically oxygen is not referred to as a fuel in rocketry - it's an oxidizer. The other part of the mixture is referred to as the fuel. The two (or more) components together are referred to as propellant. Very pedantic, sure, but it matters in those kinds of things!
In this case, Fuel is LHy, Oxidiser is LOx. A balanced ratio is 1:8 by mass. Fuel rich uses more LHy. On the other hand, Oxidiser rich uses more LOx.
Fuel rich (aka rich mixture) means the same for a rocket as it does for a car engine: Pumping more fuel into the engine than it can burn with the available oxidizer.
This is done for similar reasons: In a car engine, making the mixture too lean makes the combustion much hotter, which puts a lot of thermal stress on critical parts such as exhaust valves and spark plugs. In the rocket, burning too lean also means burning too hot, which can literally melt the combustion chamber and nozzle if the temperatures are not kept under control.
Cooling in a rocket is often described as "regenerative", which basically means that the fuel is pumped through a layer surrounding the combustion chamber and rocket nozzle, preventing those critical parts from overheating. This has the convenient side-effect of preheating the fuel, vaporizing it before it is injected into the combustion chamber to be burned.
There is of course another reason for running the rocket engine fuel rich, which is to improve the specific impulse, a measure of rocket propellant efficiency. This is about exhaust velocity - the faster this is, the more thrust the rocket generates. But for any given temperature, smaller molecules travel faster than larger ones.
Hydrogen is just about the smallest molecule possible, so in a rocket using hydrogen as the fuel, you want to have a decent proportion exhausting without being burned by the oxygen, which would convert it into water vapour, a much heavier molecule. Though of course you do have to burn some of it to heat up the rest, hence the rich mixture.
This also works for rockets burning kerosene (aka RP-1), which is a hydrocarbon. Oxygen is used as the oxidizer for this as well, so a lean mixture would produce water vapour and carbon dioxide. Running this fuel rich means that some of the carbon is oxidized to carbon monoxide, a smaller molecule, meaning greater exhaust velocity and higher specific impulse.
I am curious about the black smoke after the fireball
Erm... it's fire.. the foam changed color... putting one and one together suggests something gets burned during this action, which results in black smoke usually
sooty smoke like that is almost always due to the incomplete burn of something with carbon in it from what Ive seen.
That'd be burning foam. Kind of gross.
Mush V. Peets don't cook your marshmallows in that fire.
Dimitri Wu flame retardant paint in red areas.
Excellent explanation! Thanks for the video.
Great stuff as always, Scott.
So they are new designed rockets that get built one time ,used one one time and then Thrown away ? Is that correct ? And if it is does it completely burn up or do they fall partially burnt back into the ocean ?
And rockets are awesome so thanks for your channel :)
Most parts of a space rocket are a one time use component due to the weight they have while empty, it's too much for parachutes to handle. Booster rockets on the other hand are light enough that they can be returned with a parachute because technically they are just a capped tube with a nozzle at the bottom for thrust and are packed with solid fuel to burn, not a liquid hence no need for separate fuel tanks in them.
You shouldn't call it a new designed rocket because the design is the same for each one but they do build a specific rocket for each Mission because it is expendable. Depending on the mission profile the components will either fall back down and burn up in the atmosphere or the land in whichever ocean is along the trajectory
Nah, that was intended to give it that trendy reused rocket look. 😂
That fireball always freaks me out! Thanks for the explanation.
That fireball is way larger than I would have ever expected. Not too long burning, but it's huge.
first video I saw of you're, subscribed
Stoichiometric, not stoic metric. Jesus died on a stick and paid for that mistake, but he wants you to get it right anyhow.
The more comments i read, the angrier i get at peoples ignorance, my new years resolution is to stop reading youtube comments
Watch Idiocracy and tell me the world isn't getting dumber.
Only have to watch the newz
I never watch the news. I'm always amazed when I walk into somebody else's house and they have the TV on on the news constantly.
+Exodarion Good luck with your commitment ...
Brawndo has electrolytes.
I think the awesome voice, combined with awesome rockets, makes this my favourite space channel
Came here after NRO-44 Launch Abort. Great info!
ULA forgot to check their landing stage :-D
They don't have a landing stage, that is only the falcon used by SpaceX
@TheSpaceGamer that's the joke. SpaceX are doing it right by making their stuff reusable, whereas the American government is still following the throw-away approach, as they do with everything else.
R/whoosh
... Shouldn't you always check your staging?
Thanks for the expalanation! My heart stopped when I watched this live. Now I understand.
Thanks Scott for helping me understand rocket stuff
Scott, there are so many flat earthers these days, unfortunately my family included, what's your take on the flat earth conspiracy?
People who believe in that nonsense need a more, shall we say, fully rounded education ...
JSparrowist I feel sorry for you, man.
I don't believe the earth is flat. Just to clarify. My family does though. =(
It is because school don't teach the whole story. They teach few things and stuff but that's it. Next year they learn the same thing. They aren't shown physics, science in general, and the earth at a young age. The, "it's too complicated" is really stupid. Math is really "complicated" for people yet we learn it. It's this that cause them to be locked in their own psedo science world, which causes them to believe in the flat pizza planet.
Show them this minute long video. czcams.com/video/LSrL4xIQT7E/video.html
It's the curvature of the Earth demonstrated with a high-zoom camera. The creator of the video, Soundly, zoomed in on the horizon with a Nikon P900 camera, demonstrating the causeway curving over the horizon.
Check out some of the other things on his channel if you want, your family might want more proof that he's not a "NASA shill government slave" like Flat Earthers always say.
Hope your family can find themselves in reality soon.
So why didn't the Saturn v do this?
Because its first stage used kerosene and oxygen, not hydrogen and oxygen.
Saturn V's first stage fuel is liquid at room temperature (it's kerosene).
The kerosene fuel of the Saturn V will just fall straight down and ignite below the rocket, while the hydrogen on the Delta IV will rise quickly as it is much lighter than air. Simply put.
If you watch a Saturn launch with cameras aimed at the base, you'll see a smaller firball rise around the base of the rocket. Then the turbopumps get up to speed and the firball is sucked back down into the pit by the thrusting fuel travelling downward. See, for example, czcams.com/video/DKtVpvzUF1Y/video.html
I have seen a slow motion film of a Saturn V launch, taken from close to the booster. Everything catches fire... But it takes time after the ignition before the smoke and flames get sucked back down. Kerosene doesn't burn well as a liquid, though not as hard as diesel to get ignited..
I could listen to you talk about rockets all day.
Thanks for this video, dude. I just about had a heart attack when I saw the fire creep up the rocket during the live broadcast. After the launch was apparently ok, I thought maybe the sparklers hadn't lit and so the excess hydrogen didn't burn up. Interesting to learn that the engines spew pure hydrogen at startup before the mix happens.
hey scott could you please play the game "spaceflight simulator" it`s a mobile game for android and ios i can`t make a rocket that can return from a planet.
I can’t really do mobile games because of my day job. Besides those guys ask people to make a 5 Star review to unlock content and that’s straight up dishonest (it works if you give it a 1 Star review)
Scott Manley i understand...thanks for replying so quickly
I have never seen a game that tells you (even implicitly) that to unlock content you must rate 5 stars.
We might however have to advice Spacex to check their staging, considering the isues with ZUMA ;)
All of SpaceX's staging seems to have worked fine, if anyone messed up, it was Northrop Grumman. As far as we know, they also built the payload adaptor, which is what (allegedly) failed to separate.
top kek na, that satellite is up there, it's just a great way to get everyone to ignore it if they say it failed...
Because off course the people you want to hide it from are not capable of tracking a satellite and the public isn't going to be pissed you lost a billion dollar piece of equipment.
for all we know Zuma is up and running as intended as there are no contrary information - and i mean confirmed official information and not some bullshit newsstory.
the payload was confirmed to be in orbit - correct position, trajectory and all that. But now somehow the US government supposedly doesn't know what is going on... yeah right.
Truth Undenied arguably this caused more attention to be paid to the satellite, so if that's what they were going for, BACKFIRE!
Only now this video reaches my timeline... Very interesting Scott! Im a fan of your work :-)
PS, the heavy was a success in the right way ;-)
This is great knowledge!! Thank you Scott! 🙌🙏
In piston-powered general aviation aircraft like Cessnas, Pipers, Mooneys, or Beechcraft we use engines made by either Continental or Lycoming. Some are carbureted and some are fuel injected. As we fly at higher altitudes the fuel/air ratio becomes "richer" because the amount of air pressure decreases as we climb. So in order get the best efficiency, we have to reduce "unscrew" the mixture control to "lean" the amount of fuel going into the engine so that it remains at a constant fuel/air ratio.
Pilots have the ability to "over lean" the engine. That is, we can reduce the amount of fuel to the point where we create too lean of a mixture and the engine starts to lose power. If we go too far, the engine will quit, but the propeller will still spin at high rpm's. All we have to do is push the mixture control in a little and the engine will start running again. It's not scary for a pilot but we don't intentionally do in with passengers because it scares the crap out of them.
We can save fuel by overleaning the mixture, but we lose engine performance as well. Some pilots fly on the "lean side of peak" using a power curve chart in order to save fuel, but in turn, lose some performance. It's a smart thing to do when you have a good tailwind. We take advantage of mother nature rather than waste fuel.
But the point is that most pilots fly on the "rich side of peak" meaning that the fuel/air mixture has slightly more fuel than necessary to create maximum power. The peak mixture would be the hottest, and not best for the engine's lifespan. But a slightly rich mixture gives the best performance without making the cylinder head temperatures too hot. We are taught about the stoichiometric mixture performance early on in our pilot training.
It seems the rich side of the power curve is also what rocket scientists prefer as well, according to this video. "Run it rich" is the term of art.
Another perfect video. Thanks Scott.
Very informative, thanks.... keep up the good work.
Those two charts at 0:24 and 0:44 are fascinating. I'd enjoy a short video on each!
Hmmm...the right level of nerdy stat stuff but told in a compelling and dramatic way. The moment you feel overwhelmed by equations he brings the context. I have subscribed.
Such a great channel.
I was hoping you would explain this!
Great explanation scott, thank you.
I posted your video to R/ space and got you about 5k views, great content scott ! :)
Oh... great video btw... I always wondered about the big fire ball for the Deltas.
3:43 - I nerded out when the Delta passes in front of the moon, great images.
Great explanation as always!
Nice vid Scott :) Good explanation
Amazing video ! Thanks for sharing.
Hi Scott--I have taken to watching your stuff with interest. You do a good job. For the purposes of this video explanation, I would like to offer the following modifications: First, regarding the expulsion of H2 from the RS-68 during engine start--the start sequence on the Delta 4 was not the start sequence we were ultimately intending to use. The start sequence currently being used was one that was put together for the purposes of initial development testing, and was intended to ensure that the engine's H2 system was in thermal equilibrium before any O2 was introduced. The purpose of this was to preclude any H2 flow oscillations, which are present BIG TIME in the SSME during start, and which render the SSME's start sequence a very delicate matter. We were still 'stinging' from the SSME start sequence 'debacle' when RS-68 start was being scoped out. It was our intent to 'clean up' the 68's start sequence as development proceeded, to ensure minimum propellant consumption during start, but time/funds were not available.
Second, regarding your plot of Isp versus engine mixture ratio--we should remind ourselves that the 'optimum' mixture ratio for Isp is a function of the engine chamber pressure. While your plot is valid at RS-68-level chamber pressures, lower Pc engines (such as the original J-2) have lower 'optimum' mixture ratios. Higher Pc engines (such as SSME) have higher 'optimum' mixture ratios.
I absolutely love your science video's.
This is great info. Had never seen a Delta launch before and thought something had gone wrong.
Man, that scenery around that launch location is so nostalgic. I hated walking that fenceline
love your videos. also love the intro music very much. i wish someone will make a 10 min loop version of it. :D
At 3:44 what an incredible freeze frame, passing the full moon. Wow!
As usual: great report!
One topic that I have not seen covered a lot is about the rockets chassis. The framework and support structure. Specifically how the engine is mounted to the rest of the rocket.
Interesting and informative, very good! 👍
thanks scott, really informative. oh i did wonder about the fireball at launch!