Delta IV Heavy Launch from Vandenberg, California

solrey

Senior Member.
I was impressed by the fireball at ignition. Seems like a lot of transient hydrogen around the base. Also, it appeared there was some flame around the edges of the base as it initially climbed out. Seemed strange.

http://www.spaceflight101.com/delta-iv-heavy-nrol-65-launch-updates.html
 

captfitch

Senior Member.
Something I always wondered, do you ever have to adjust trim because lots of passengers are moving to one side if the plane? I've wondered if they simulate an event like that with ballast barrels.

No, even if every passenger moved to one side, they are only moving a little ways in relation to the center line so their collective arm wouldn't be very long. Fuel, on the other hand weighs a lot and could potentially have a long arm depending on fuel level in the wings. But only under rare circumstances (think engine failure) would there be an opportunity for a fuel imbalance. Fortunately the ailerons are way out there and have a very long arm so it takes a relatively small aileron trim change to keep the plane from turning under that condition. On my aircraft the limitation for fuel imbalance in flight is 1100 pounds. So left side could weigh 7000 pounds and right side could weigh as much as 8100 pounds. Seems like a lot but the plane weighs over 50000 pounds. Interestingly the for/aft balance limitations are always measured in inches and my aircraft has to maintain a balance within 31 inches at all times even though the whole plane is nearly 100 feet long.
 

justanairlinepilot

Senior Member.
No, even if every passenger moved to one side, they are only moving a little ways in relation to the center line so their collective arm wouldn't be very long. Fuel, on the other hand weighs a lot and could potentially have a long arm depending on fuel level in the wings. But only under rare circumstances (think engine failure) would there be an opportunity for a fuel imbalance. Fortunately the ailerons are way out there and have a very long arm so it takes a relatively small aileron trim change to keep the plane from turning under that condition. On my aircraft the limitation for fuel imbalance in flight is 1100 pounds. So left side could weigh 7000 pounds and right side could weigh as much as 8100 pounds. Seems like a lot but the plane weighs over 50000 pounds. Interestingly the for/aft balance limitations are always measured in inches and my aircraft has to maintain a balance within 31 inches at all times even though the whole plane is nearly 100 feet long.


I find it interesting about your specs. My aircraft weighs up to 85,000 lbs yet can only have a max fuel imbalance of 800 lbs. maybe it has to do with the spoilerons and aleron systems. Different wing designs?
 

Ross Marsden

Senior Member.
To get contrails, you must achieve water saturation at some point. At water saturation (RHw=100%) in our current atmosphere there are cloud condensation nuclii present, so condensation ensues. In the proposed perfectly clean atmosphere with no aerosols what so ever you need to get to quite high super saturation before it will occur spontaneously... 120% 130% 140%. You would still get them but that mixing line has to be deep into the saturated )cloud) zone. https://www.metabunk.org/threads/us...mages-and-infographics.1007/page-2#post-59756

As justanairlinepilot more or less says, supercooled liquid water will spontaneously freeze at or below about -40°C. And in an ISSR you will have persistent contrails.

Other stuff (not water) in the jet exhaust does help the freezing and condensing processes to an extent, but these are not essential. Those will occur anyway.

The main problem would be to achieve high enough super saturation with respect to water during mixing of exhaust with environment to get condensation to occur in the absence of CCN (in the proposed perfectly clean atmosphere).
 
Last edited by a moderator:

cloudspotter

Senior Member.
I'm a little confused Ross because it's ice nuclei that are required and I've seen you state that the air is essentially clean of these which is how ISSRs can exist. Can you clarify please?
 

Jazzy

Closed Account
I was impressed by the fireball at ignition. Seems like a lot of transient hydrogen around the base. Also, it appeared there was some flame around the edges of the base as it initially climbed out. Seemed strange.
There would be all of those strange manifestations you so closely observed.

The fuel is passed through the rocket housing and enters the chamber through perforations so that a liquid film travels down the inside surface of the motor in an unburnt state. If the actual flame contacted the inside surface of the chamber it would be game over.
 

Mick West

Administrator
Staff member
I'm a little confused Ross because it's ice nuclei that are required and I've seen you state that the air is essentially clean of these which is how ISSRs can exist. Can you clarify please?

Here's my understanding, which might be wrong:

There's three key distinctions:

Homogeneous vs. Heterogeneous nucleation (for both condensation and deposition)
Ice supersaturation vs. Water supersaturation.
Ice nuclei vs. Water nuclei (cloud condensation nuclei).

Ice nuclei and water nuclei (CCN) have different physical properties. Ice will deposit on ice nuclei, but not on water nuclei

Ice nuclei are are not required at -40C, as water freezes without them (homogenous nucleation of ice within liquid water). However you need some liquid water to start off with.

For a normal contrail, you'd need RHw > 100 % (temporarily), and the water condenses on the CNN, this then freezes as it's -40C, which then gives you ice, which is an ice deposition nuclei.

If there are no CCN, then the water will still condense out homogeneously at very high supersaturations.

ISSR can exist with lots of CCN but no ice deposition nuclei.

Then I think there's also a distinction between an ice deposition nuclei and a ice freezing nuclei?

This is why it's hard to explain contrails in depth to the chemtrail folk. These distinctions are inaccessible to their understanding.
 

Jazzy

Closed Account
The partially-burnt fuel molecules and soot particles in fanjet exhausts contribute countless billions of seeding instances per meter of forward flight. There's no need to get very worked-up about whether it's ice or water in any particular circumstance. There will always be an excess of "seeds".

You can bet your boots that a formed trail is falling through air that is busily reducing its saturation to below 100%.

https://www.metabunk.org/threads/us...mages-and-infographics.1007/page-2#post-59756

The diagrams you pointed to, Ross, were a great improvement on the ones I had seen previously. Thanks.
 
Last edited by a moderator:

captfitch

Senior Member.
I find it interesting about your specs. My aircraft weighs up to 85,000 lbs yet can only have a max fuel imbalance of 800 lbs. maybe it has to do with the spoilerons and aleron systems. Different wing designs?

Sorry, 50000 is a general OWE (what we used to call BOW). MTOW is actually 99500. As the total fuel on board drops below 21000#s the max imbalance drops to 600 in flight. And the whole wing is different than any RJ, much larger and more spoilerons.
 

captfitch

Senior Member.
Here's my understanding, which might be wrong:

There's three key distinctions:

Homogeneous vs. Heterogeneous nucleation (for both condensation and deposition)
Ice supersaturation vs. Water supersaturation.
Ice nuclei vs. Water nuclei (cloud condensation nuclei).

Ice nuclei and water nuclei (CCN) have different physical properties. Ice will deposit on ice nuclei, but not on water nuclei

Ice nuclei are are not required at -40C, as water freezes without them (homogenous nucleation of ice within liquid water). However you need some liquid water to start off with.

For a normal contrail, you'd need RHw > 100 % (temporarily), and the water condenses on the CNN, this then freezes as it's -40C, which then gives you ice, which is an ice deposition nuclei.

If there are no CCN, then the water will still condense out homogeneously at very high supersaturations.

ISSR can exist with lots of CCN but no ice deposition nuclei.

Then I think there's also a distinction between an ice deposition nuclei and a ice freezing nuclei?

This is why it's hard to explain contrails in depth to the chemtrail folk. These distinctions are inaccessible to their understanding.

These distinctions are hard to understand for anyone.
 

Mick West

Administrator
Staff member
These distinctions are hard to understand for anyone.

Here's the Encyclopedia Britannica's attempt, turns out there are three types of ice nuclei.

http://www.britannica.com/EBchecked/topic/41364/atmosphere/261458/Mountain-barriers#ref952960
 

cloudspotter

Senior Member.
Cheers guys, I'm glad I asked o_O

I shall attempt to understand that better when I've more time.

I don't know, just as I think I'm getting to grips with it.....
 

cloudspotter

Senior Member.
...it wriggles away. LOL

One thing I don't think I've ever quite managed to grasp is the continued growth (not the spread) subsequent to the the formation of the contrail. As I understand it the ice crystals grow and fall and are replaced by new crystals using up the available water vapour, but how are these new crystals forming? Or have I picked that up completely wrong?
 

Mick West

Administrator
Staff member
One thing I don't think I've ever quite managed to grasp is the continued growth (not the spread) subsequent to the the formation of the contrail. As I understand it the ice crystals grow and fall and are replaced by new crystals using up the available water vapour, but how are these new crystals forming? Or have I picked that up completely wrong?

Generally all the crystals form during the first few seconds. They fall at different rates based on size.
 

Ross Marsden

Senior Member.
Yah, it's the same number of particles. There is a stupendous number of them per cu cm. The particles are growing in size with WV depositing on them (while the supersaturation gradually reduces). The optical depth (= visibility) remains more or less the same even though the trail is being stretched in the vertical by precipitation (falling) and in the horizontal by wind shear through the depth (vertical dimension) of the trail.
 

Jazzy

Closed Account
One thing I don't think I've ever quite managed to grasp is the continued growth (not the spread) subsequent to the the formation of the contrail. As I understand it the ice crystals grow and fall and are replaced by new crystals using up the available water vapour, but how are these new crystals forming? Or have I picked that up completely wrong?
They aren't "replaced". They just grow. Eventually they fall into warmer air where they sublime back to vapor, generally. As Ross says, it's the same number of particles. They begin with a microscopic size - far too small to see. And as Mick says they fall at a rate proportional to their size.

In slightly more detail, the ice crystals are in dynamic disequilibrium when they are growing, in dynamic equilibrium when they stop growing, and in dynamic disequilibrium (the other way!) when they shrink. Water vapor molecules are traveling both ways at all times. (Sticking and unsticking).
 
Last edited:

Mick West

Administrator
Staff member
In slightly more detail, the ice crystals are in dynamic disequilibrium when they are growing, in dynamic equilibrium when they stop growing, and in dynamic disequilibrium (the other way!) when they shrink. Water vapor molecules are traveling both ways at all times. (Sticking and unsticking).

Yeah, it's like the next level up in understanding, to consider what is actually going on at a molecular level. It's especially important in understanding condensation and evaporation - the dynamic constant exchange of molecules was a bit of an eye opener for me.

Is it the same for deposition and sublimation though? It would seem like you'd get a lot fewer molecules exchanged with ice/air than water/air at equilibrium (saturated vapor pressure)
 

Jazzy

Closed Account
Is it the same for deposition and sublimation though? It would seem like you'd get a lot fewer molecules exchanged with ice/air than water/air at equilibrium (saturated vapor pressure)
I'm sure you're right about a difference in rates.

Crystals form the way they do because of the electrostatic potential differences (water molecules have an asymmetric potential). I don't know which shape (sphere or crystal) favors deposition or sublimation/evaporation in either case. It's on the limits of my understanding, being a designer, neither a researcher nor a theoretician in this field.

There is a considerable difference between a snowflake and those hexagonal prisms that are formed at high altitudes and low temperatures. But the number six features in both.

I suppose that a part-formed crystal is "stickier" where it is incomplete... ...and that prisms are formed in less chaotically-moving air... ...perhaps... :)
 
Last edited:

cloudspotter

Senior Member.
:rolleyes:Distant chink of a penny dropping. I'd been thinking of the ice crystals 'growing' in the wrong way. It's existing ones getting larger rather than new ones forming.

Dear me
 

Jazzy

Closed Account
Yeah, it's like the next level up in understanding, to consider what is actually going on at a molecular level. It's especially important in understanding condensation and evaporation - the dynamic constant exchange of molecules was a bit of an eye opener for me.

Is it the same for deposition and sublimation though? It would seem like you'd get a lot fewer molecules exchanged with ice/air than water/air at equilibrium (saturated vapor pressure)
This link is informative: http://www.atmos.umd.edu/~stevenb/vapor/
 
Thread starter Related Articles Forum Replies Date
Mick West Debunked: Delta Lambda Compression General Discussion 16
Mick West Delta 5733 (DAL5733) Burning Fuel to Return to Airport Skydentify - What is that Thing in the Sky? 4
nickrulercreator Starman and the Falcon Heavy Current Events 87
JFDee Falcon Heavy First Launch - Vertical Rocket Contrail Images and Videos: Contrails, Skies, and Aviation 3
Jay Reynolds Debunked: Dane Wigington's- “Heavy Wet Snow” Is Now Often The Norm Contrails and Chemtrails 45
TEEJ Pentagon to launch task force to investigate UFO sightings - August 14, 2020 CNN Article UFO Videos and Reports from the US Navy 28
Leifer Spacex Dec 23 twilight launch, "looked horizontal" Skydentify - What is that Thing in the Sky? 18
Mick West Debunked: 'UFO Trailing Blue Smoke' over airport [Atlas V Rocket Launch] Skydentify - What is that Thing in the Sky? 13
Gridlock Atlas V launch - multicoloured 'contrails' Images and Videos: Contrails, Skies, and Aviation 2
william wiley Does Damage to MH17 indicate or exclude a Particular Buk Launch Location? Flight MH17 662
Chew Google Earth file of weather balloon launch sites Skydentify - What is that Thing in the Sky? 0
Jason Debunked: MH17: Supposed satellite video of missile launch [Fake] Flight MH17 14
Jason Evidence for the Buk missile launch site Flight MH17 24
Pete Tar Probably not Ison... (rocket launch remnant) Skydentify - What is that Thing in the Sky? 2
Critical Thinker US 'backed plan to launch chemical weapon attack on Syria, blame it on Assad govt' Conspiracy Theories 5
Oxymoron Norway Spiral. Was it Really a Failed Missile Launch or Was it HAARP (EISCAT) Conspiracy Theories 36
Des O High School Kids launch Weather Balloon Contrails and Chemtrails 8
Pogopoint99 Missile Launch General Discussion 0

Related Articles

Top