Centaur G/G Prime High Energy Upper Stage

GLS

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Many small meshgroups... Or by manipulation of the vertices.

OK it is possible, but it seems to be too much work for just 6 bellows, of which 4 are barely visible. But feel free to do it.
 

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OK it is possible, but it seems to be too much work for just 6 bellows, of which 4 are barely visible. But feel free to do it.

Ouch. :uhh:

I can do it, if DaveS does what I tell him. Otherwise, I agree on your effort-benefit analysis. :lol:
 

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Ouch. :uhh:

I can do it, if DaveS does what I tell him. Otherwise, I agree on your effort-benefit analysis. :lol:
I think the vertex manipulation is the way to go. It's easier than keeping track of alot of mesh groups.
 

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I think the vertex manipulation is the way to go. It's easier than keeping track of alot of mesh groups.

Yes, but I would suggest moving the work to the GPU for that, by doing the following: Replace the bellows by a simple cylinder and texture the walls of the cylinder with a normal mapped version of the bellows. Even a generic 128x32 texture should look almost as good as it is now.
 

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Yes, but I would suggest moving the work to the GPU for that, by doing the following: Replace the bellows by a simple cylinder and texture the walls of the cylinder with a normal mapped version of the bellows. Even a generic 128x32 texture should look almost as good as it is now.
Does the bellows cylinder need to have more than 1 segment? If so, how many?
 

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Does the bellows cylinder need to have more than 1 segment? If so, how many?

No, only one segment should look correct - when the texture is properly distorted then (which it should) it should look good enough. I only fear moire pattern there, but we would have a higher chance for those when animating many small triangles.
 

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No, only one segment should look correct - when the texture is properly distorted then (which it should) it should look good enough. I only fear moire pattern there, but we would have a higher chance for those when animating many small triangles.
This is what we currently have with the new accordion bellows. No moire patterns at all. And adding more sections to actual cylinder mesh would not increase the the chances as the sections are invisible to the texture.

CISS_accordion_bellows.jpg
 

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This is what we currently have with the new accordion bellows. No moire patterns at all. And adding more sections to actual cylinder mesh would not increase the the chances as the sections are invisible to the texture.

More sections means more work by us, on the CPU, that is not necessary at all. Rotating 2 x n vertices by a small angle is easy. every section more means more calculations and more CPU and more CPU-to-GPU-communication.
 

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More sections means more work by us, on the CPU, that is not necessary at all. Rotating 2 x n vertices by a small angle is easy. every section more means more calculations and more CPU and more CPU-to-GPU-communication.
Copy that. Anything else on the mesh side before I check the new G Prime CISS in?
 

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Copy that. Anything else on the mesh side before I check the new G Prime CISS in?

I could use some magic trick to identify the vertices of the bellows and map them to a mathematical model.

And could you provide maybe a simple single bellow + pipes on both ends mesh for development? This reduces the distractions.
 

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And could you provide maybe a simple single bellow + pipes on both ends mesh for development? This reduces the distractions.
By this you mean just one duct and one bellow in a single msh file?
 

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By this you mean just one duct and one bellow in a single msh file?

Yes, a simplified test article for developing the animation. I fear doing the development in the CISS mesh could mean that problems are hidden by the complexity of the CISS mesh.
 

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Yes, a simplified test article for developing the animation. I fear doing the development in the CISS mesh could mean that problems are hidden by the complexity of the CISS mesh.
The mesh is pretty simple. Each branch, LH2, GH2, LOX and GOX have three duct segments and three bellows. Each is numbered 1-3 with 3 being the closest one to the disconnect panel and 1 being on the bottom.

CISS_duct.jpg


---------- Post added at 03:43 AM ---------- Previous post was at 01:51 AM ----------

I have checked in the updated Centaur G Prime CISS. Once we that done, I'll update the G CISS.
 

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Would you say that this paper is a good foundation for creating a Centaur G test scenario for SSU?

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20150006820.pdf

Its about getting a Centaur G into Molniya orbit with three burns and describes a lot of the features possible with a Centaur G, like offloading propellant in flight. Sounds like a good challenge to test our Centaur G against a NASA simulation of it to me.
 

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Maybe we can temper those numbers a bit with actual facts as the Centaur G Prime did end up flying on the Titan IV, with no catastrophic failures at all. Only Centaur failure was Titan IVB B-32 where the Centaur placed the Milstar 3 satellite in the wrong orbit due to incorrectly developed software which caused loss of roll control which then caused loss of yaw and pitch control. The loss of attitude control caused excessive firings of the Reaction Control System and subsequent hydrazine depletion. Erratic vehicle flight during the Centaur main engine burns caused the Centaur to achieve an orbit apogee and perigee much lower than desired

---------- Post added at 02:56 AM ---------- Previous post was at 02:55 AM ----------

Also, how is the bellows animation development coming along?
 

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Well, was just a random find looking for trajectory planning references. But I think regardless of the probabilities, knowing what failure was considered thinkable is pretty interesting should we ever return to launch failures.


Also, how is the bellows animation development coming along?

Must wait in my TODO collection, I'll focus on the DPS design tasks first.

Am I the only one thinking that we need a better requirement management?
 
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