Quick tanks update...
John Added a 4" section in the tank mold and blew another bottle....The test was a success.
This adds 30% more volume and no more liner weight!
Based on best guess....this pushes the 1000PSI MR to close to 22 and 500 PSI close to 28.
We will have real fully finished tank numbers shortly.
This adds 30% more volume and no more liner weight!
Based on best guess....this pushes the 1000PSI MR to close to 22 and 500 PSI close to 28.
We will have real fully finished tank numbers shortly.
posted by Paul Breed at 7:47 PM
7 Comments:
If I may ask, what is the plan for tank fittings, and will it have top and bottom openings, or just one?
Presently just one fitting, o-ring seal inside the neck and retained with bolts through
both the composite overwrap and the bottle neck above the seal.
This seal held in the same bottle with no reinforcement to 125PSI
http://unreasonablerocket.blogspot.com/2010/12/pet-third-stage-cots-tank.html
After the failure the seal and holes in the neck had zero sign of stress.
Based on PET Ultimate tensile strength ~ 8Ksi we get to 800 PSI or so at the neck with ZERO over wrap.
I've thought about what it might take to put a second fitting in the bottle, basically change the mold to allow a second fitting knob to appear and blow into that hole, then cut off the end and polish the inside to work with an oring fitting.
Is the PET-Material also suitable for a cryogenic fluid, like LOX?
How high is the ultimate tensile strength of PET that you use? When you stretch PET you will increase sigma_u (like in the re-blown-section of the Bottle).
Greets from Bavaria.
Paul,
Have you considered using carbon braid? Ideal braid angle so hoop = 2x axial stress is 54.7 degrees. Or perhaps try using it only for hoop reinforcement.
http://www.braider.com/Products/Braided-Carbon-Biaxial-Sleevings.aspx
Dan S.
Pretty effective data, thanks so much for your article.
This blog is really helpful to me, Lots of idea I got from this site.
Post a Comment
<< Home