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John Abbott
Mathematics in Industry Workshop 06/16/2008
MTE-AMA
Elongating Bubble in an Accelerating Extensional Flow
2June 2008Mathematical Problems in Industry June 2008
Outline
• Introduction to Corning!• Brief Problem Statement• Background, Introduction, and Context
– Pictures
– References & Previous work
• Restatement of Problem• Extensions, further work which might be possible
3June 2008Mathematical Problems in Industry June 2008
Corning Incorporated
• R&D labs celebrating 100th year anniversary• Corporate member of IMA at Univ. of Minnesota• Emphasis on innovation and new products
– Light bulb: worked with Edison, all incandescent light bulbs in the world are made by the high speed ‘ribbon machine’ developed by Corning
– Glass for Cathode Ray TVs (CRTs); color TVs– Silicones – spun off to Dow-Corning (private company)– Fiber glass insulation – spun off to Owens-Corning Fiberglas– Optical Fiber – low cost, low attenuation optical fiber for
telecommunications– Precision glass for LCD flat panel displays– Extruded Ceramics for catalytic converter substrates– Specialty glass & ceramics (mirror blank for Hubble telescope)
4June 2008Mathematical Problems in Industry June 2008
Environmental Products
Corning makes ceramic ‘substrates’ catalytic converters for cars
The substrate is made by extruding wet ceramic through a die with hundreds of holes – the holes need to be uniform.
In drilling the holes the drills used to wear out..
5June 2008Mathematical Problems in Industry June 2008
Display – Large Glass Sheets for LCD displays
Corning invented a process for making sheet glass where the glass flows over two sides of a ‘weir’, so that the final sheet has two pristine surfaces.
Gen 8 2160x2460mm
Gen10 3000x3000m
0.7mm thick
6June 2008Mathematical Problems in Industry June 2008
Optical Fibers
One of Corning’s big businesses
is optical fiber – essential to the internet.
The combustion synthesis process used to make pure SiO2 was developed by Franklin Hyde at the Corning R&D labs, the same fellow who invented silicones. The same process is used to make windows for the space shuttle and the glass for the Hubble space telescope.
GeO2 &SiO2 – optical fibers
TiO2 & SiO2 – low thermal expansion
8June 2008Mathematical Problems in Industry June 2008
Outline
• Introduction to Corning!• Brief Problem Statement• Background, Introduction, and Context
– Pictures
– References & Previous work
• Restatement of Problem• Extensions, further work which might be possible
9June 2008Mathematical Problems in Industry June 2008
Problem Statement
How is a single spherical bubble or ‘seed’ stretched as it moves down the tapering root during a high speed optical fiber draw process?
The leading tip of the bubble sees an exponentially increasing velocity (and extensional rate). How (if at all) does the shape differ from the distortion in either simple shear flow or simple extensional flow.
10June 2008Mathematical Problems in Industry June 2008
Outline
• Introduction to Corning!• Brief Problem Statement• Background, Introduction, and Context
– Pictures
– References & Previous work
• Restatement of Problem• Extensions, further work which might be possible
11June 2008Mathematical Problems in Industry June 2008
“Blisters” in volcanic magma
Rust, Manga, Cashman 2003
12June 2008Mathematical Problems in Industry June 2008
Experimental measurement of bubble shapes
Rust, Manga 2002
An optical fiber airline has a large aspect ratio l/a
13June 2008Mathematical Problems in Industry June 2008
Previous Analysis (Hinch & Acrivos papers)
[11] Hinch, E.J., and Acrivos, A., “Long slender drops in a simple shear flow”, Journal of Fluid Mechanics Vol. 98 Issue 2 (1980) pp. 305-328.
Some differences between ‘simple shear flow’ and ‘simple extensional flow’
14June 2008Mathematical Problems in Industry June 2008
Previous Analysis (Howell & Siegel papers)[15] Howell, P.D., and Siegel, M., “The evolution of a slender non-axisymmetric drop in an
extensional flow”, Journal of Fluid Mechanics Vol. 521 (2004) pp. 155-180..
Both Howell-Siegel and Hinch-Acrivos predict the pointed ends to the elongating bubbles which is seen in practice.
15June 2008Mathematical Problems in Industry June 2008
Generic Draw Model –use Huang/Miura/Wylie where possible.
[9] Huang, H., Miura, R.M., and Wylie, J.J., “Optical Fiber Drawing and Dopant Transport”, submitted to SIAM J. Applied Math 2008
www.math.yorku.ca/Who/Faculty/hhuang/preprints/DopantFinal.pdf
Where log R vs. z is convex, heat is going into blank.
Where log R vs. z is concave, heat is coming out.
Because of cylindrical geometry 2D plot does not show cross-sectional area.
dT/dz=0 determines ‘inflection’
log R
16June 2008Mathematical Problems in Industry June 2008
Velocity U(z) and extension rate dU/dz
z
(du/dz) log u(z)
z
We can approximate u(z) by something convenient: exponential heating, exponential cooling.
17June 2008Mathematical Problems in Industry June 2008
Input to problem
Need assumed V(z) and dV/dz.
Blank shape D(z), velocity V(z), and temperature T(z) all need to be consistent.
JSA to provide base model.
18June 2008Mathematical Problems in Industry June 2008
Outline
• Introduction to Corning!• Brief Problem Statement• Background, Introduction, and Context
– Pictures
– References & Previous work
• Restatement of Problem• Extensions, further work which might be possible
19June 2008Mathematical Problems in Industry June 2008
Problem Statement
How is a single spherical bubble or ‘seed’ stretched as it moves down the tapering root during a high speed optical fiber draw process?
20June 2008Mathematical Problems in Industry June 2008
Outline
• Introduction to Corning!• Brief Problem Statement• Background, Introduction, and Context
– Pictures
– References & Previous work
• Restatement of Problem• Extensions, further work which might be possible