Time dependance of temperature rise

AI Thread Summary
The discussion focuses on determining the temperature experienced by an optical fiber when subjected to an oven at 600°C. The user seeks a time-dependent equation to calculate the temperature at the center of an 80-micron diameter silica fiber, utilizing known thermal conductivity and constants. References to Heat Transmission by McAdams and Transport Phenomena by Bird, Stewart, and Lightfoot are made for guidance on heat transfer coefficients. The user emphasizes the need for first-order approximations rather than complex simulations. Assistance in identifying a relevant equation is requested to solve the problem effectively.
gilzers
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I feel very dumb that I cannot figure this one out despite a PhD in fiber optics, so looking for some bigger brains to help...

I'm passing an oven over an optical fiber and I'm trying to figure out what temperature the fiber will see in the center. I know the ambient temperature of the oven 600C, the size of the fiber which is 80 microns diameter and the material silica. So I can pull up the thermal conductivity and various other constants. I also know the speed and length of the oven. First order approximations are fine, I don't need to simulate the oven shape.

What I can't figure out is a time dependant equation that is relevant. Can anyone guide me to a relevant equation?
 
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See Heat Transmission by McAdams. He provides graphs of temperature profiles in cylinders heated from the outside by a heat transfer coefficient. But, you need to have an estimate of a reasonable value for the air-side heat transfer coefficient. Typical values are given in Transport Phenomena by Bird, Stewart, and Lightfoot.

Chet
 
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