Thermal Flow in Ceramic Material

[JOEYRDC]

Hello there fellow Eng-tips people,

I am doing design of Ceramic Housing that is exposed to Conduction (Oven Grill).
I need some help on how to compute the inner temperature and time before the inner surface reaches the same temperature as its outer wall

Reason is, I want to get the appropriate thickness of Ceramic that can maintain a good internal temperature in a given cooking time.

Thanks for the help!

 

[dvd]

An oven grill seems like it would be exposed to conduction, convection and radiation heat transfer modes. To not include all modes of heat transfer seems like an oversimplification. Also, what happens when the grill gets dirty? Does it exhibit the same thermal behavior? The mismatch of thermal expansion properties between ceramic and substrate may have some bearing on the problem also.

 

[JOEYRDC]

Yes, there are several modes but I will like to concentrate more on the Convection (sorry, not Conduction) at this time.
Will it be Fourier's law or another Heat Transfer equation?
I need it to be transient so time is essential to determine the temperature
Can you advise on how to get the right computation.

 

[prex]

This is a standard conduction inside-convection outside problem. You just use the correct material properties (conductivity, heat capacity). And if the geometry is that of a slab that can be assumed as being infinite, there must be an analytical (one dimensional) solution.

prex
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[chicopee]

Based on your initial assumption of convection on the surface of the ceramic insulation, first assume a T ambient and Hc to be constant values and then develop your heat transfer equations for unsteady state. Such equations are pretty well detailed in any fundamental heat transfer book.