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chicopee and cloa - I am heating a ceramic element that is a tube folded in half. It will be emitting on both sides, but one side will be close to a wall. I know the emissivity, the thermal conductivity, and the specific heat capacity. What additional information do I need to solve this...

Thanks chicopee. I'll look into it if I go back to school in the fall.

I'm not in school at this time. I'm not sure if I will be going back to school in the fall. I appreciate the help I have received so far. If I do enroll in classes in the fall, I will hunt down a thermodynamics professor and talk to them.

I found an solution to my problem in the book IRstuff posted (Example 2.8), however it involves an h-bar. At the beginning of the book is a calculation: h-bar = q/delta-T where: q = power/area Can I use: input power/area of element in the calculation of h-bar? So say I have 4000 W going...

I'm trying to calculate the temperature of the resistor. From there I will calculate the temperature of the air using section 3 of the book. Originally I was only trying to figure out how hot the resistor (heating element) got, but with this book, I realized I could do so much more. This has...

IRstuff: I looked at example 8.1, but it doesn't seem to apply for my situation. The calculations in that example seem to apply to fluids because they include ?, which is a function of dynamic viscosity of a fluid. I attempted what using theoretical values for delta-T, but the result was not...

I looked throughout the book and could not find an equation to suit my needs for calculating h-bar. I assumed that since the example gave a value for h-bar that this was some kind of constant based on the material. I did see at the beginning of the book examples for calculating h-bar, but they...

IRstuff - I looked at the Wikipedia article on convection and linked to the article on heat transfer coefficient, but I see nothing that would explain why the book you linked be to talks about the convection heat transfer coefficient of the resistor being some value, h-bar. For reference, I am...

Ceramicguy - I'm actually looking for the natural convection h-bar...any ideas? Thanks.

Ceramicguy - I found an emmissivity value, thanks. As for h-bar, how do you suggest I go about finding it? I can calculate a radiative h value (using temperature and emmissivity) that I will use in my final temperature calculation, but my equation seems to use a constant h-bar that is material...

I'm looking for a couple properties of MoSi2 ceramics. Does anyone know the heat transfer coefficient (h-bar) and the emmissivity (epsilon)? I'm trying to calculate how hot it will get when I apply power and I need these two values. Thanks in advance.

Thanks IRstuff. I'm going to go look at the book you posted.

MintJulep - watts doesn't equal temperature. I used quark's equation and got a result. I'm now wondering the limit of that equation...I can't heat infinitely.

IRstuff - I'm specifically talking about ceramics, not metals, but I know it increases for metals. I took one thermodynamics course seven years ago and have never used it since. I intend to look over the material you provided me, thank you.

quark: Found Cp for my material. How do I account for the fact that it will eventually stop heating up? I know I can't just apply power and have it heat to infinity.

IRstuff: For my model, I intended only to increase power (in watts) to see how the temperature increased. I know this is a very simple approach because as temperature increases, resistivity will decrease. I'm just trying to figure out how hot a material (with a given resistivity in Ohm-mm^2/m)...

MintJulep - I'm trying to calculate how hot the element will get. I have the information I provided in my first post. Thank you.

Nope, this is for an aerospace application I'm working to develop. I can't go into details because it's kind of sensitive right now. I could wait until August when I'm starting my next Master's degree and go find a professor to help me out, but this is easier and probably faster. I appreciate...

I'm looking for an equation that will give me the temperature of a heating element if I know the following: - resistivity (in ohms mm^2/m) - length (in meters) - cross-sectional area (in meters or mm) - power applied (in watts) Do I need anything else? I'm trying to build a computer model. Thanks.

PKerEng - I'm looking into doing a computer model of this, but of course that means I need data on the material (such as resistivity of the element). I'm looking at a circular element, similar to a stove (I think I stated that), but bigger. I know that the total heat will also depend on the...