Heat Transfer Questions & Answers | |
|
|
What is given is not the heat generation per surface area but the power in W. Thus, the heat generation per unit volume $S$ is the power divided by the volume. I'll give you 0.5 point bonus boost for your question because it's not really a question but a misunderstanding of the problem statement.
|
|
|
|
You need to fix your question before I can answer it. Please typeset your mathematics better by making the parentheses as large as the terms within them are. Also, phrase your question better. I can not understand what you don't understand. Explain in more detail what you don't understand with additional information and example(s) if necessary.
|
|
|
|
If you're seeking the center temperature in a cylinder, sphere or plane wall, then there's no need to use the “temperature distributions” charts. Just use the chart “centerline temperature” or “midplane temperature”. I think I mentioned this in class, so I'll give only 1 point bonus boost for this question.
|
|
|
|
You should always compute $\alpha$ using more fundamental properties $k$, $c$, etc, and never use $\alpha$ directly from the tables. This is because in the tables some solids have a range of $c$, $k$, etc, and not specific values. The value you choose for $k$ and $c$ at one point in your solution must be the same as those that are used to calculate $\alpha$, or your solution will be inconsistent. I think I mentioned this in class already, so I'll give you just 0.5 point bonus boost.
|
|
|
|
You can still use the Heisler charts if $\textrm{Fo}<0.2$. But keep in mind there will be a more substantial error on the term determined. In this case, the error is on the parameter $(T_0-T_\infty)/(T_i-T_\infty)$. Thus, if your Fourier number is much less than 0.2, and you have no choice but to use the Heisler chart to solve the problem, you need to make a statement in your solution that there may be significant error on a certain term (don't just say there is error, specify on which term the error is high). I liked your question but it was sloppily typed with no uppercases at the beginning of sentences and some wrong uppercases in the middle of sentences. I'll give you 1 point bonus boost for it.
|
|
|
|
||||||||
$\pi$ |