- #1

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I need a fem code either in matlab or fortran to refer to as I am stuck at some places. Please help.

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- Thread starter nellierd
- Start date

- #1

- 11

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I need a fem code either in matlab or fortran to refer to as I am stuck at some places. Please help.

- #2

minger

Science Advisor

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Perhaps you can shed some light on where you're stuck. No one is going to do your work fro you.

- #3

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The fact that gets me, is that these posters actually think this forum is intended for this type of help.

LOL

Matt

- #4

minger

Science Advisor

- 1,495

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Code:

`Hello World!`

Hell, I'd zip it up and make sure it was always hosted.

- #5

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When you solve a transient problem of the format.

If you have M du/dt+K u=F, we can break it into Mv(1)+K(u1)-F(1)=0 at t=t1 and

Mv(0)+K(u0)-F(0)=0. Using the trapezoidal rule, it asks to guess the V vector at t1 even though its a linear problem. I am very confused with the approach.

- #6

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Why did you ask for a FEM (finite element code) when you are told to use the trapezoidal rule?

The trapezoidal rule is nothing more than a numerical integration algorithm. Albeit a very robust one.

If your going to post a silly question then get ready for the criticism. When you post questions here act as if you are asking your supervisor the question. Then ask yourself the following questions.

1. Have I specified enough information so that someone can actually help me?

2. Is there any additional information that I can post that will help the person(s) trying to help me?

3. Is the spelling/grammer correct to the best of my knowledge?

4. Have I searched the forum for a similar question?

5. Is there a graph/picture that I can attach to help with the visualization of the problem?

Remember, we are not in the class with you, so make it easy for us to help you.

Thanks

Matt

The trapezoidal rule is nothing more than a numerical integration algorithm. Albeit a very robust one.

Hey, enough of criticism.

If your going to post a silly question then get ready for the criticism. When you post questions here act as if you are asking your supervisor the question. Then ask yourself the following questions.

1. Have I specified enough information so that someone can actually help me?

2. Is there any additional information that I can post that will help the person(s) trying to help me?

3. Is the spelling/grammer correct to the best of my knowledge?

4. Have I searched the forum for a similar question?

5. Is there a graph/picture that I can attach to help with the visualization of the problem?

Remember, we are not in the class with you, so make it easy for us to help you.

Thanks

Matt

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- #7

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- #8

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Ugh.

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@Brian, y was your response like this? Was my question so annoying?Ugh.

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- #11

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Let me rephrase the question in terms of temperature.

When we solve MV(0)+KU(0)-F(0)=0 for V(0), where V(0) is the dT/dt at time t=0 and U(0) being the temperature. Do we impose the secondary boundary conditions like flux in our F(0) vector and also the given temperatures in our U vector. I am getting confused as if the primary value i.e U is known at certain nodes, V should be zero. About the secondary boundary conditions(du/dx or du/dy)...do I impose them too? If I am calculating V for time t=0 using that equation, my question is if I am calculating V for all nodes? or the interior nodes? or the nodes where only the primary value is given?

Hopefully, this might be clearer.

Also if on two boundaries ,adjacent ones, fluxes are prescribed on both of them, which one takes precedence? for example , one boundary has flux given 10 and another 100. The node common to both these boundaries will take what value of flux?

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