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 April 23, 2016, 05:37 I am new to Cfd. Please help to develop a MATLAB for this problem #1 New Member   Priyanka Join Date: Oct 2015 Posts: 14 Rep Power: 3 Sponsored Links A thin plate is initially at a uniform temperature of 200C. At a certain time t = 0 the temperature of the east side of the plate is suddenly reduced to 0C. The other surface is insulated. Use the explicit finite volume method in conjunction with a suitable time step size to calculate the transient temperature distribution of the slab and compare it with the analytical solution at time (i) t = 40 s, (ii) t = 80 s and (iii) t = 120 s. Comparison should be shown in a graphical plot as well as in a tabular form showing the percentage error with the analytical solution. Recalculate the numerical solution using a time step size equal to the limit given by the stability criteria (possibly 8 second or higher) for t = 40 s and compare the results with the analytical solution. Solve the problem using the both Crank-Nicholson scheme and fully implicit scheme and compare the results with analytical results at (i) t = 40 s, (ii) t = 80 s and (iii) t = 120 s. With a time step of 8 s, compare the results of all these three schemes (explicit, implicit and Crank-Nicholson) at time t = 40 s. The data are: plate thickness L = 2 cm, thermal conductivity k = 10 W/m/K and C = 10x106 J/m3 /K.

 April 23, 2016, 09:28 #2 Senior Member   Michael Prinkey Join Date: Mar 2009 Location: Pittsburgh PA Posts: 334 Rep Power: 16 http://lmgtfy.com/?q=matlab+crank+nicholson Is there a policy here about cutting and pasting homework problems? I honestly don't mind helping students with particular problems or questions, but these type of posts really annoy me. I am never going to be inclined to help someone who has clearly made zero initial effort. I suspect that most knowledgeable people here feel similarly. So, are these reportable? If not, should they be? tas38, FMDenaro, davidwilcox and 2 others like this.

April 23, 2016, 11:42
#3
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Filippo Maria Denaro
Join Date: Jul 2010
Posts: 3,416
Rep Power: 39
Quote:
 Originally Posted by mprinkey http://lmgtfy.com/?q=matlab+crank+nicholson Is there a policy here about cutting and pasting homework problems? I honestly don't mind helping students with particular problems or questions, but these type of posts really annoy me. I am never going to be inclined to help someone who has clearly made zero initial effort. I suspect that most knowledgeable people here feel similarly. So, are these reportable? If not, should they be?

I agree.... perhaps someone could argue that a sub-section for homework requests could be an idea, too...

April 25, 2016, 07:08
#4
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Arjun
Join Date: Mar 2009
Location: Nurenberg, Germany
Posts: 702
Rep Power: 19
Quote:
 Originally Posted by mprinkey http://lmgtfy.com/?q=matlab+crank+nicholson Is there a policy here about cutting and pasting homework problems? I honestly don't mind helping students with particular problems or questions, but these type of posts really annoy me. I am never going to be inclined to help someone who has clearly made zero initial effort. I suspect that most knowledgeable people here feel similarly. So, are these reportable? If not, should they be?

Actually this is why i completely stopped visiting cfd online. I was contacted by many people about their masters or phds work and often found myself doing their thesis work. Like meshing and running simulations etc.

Asking on forum is some what forgivable because anyone can answer but still many times it shows that person did not do proper search or put proper effort.

 April 25, 2016, 07:14 #5 New Member   Priyanka Join Date: Oct 2015 Posts: 14 Rep Power: 3 I am an undergraduate. How can you say that i put zero effect. I tried it.I also tried googe if it could help me out. I know that i am at zero level but everything starts from there. Help me if you can. If you are too busy then you can ignore the post. There is no compulsion that you have to answer every question posted. Thank you.

April 25, 2016, 07:42
#6
Senior Member

Michael Prinkey
Join Date: Mar 2009
Location: Pittsburgh PA
Posts: 334
Rep Power: 16
Quote:
 Originally Posted by Priyanka Konakandla I am an undergraduate. How can you say that i put zero effect. I tried it.I also tried googe if it could help me out. I know that i am at zero level but everything starts from there. Help me if you can. If you are too busy then you can ignore the post. There is no compulsion that you have to answer every question posted. Thank you.
Quote:
 Originally Posted by Priyanka Konakandla I am an undergraduate. How can you say that i put zero effect. I tried it.I also tried googe if it could help me out. I know that i am at zero level but everything starts from there. Help me if you can. If you are too busy then you can ignore the post. There is no compulsion that you have to answer every question posted. Thank you. Your post is offensive
You cut and pasted the problem description from your instructor. You asked the forum to do your homework for you. This is not how you learn. If you had asked, "What is the difference between fully implicit and Crank Nicholson?" or "I've implemented this matlab code but it doesn't work...what am I doing wrong?" I and others would likely have helped you.

But you didn't. You took TWO problems exactly as issued by your instructor and posted them on a forum filled with highly competent CFD researchers and practitioners and asked them to think for you. If I were your instructor and saw your post, I would give you zero credit for whatever assignment you turned in.

April 25, 2016, 07:55
#7
Senior Member

Filippo Maria Denaro
Join Date: Jul 2010
Posts: 3,416
Rep Power: 39
Quote:
 Originally Posted by Priyanka Konakandla A thin plate is initially at a uniform temperature of 200C. At a certain time t = 0 the temperature of the east side of the plate is suddenly reduced to 0C. The other surface is insulated. Use the explicit finite volume method in conjunction with a suitable time step size to calculate the transient temperature distribution of the slab and compare it with the analytical solution at time (i) t = 40 s, (ii) t = 80 s and (iii) t = 120 s. Comparison should be shown in a graphical plot as well as in a tabular form showing the percentage error with the analytical solution. Recalculate the numerical solution using a time step size equal to the limit given by the stability criteria (possibly 8 second or higher) for t = 40 s and compare the results with the analytical solution. Solve the problem using the both Crank-Nicholson scheme and fully implicit scheme and compare the results with analytical results at (i) t = 40 s, (ii) t = 80 s and (iii) t = 120 s. With a time step of 8 s, compare the results of all these three schemes (explicit, implicit and Crank-Nicholson) at time t = 40 s. The data are: plate thickness L = 2 cm, thermal conductivity k = 10 W/m/K and C = 10x106 J/m3 /K.

this is just a homework ....

 April 25, 2016, 09:02 #8 Member   Join Date: Jul 2013 Posts: 49 Rep Power: 6 I found this presentation by googling your statement. Slide 13 is an exact match. What you ask is basically plagiarism. mprinkey, tas38 and FMDenaro like this.

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