# Transient Solution Problem

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October 20, 2016, 12:47
Transient Solution Problem
#1
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Join Date: Jun 2016
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The model which I work on reach steady state conditions after approxiamately 10800s. I added picture.

I analyzed as statedy state solution. But result is not same transient solution due to the time scale reach steady state is very large.

I will try to analyze as transient solution.

time step < (smallest mesh size/velocity)

time step < 0.0006s

For 10800s

Time step size 0.0005
Number of time step 21600000

This take long time. How can I solve this problem. Is there sımple way for this.

Best Regards
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 October 21, 2016, 02:00 #2 New Member   babanpreet singh Join Date: Mar 2016 Posts: 7 Rep Power: 8 Try to do steady state with density and chose implicit approach

 October 21, 2016, 05:35 #3 Member   Join Date: Jun 2016 Posts: 31 Rep Power: 8 Thank you for your answer. Could you please explain a little more.

October 21, 2016, 06:56
#4
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in implicit method, the solution progresses stably, hence possible to get the desired solution. Whatever may be the solution method, it is important to analyze with reference to the physics of the problem.

If you can send a brief writeup about you case, we can provide you the specific solution for your case. you can send text messages on:
http://workshopwale.com/ or can email at: adarsh@workshopwale.com

Quote:
 Originally Posted by typhoon1010 I would like to ask question about transient solution. The model which I work on reach steady state conditions after approxiamately 10800s. I added picture. I analyzed as statedy state solution. But result is not same transient solution due to the time scale reach steady state is very large. I will try to analyze as transient solution. time step < (smallest mesh size/velocity) time step < 0.0006s For 10800s Time step size 0.0005 Number of time step 21600000 This take long time. How can I solve this problem. Is there sımple way for this. Can you advise me. Thank you in advance Best Regards

October 22, 2016, 05:04
#5
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Quote:
 Originally Posted by Workshop Technologies in implicit method, the solution progresses stably, hence possible to get the desired solution. Whatever may be the solution method, it is important to analyze with reference to the physics of the problem. If you can send a brief writeup about you case, we can provide you the specific solution for your case. you can send text messages on: http://workshopwale.com/ or can email at: adarsh@workshopwale.com

Best Regards.

 October 22, 2016, 07:33 #6 New Member   babanpreet singh Join Date: Mar 2016 Posts: 7 Rep Power: 8 Actually the thing is in implicit the number of equations to be solved is same as tge number of variable hence a constructive approach is made to all the equations but in explicit each variable have different equation easy to solve but explocit depends on time where as implicit is time independent

October 22, 2016, 11:16
#7
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Quote:
 Originally Posted by babanjaria Actually the thing is in implicit the number of equations to be solved is same as tge number of variable hence a constructive approach is made to all the equations but in explicit each variable have different equation easy to solve but explocit depends on time where as implicit is time independent