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Numerical Diffusion in 1D Advection-diffusion solution

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Old   June 29, 2020, 16:20
Default Numerical Diffusion in 1D Advection-diffusion solution
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Nabeel Khan
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I used Finite Volume method and switched diffusion term off, but still I'm getting false diffusion in numerical solution for 1D case.

I understand it's occuring due to truncation error, I also tried using very small conntrol volume and very small time steps but still the error in solution is very high. I used 2nd order accurate discritization as suggested by Patanker in Numrical Heat Transfer and Fluid Flow

Please guide me how to reduce the error.

Please look at the video of simulation: https://drive.google.com/file/d/1nrl...ew?usp=sharing
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Old   June 29, 2020, 16:44
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Filippo Maria Denaro
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Quote:
Originally Posted by nabeelk04 View Post
I used Finite Volume method and switched diffusion term off, but still I'm getting false diffusion in numerical solution for 1D case.

I understand it's occuring due to truncation error, I also tried using very small conntrol volume and very small time steps but still the error in solution is very high. I used 2nd order accurate discritization as suggested by Patanker in Numrical Heat Transfer and Fluid Flow

Please guide me how to reduce the error.

Please look at the video of simulation: https://drive.google.com/file/d/1nrl...ew?usp=sharing



Could you write exactly your scheme? The plot shows a monotone and diffusive behavior typical of a first order accurate scheme
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