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Retrieving Unsteady pressures rans equations

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Old   December 14, 2021, 11:26
Default Retrieving Unsteady pressures rans equations
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suresh
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Hi,

I am solving rans equations. I am able to get the pressures due to convective acceleration (u.d(u, n))., which leads to
0.5 *rho* u^2 upon spacial integration.
May I know how to get the unsteady pressure caused due to temporal acceleration. d(u, t) ??

Can some one help or share view?
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Old   December 14, 2021, 11:35
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Filippo Maria Denaro
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Quote:
Originally Posted by dskvsp View Post
Hi,

I am solving rans equations. I am able to get the pressures due to convective acceleration (u.d(u, n))., which leads to
0.5 *rho* u^2 upon spacial integration.
May I know how to get the unsteady pressure caused due to temporal acceleration. d(u, t) ??

Can some one help or share view?



1) if your solving the steady RANS equations there is no acceleration
2) if you are solving the URANS equations for compressible flows you have all that take into account the time-dependent pressure field.
3) if you are solving the unsteady URANS equations for incompressible flows you have to solve the Poisson equation for the pressure. But be aware that this is not the thermodynamic pressure.
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Old   December 14, 2021, 11:44
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suresh
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Originally Posted by FMDenaro View Post
1) if your solving the steady RANS equations there is no acceleration
2) if you are solving the URANS equations for compressible flows you have all that take into account the time-dependent pressure field.
3) if you are solving the unsteady URANS equations for incompressible flows you have to solve the Poisson equation for the pressure. But be aware that this is not the thermodynamic pressure.
Thanks Denaro, I will look into the urans equations and get back if I need help.
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bernouli, dynamic pressure, fluent, rans, unsteady pressure

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