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Different Implementation in solving pEqn

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Old   October 23, 2009, 12:46
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  #21
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Nishant
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Hi Matvej

I have advanced a bit ahead with my last problem. The previous error is sorted out. it was because of the difference in meshing and boundary condition.

However I am still wondering with the question of different implementation of p-equation. I mean..
when we use phi in pEqn (), we use
phi += pEqn.flux();
And when we use phid etc then we use
phi = pEqn.flux();

I am still wondering why?? Any hint please?

regards,
Nishant
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Old   November 5, 2009, 15:16
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Matvej Kraposhin
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Hi, I'm very sorry for late reply (too much work).
Anyway, if this answer is still needed:

when we update velocity (phi = velocity*density*area) in diffusion pressure equation, we mean that dU ~ const * grad(dp). If we are using convection-diffusion equation for pressure: ddt(psi,p) + div(phi_d, p) - div(rho/A*grad(p)), we are solving for mass flux, which satisfies continuity equation.

Another words:
- diffusion equation - correction to mass fluxes (to satisfy continuity) - phi+=pEqn.flux()
- convection-diffusion - mass fluxes, which continuity - phi=pEqn.flux()

I hope, this helps you. I'm really sorry for late post
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Old   June 25, 2013, 08:40
Default please would you guide me in running a new application on OpenFOAM
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Anil Kunwar
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i am new to OpenFOAM.
i was going through the "OpenFOAM Programming Tutorial" written by Tommaso Lucchini. i modified icoFoam to icoScalarTransportFoam and cavity to cavityScalarTransport in accordance to the directions of the notes.
now i cannot set up the case cavityScalarTransport and cannot run it. would you please guide me with the commands for running this new application.thanking you in advance.

Last edited by Annier; July 23, 2013 at 02:03.
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