meaning of HbyA
Hi all,
I am not clear about the variable HbyA Code:
volVectorField HbyA("HbyA", U); In the 1.6ext version I found the same declaration: Code:
U = rUA*UEqn().h(); Thanks in advance Tobi 
I made slides some times ago to explain the PISO loops in OpenFOAM : http://fr.scribd.com/doc/143414962/P...oninOpenFOAM
They are in French but understandable. It uses old OpenFOAM version, that means without the HbyA notation. 



thx
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Dear Guys,
I'm using the 3step rungekutta scheme to solve Navier Stokes equation. There are some differences in the equations must be solved, but the main equations are same.you can see the equations in the attachment(those equations are put in a for loop, from k=1 to k=3) Also, below you can see my summarized code to solve that, but i don't know how to use coefficients(same as piso loop of icoFoam) ! I would appreciate any idea on how to change my code to something like the piso loop of icoFoam : Code:
while (runTime.loop()) 
Thanks guys for sharing this information!!
I am just going through the implementation of PISO/ PIMPLE in interFoam solver. I could understand and link most part of what is discussed here but confused at parts. Hope you can help me out!! Starting with UEqn.H: fvVectorMatrix UEqn ( fvm::ddt(rho, U) + fvm::div(rhoPhi, U) + turbulence>divDevRhoReff(rho, U) == fvOptions(rho, U) ); Over here we already have a solution for velocity without influence of pressure.{solving NSE excluding variables of pressure and body forces that dont have an explicit U term}. We extract the diagonal{UEqn.A()} and off diagonal portions {UEqn.H()}. Now passing to pEqn.H: We find and link velocity to flux over cell faces.(U > phi) Additionally due to surface tension force induced flux, we add flux to the above calculated flux. {Even here pressure isnt included till now}. Now the pressure corection is directly applied as follows: fvm::laplacian(rAUf, p_rgh) == fvc::div(phiHbyA) /*we are finding for p_rgh*/ From this further correction to flux and U from the found out pressure is calculated to get the conservative velocity. My question, 1. In all explanations I have had browsed through, they explicitly mention usage of pressure twice. One as an approximate and one found as a real value. But from interFoam solver I see only once the usage of pressure and it is the corrected pressure that we are solving for. {above equation, laplacian pressure} 2. What are nOuterCorrectors, nCorrectors variablels? I see their default definitions but where are we specifying the loop? I guess it has something to do with pimple.correct() loop but how are the variables being used? Thanks and interested to hear your views, Saideep 
For nouter and ncorr See my blog

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