Hydrostatic pressure using simpleFoam
 

Hi,
I created the same thread on the main CFD forum but it was displaced (but I don't know where...), so I ask my question again on the OpenFoam forum (I hope I'm now at the good place :o)
So, I'm going to try to make my question short : I have a vertical pipe with fluid inside (laminar flow, no tubulence); how can I add gravity to simpleFoam and which boundary conditions (more especially for the top and the bottom, since I can use cyclic bc or wall bc for front, back, left and right) can I use for the different walls (so as to have an hydrostatic pressure distribution and 0 velocity after use of simpleFoam as flow solver) ?
I have an additional question : could someone tell me what does " 'calculated' bc type" mean ? Could you give me a simple example of use (for p or U patches) ? I hardly found information about this topic in this forum and the information I found were not clear for a beginner like me.
I want information about "'calculated' bc type" because I would like to know if It is a way not to have to specify both p, U and other parameters on each patch (once a patch is declared on blockMeshdict) : mathematically, specifying all the parameters of a study for all patches could be too restrictive (and so could distort the solution)... Moreover the simple example of the Poiseuille flow shows that we don't need to impose both velocity and pressure at inlet and outlet : in the real life experiment we just impose a pressure difference between the inlet and the outlet... I hope you'll be able to help me because this time, I believe I'm on the good forum (tell me if it is not the case :p).
Thanks,

Hi,
I managed to add gravity by creating my own simpleFoam solver using wmake. However, there is no difference between the results of simpleFoam (I'm using Cygwin on Windows) and those of my_simpleFoam (post-processing forces files are exactly the same). In attachment, you'll find the files I modified (that are located in my_simpleFoam). Could you tell me if what I did on these files is correct (in order to add gravity or an other body force) ? Since I have a kinematic pressure what could I do about pho (because this parameter is needed in peqn and ueqn so as to have the good units) in createfields.H ?
There were similar threads about adding gravity in simpleFoam but It seems that the versions they used were older (since p.eqn and u.eqn they used are not the same as mine).
Just for information : I use OpenFoam 2.3.X with Cygwin64.
Thanks. :confused:

have you got the answer to your question? Could you please share that ?