[ulugbey]

Hi,

I have a divergent duct in Openfoam. I simulate it with 20 processors. I need to increase inlet pressure successively during the simulation. For example after 0,5ms. I will increase the inlet pressure. How should I realise it? Should I go to the 0.005 folder and change the pressure inside this folder and then decompose the domain again. Or should I go to the each processor files and change the pressure inside each processor files? For the second option I think I would not need to decompose the domain again .

Your help will be appreciated!

Thanks

[clapointe]

There are time-varying boundary conditions that will change it for you, so the manual editing isn't necessary! The first that comes to mind is uniformFixedValue, using a table to specify how you want the value to change with time. So it'd look something like :

        type            uniformFixedValue;
        uniformValue    table
        (
            (0 100000)
            (0.005 200000) //replace with desired value(s)
        );
        value           $internalField;

Note that I've not tested this, specifically, but I've used the bc like this in the past and the functionality is there (there are likely also many other options -- this is just the first I thought of).

Caelan

[ulugbey]

Thanks a lot for the reply
I use at the inlet total pressure boundary condition. So I changed the boundary condition at the inlet as follows:

    inlet
    {
        type           uniformTotalPressure;
        rho             rho;
        psi             none;
        gamma        1.4;
        p0              table 
        (
                        (0       130000)
                        (0.0007  170000)
                        (0.0014  210000)
                        (0.0021  260000)
                        (0.0028  310000)
                        (0.0035  460000)
                        (0.0042  410000)
                        (0.0049  460000)
                        (0.0056  51000)
                        (0.0063  560000)
                        (0.0070  610000)
                        (0.0077  660000)
                        (0.0084  710000)
                        (0.0091  760000)
                        (0.0098  800000)
        );
;
    }

I get the following error :

wrong token type - expected Scalar, found on line 1652435 the word 'table'

Do you know how to deal with the table for the total pressure boundary condition?
Thanks in advance!

[clapointe]

That appears to work for the version of openfoam I referenced (e.g. example case), so I'd guess that it will depend on the version... I found the linked case with a quick search of the available tutorials, so it'd be worth doing the same for the version you're using.

Caelan

[ulugbey]

Hi,
Thanks. I use Openfoam 2.1.1, which is a very old version. I cant find any information about my question for this version

[clapointe]

A quick search of 2.1.x shows that (presumably) the same tutorial also uses a table in the bc : tutorial. So at a glance it looks like the same functionality is available -- it just expects a slightly different format.

Caelan