[vkrastev]

Hi all,

my issue is quite straightforward: I need to map a data set (velocity field), which is contained in a csv file, onto an OpenFOAM mesh for flow initialization. The data set is 3D and ordered in columns. I have 3 columns representing the x,y,z coordinates of the nodes where velocities are stored, plus 3 columns representing the x,y,z velocity components. I know how to export data from OF to csv files (through Paraview), but I don't know how to do the opposite. Note that in my case the coordinates contained in the csv file are perfectly conformal to the coordinates of the cell centres in the target mesh. The latter is a simple 64^3 cubic mesh with equally spaced hexahedrons.

Thank you in advance for your help

V.

[akidess]

I don't think there's a built-in way. It's fairly straight forward to write your own tool though that reads your input file, finds the corresponding cells (using the convieniently named mesh.findCell function) and sets the value. Your mesh is so small you probably don't even need to worry about parallelization.

[vkrastev]

Originally Posted by akidess

I don't think there's a built-in way.

I was suspecting this, what surprises me is that I've found a relatively low amount of people asking about this (missing) feature around the web...

Originally Posted by akidess

(using the convieniently named mesh.findCell function) and sets the value.

Can you share some coding example or piece of existing code where this function is applied?

Thanks

V.

[akidess]

I wrote very similar code for my PhD, but it will take a while to dig it up again.

[vkrastev]

Originally Posted by akidess

I wrote very similar code for my PhD, but it will take a while to dig it up again.

Well, if you succeed in digging it up that would be great.

Thanks anyway for your responses.

V.

[akidess]

    for (long row=1; row<=csv_total_rows; row++)
    {
        for(long column=1; column<=csv_total_columns; column++)
        {
            long index = (row-1)*csv_total_columns+column-1;
            scalar xpos = csv_data[index].nodeposition[0];
            scalar ypos = csv_data[index].nodeposition[1];
            scalar zpos = csv_data[index].nodeposition[2];
            vector pos(xpos, ypos, zpos);
            label ofCellLabel = vsf().mesh().findCell(pos);
            vsf[ofCellLabel] = csv_data[index].value();
        }
    }

Where vsf is your volScalarField, and you read and parsed the CSV file by standard C++ methods somewhere else. Easy

[vkrastev]

Ok, thanks.

[kudetisiddhartha]

Originally Posted by akidess

    for (long row=1; row<=csv_total_rows; row++)
    {
        for(long column=1; column<=csv_total_columns; column++)
        {
            long index = (row-1)*csv_total_columns+column-1;
            scalar xpos = csv_data[index].nodeposition[0];
            scalar ypos = csv_data[index].nodeposition[1];
            scalar zpos = csv_data[index].nodeposition[2];
            vector pos(xpos, ypos, zpos);
            label ofCellLabel = vsf().mesh().findCell(pos);
            vsf[ofCellLabel] = csv_data[index].value();
        }
    }

Where vsf is your volScalarField, and you read and parsed the CSV file by standard C++ methods somewhere else. Easy

Hallo,

I am very new to OpenFoam and c++ coding. I have a similar case like this. Can you please help me on how and where should i implement this in my source code?
Regards