OpenFOAM post-processing cheat sheet (updated from time to time)

Introduction

This article summarizes how to use OpenFOAM's post processing utility postProcess. It is a utility that can output various information about meshes and physical quantities. It can be used both during and after the simulation, but this article summarizes it after the simulation.

Let the working directory of OpenFOAM be caseDir.

How to get the field of physical quantity at each time

Q (second invariant of velocity gradient tensor)

The calculation result of speed is required for execution.

caseDir$ postProcess -func Q

A file named Q is output in the time directory.

y+ Outputs the y + distribution on the wall patch. Execute with the postProcess utility as an option. In the case calculated by pimpleFoam

caseDir$ pimpleFoam -postProcess -func yPlus

A file named yPlus will be output in the time directory.

How to get time series data for a specific point

probe To execute it, you need to prepare the calculation result of the physical quantity you want to acquire and a dictionary file called probes in systems. The contents are

probes

/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  7
     \\/     M anipulation  |
-------------------------------------------------------------------------------
Description
    Writes out values of fields from cells nearest to specified locations.

\*---------------------------------------------------------------------------*/

#includeEtc "caseDicts/postProcessing/probes/probes.cfg"

fields (U);    //Enter the physical quantity you want to acquire in parentheses. In case of multiple, separate with a half-width space(U p ...) 
probeLocations
(
    (0.12 0.01 0.05)    //Coordinates of the point you want to get(x, y, z)
    (0.2 0 -0.5)
);

// ************************************************************************* //

Run

caseDir$ postProcess -func probes

A directory called postProcessing is created in caseDir, and time series data files are output in it.