Skip to content

Latest commit

 

History

History
109 lines (74 loc) · 5.32 KB

INSTALL.md

File metadata and controls

109 lines (74 loc) · 5.32 KB
Raw

Documentation

Installing Channelflow

Channelflow is hosted on GitHub, using the distributed version control system git. To obtain a copy of the code clone the current repository running

git clone https://github.com/epfl-ecps/channelflow

Prerequisites

To compile Channelflow:

  • CMake (version 3.1 or higher)
  • C++11 supportive compiler (tested minimum compiler versions: GNU 4.8.1, Intel 16.0, Clang 6.0)
  • FFTW (version 3 or higher)
  • Eigen3 (version 3 or higher)

To enable parallelization, to use the NetCDF format (easy visualization with Paraview, VisIt ...) and to enable the parallel I/O:

  • MPI
  • NetCDF (parallel version 4 or higher)
  • HDF5(cxx) (format available for backwards compatibility)

To use Channelflow functions from the Python wrapper:

  • boost-python

Compilation

A Makefile to compile and install Channelflow can be generated using the provided CMake build scripts. CMake allows two build types: "release" and "debug". The build type decides on compiler options and whether assertions are compiled. Use "release" for optimal performance (e.g. for production runs) and "debug" for optimal diagnostics (e.g. for code development). Out of source builds are recommended.

mkdir build
cd build
cmake PATH_TO_SOURCE -DCMAKE_BUILD_TYPE=debug (/release) (configuration options)
make -j
make install

Channelflow supports, beneath other standard cmake flags, the following options

Option Values Default Description
-DCMAKE_INSTALL_PREFIX path usr/local Installation path for make install
-DUSE_MPI ON/OFF ON Enable MPI
-DWITH_SHARED ON/OFF ON build shared channelflow and nsolver libraries
-DWITH_STATIC ON/OFF OFF build static libraries (also enables linking to static libraries)
-DWITH_PYTHON ON/OFF OFF build a python wrapper for flowfields, disabled by default because it requires boost-python
-DWITH_HDF5CXX ON/OFF OFF enable legacy .h5 file format (using HDF5 C++)

A complete installation, with all features enabled, might look like this:

cmake PATH_TO_SOURCE -DCMAKE_BUILD_TYPE=release -DCMAKE_INSTALL_PREFIX=$HOME/usr -DWITH_PYTHON=ON -DWITH_HDF5CXX=ON

Tests

The correct functionality of the Channelflow code is tested in two ways:

  • Unit tests are tests of individual classes or methods.
  • Integration tests are tests of applications with all underlying code.

Both test types are hooked to the make test command, where they run sequentially. If all tests pass successfully, the installation was successful. When make test hangs on executing a test, re-run the tests and see if the problem persists. For verbose output and debugging, run make test ARGS="-V"

Unit tests use the googletest framework, which comes bundled with channelflow in its version 1.8.0. To run only the unit tests, run tests/gtest/runUnitTest in the CMake build directory. Individual tests can be run by passing --gtest_filter=<foo> as an argument, where <foo> is a name or pattern of a specific unit test. One example would be tests/gtest/runUnitTest --gtest_filter=TimeStepTest.* to run all tests of the time stepping class. More on unit testing can be found in the googletest Documentation.

Integration tests are found in folder tests, and registered in tests/CMakeList.txt. They are compiled into standalone programs, which are individually listed in tests/CMakeList.txt from where they are called on make test. For debugging, each integration test can be run individually and with various command-line arguments.

Doxygen

A webpage based on Doxygen is generated by running make doc (if doxygen is installed). A directory named html is automatically generated in the build directory. To access the webpage, open the file html/index.html.

Running your first simulations

To run a DNS we first need to provide an initial velocity field. This can be done providing a specific file or creating a random flowfield using the utility randomfield in the tools folder.

Running the command line

randomfield -Nx 48 -Ny 81 -Nz 32 -Lx 3 -Lz 2 newfield.nc

a random flowfield with zero-divergence, Dirichlet boundary conditions and the specified resolution and geometry is created.

Time integration of this initial condition is performed by the program simulateflow in the programs folder. The specific system to be simulated is specified via the program's options.

The following example integrates for 200 advective time units a simple plane Couette system at the default Reynolds number 400 .

simulateflow -T 200 newfield.nc

The following example simulates a pressure driven (-dPds) Poiseuille flow (-Uwall 0) at the Reynolds number 1000 using a 1st order forward-backward euler scheme as initial time stepping algorithm (-is).

simulateflow -R 1000 -Uwall 0 -dPds -0.002 -is SBDF1 newfield.nc