ThermalMultiphaseOpenLB

This is an extension for OpenLB which allows for thermal single-component phase change multiphase flow

This extension was created by Julius Weinmiller as part of his master thesis. The final thesis will be uploaded shortly to TUDelft repository, and once avaliable will be linked here.

Features

With this extension, it is possible to simulate phase change using OpenLB of liquids at high density ratios.

An example usecase is flow boiling in microchannHelmholtz Institute Ulmels.

Code extensions

The extension includes:

• A new forcing algorithm for pseudopotential method
  • stable simulations high density ratios
  • thermodynamic consistent densities
• Multiphase thermal coupling DDF
  • Incorporation of latent heat via the equation of state
• Semi-hybrid thermal solver
  • Solves thermal equation with explicit euler
  • Helps with setting thermal diffusivity

Limitations

The original extension was created for OpenLB v1.3-1.

It is currently not working in combination with OpenLB v 1.4, but it is being worked on to make sure it functions as well

Quick Installation

1. Drop the phaseChangeExtension folder into the OpenLB base folder
2. In the global.mk file:

• add the line phaseChangeExtension/phaseChangeSource \ to the SUBDIRS and INCLUDEDIRS
• add -lgsl -lgslcblas to the LIBS after the -lz

3. One small change needs to be made in the file src/dynamics/dynamics.h

• Navigate to the class BounceBack (line 651)
• Change private to protected (line 701)

4. Compile and run the examples to make sure everything works

• Do not forget to change BUILDTYPE to generic in config.mk

Cleaner Installation

It is possible to organize the folders better, but it may break some references.

1. Place the source folder into the src/external/ folder

• Add the location of the source folder to global.mk

2. Place the python folder into the src/external/ folder

• The python files (Used only to generate plots) in the example program need to be given the proper reference to the eos.py file

3. Place the phaseChangeExamples into the OpenLB's examples folder

• If the examples do not compile, make sure that the ROOT in the definitions.mk is correct.
• Optional: add the examples to the EXAMPLEDIRS in the global.mk

4. Any other steps in the quick installation also need to be performed

• Reminder to add: -lgsl -lgslcblas
• Reminder to edit BounceBack

Core papers used

Q. Li, K. H. Luo, and X. J. Li. Forcing scheme in pseudopotential lattice Boltzmann model for multiphaseflows. Physical Review E, 86(1):016709, jul 2012. doi:10.1103/PhysRevE.86.016709.

S. Gong and P. Cheng. A lattice Boltzmann method for simulation of liquid–vapor phase-change heat transfer. International Journal of Heat and Mass Transfer, 55(17-18):4923–4927, aug 2012. doi:10.1016/j.ijheatmasstransfer.2012.04.037

Q. Li, P. Zhou, and H. J. Yan. Improved thermal lattice Boltzmann model for simulation of liquid-vaporphase change. Physical Review E, 96(6), 2017. doi:10.1103/PhysRevE.96.063303

Relevant papers for MRT collision operator

Q. Li, K. H. Luo, and X. J. Li. Lattice Boltzmann modeling of multiphase flows at large density ratio withan improved pseudopotential model. Physical Review E, 87(5):053301, may 2013. doi:10.1103/PhysRevE.87.053301.

Other interesting papers

Q. Li, Y. Yu, and Z. X. Wen. How does boiling occur in lattice Boltzmann simulations? 093306(May),2020. doi:10.1063/5.0015491.