Lattice Boltzmann CFD suite ProLB release 3.3 - release Title

ProLB v3.3 : a new milestone

Let's review the new features since v 3.0

Version 3.0 was released in May 2023. ProLB evolves at a pace of one version every six months; consequently, versions 3.1 and 3.2 were released at the end of 2023 and mid-2024, respectively. The new version 3.3 has just been released and represents a significant milestone in the integration and maturation of ProLB’s new features. We felt it was important to review these developments since version 3.0.

The contributions of the European SCALABLE project, which concluded in 2024, enabled progress in parallel computing performance. The high-Mach physical scheme has been integrated into the GUI, validated, and is fully operational, allowing for the simulation of complex flows up to Mach 1. Shockwave flows are currently undergoing validation. Several GUI and solver enhancements, particularly related to outputs, have improved the overall user experience. New physics capabilities are making their debut (in beta) in ProLB: multi-species flows and atmospheric boundary layers.

A more detailed description of these features is provided below.

Feature Highlights

Lattice Boltzmann CFD suite ProLB release 3.3 - ihm prolb lbpre

High Mach setup available

  • Easily switch to High Mach while preserving your setup
  • New Total Pressure/ Total Temperature boundary condition as part of the High Mach setup

Better initialization with optimal field mapping

  • Interpolation artefacts are reduced
  • Shorter adaptation time to reach physical state

Automatic median shapes for rotating domains

  • Median shapes are now automatically computed at the creation of a rotating domain
  • Avoid duplicates when writing results on rotating domains

Absolute mass flow rate boundary condition

  • Mass flow rate boundary condition can now be setup with an absolute value
  • No need to know the surface of inlet anymore

A new integrated quantity

A new integrated quantity is available in the recordings : the heatflux on any wet surface.

Quality of life improvements

Random colors for new geometries, easier selections etc.

Overall

  • Improved Efficiency (new MPI exchanger, reduction of data transfer, preprocessing optimizations, better efficiency for recordings  etc.)
  • Optimal compression for checkpoints : checkpoints creation is quicker

  • On-the-fly merging of probe outputs : probes output are now directly written in a single PRF file, which is easier to monitor

  • Detailed backflow handling on outlet boundary conditions

  • Scalability assessed on a landing gear industrial case up to 20000 cpus :

Lattice Boltzmann CFD suite ProLB release 3.3 - scalability

Low Mach Physics

  • New advection scheme for low Mach thermal physics (HRRTherm and uHRR) with better conservativity
  • Improved wall heat flux computation for natural convection (models with very small Y+)

  • Improved mass conservation close to the walls for low Mach thermal physics
  • Perfect gas scheme acceleration : timestep increase using an automatic PGS (Pressure Gradient Scaling) method

  • Absorbing regions available for perfect gas models

High Mach Physics

  • Now fully integrated in ProLB pipeline
  • Improved accuracy of the gradient computation at mesh refinement transitions

  • Absorbing regions available

  • Optionnally, activate a high order interpolation on mobile/fixed nodes

Lattice Boltzmann CFD suite ProLB release 3.3 - highmachJet

example of a jet instantaneous velocity field, Mach number of 0.9, computed in ProLB 3.3 High Mach scheme

New multi-species physics

Applications : H2 leaks modelling, H2 risks assessment, pollutant dispersion, tracers

  1. Numerical models derived from coupling classical LBM with finite volumes

    • LBM: Conservation of mass, conservation of momentum.
    • Hybrid finite volume/LBM: Conservation of species concentration.
    • Two models available
  2. Model 1 :Multi-species passive scalar (Boussinesq approximation):

    • The species are treated as passive scalars.
    • The local thermodynamic properties correspond to a reference species.
    • The pressure is equal to the LBM pressure.
    • Well suited when a species is dominant in the mixture
    • Very efficient simulation : well-suited for long-term simulations (several hundreds of seconds of physical time)
  3. Model 2 : Multi-species low Mach ideal gas:

    • The local thermodynamic properties depend on the species composition.
    • The pressure follows the ideal gas equation of state.
    • No restriction over the mixture composition
    • Very precise : well-suited to describe short-term dynamics (transitional phases)

Those models are compatible with all thermal features in ProLB

Those models are compatible with all other features (porous media, rotating domains etc.)

Lattice Boltzmann CFD suite ProLB release 3.3 - multispe

Sandia’s 1m diameter helium plume

Taha et al. 2024 Mostafa Taha, Song Zhao, Aymeric Lamorlette, Jean-Louis Consalvi, Pierre Boivin, Large eddy simulation of fire-induced flows using Lattice-Boltzmann methods, International Journal of Thermal Sciences,Volume 197,2024

BETA features

  • Beta version of a brand new atmospheric boundary layer model

Lattice Boltzmann CFD suite ProLB release 3.3 - ABL_qcrit
Lattice Boltzmann CFD suite ProLB release 3.3 - ABL_velo

Test case with a neutral atmospheric boundary layer : Shinjuku area, Tokyo – performed by M2P2 lab (Aix-Marseille University)

Buffa, Elisa, Jérôme Jacob, and Pierre Sagaut. “Lattice-Boltzmann-based large-eddy simulation of high-rise building aerodynamics with inlet turbulence reconstruction.” Journal of Wind Engineering and Industrial Aerodynamics 212 (2021): 104560.