chaos-polymtl/lethe
Nov 2024 – Feb 2026
16 Months active
Languages Used
C++GmshPrmPythonRSTShellcsvprm
Technical Skills
C++CFDCode RefactoringConfigurationConfiguration ManagementDEM
Bruno Blais
PROFILE
Bruno Blais
Bruno Blais developed and maintained the chaos-polymtl/lethe simulation framework over 16 months, delivering 65 features and resolving 38 bugs. He engineered robust CFD-DEM coupling, matrix-free solvers, and dynamic time-stepping, enhancing simulation fidelity and scalability. Using C++ and Python, Bruno refactored core modules for modularity, optimized particle-fluid projection performance, and modernized the codebase for parallel computing with deal.II. His work included rigorous testing, documentation improvements, and CI/CD integration, ensuring reliability across platforms. By addressing numerical stability, memory efficiency, and usability, Bruno enabled reproducible, high-performance simulations, supporting both research and production needs with a focus on maintainability and extensibility.
Overall Statistics
Feature vs Bugs
63%Features
Repository Contributions
195Total
Bugs
38
Commits
195
Features
65
Lines of code
120,266
Activity Months16
Your Network
6 peopleShared Repositories
6
Work History
February 2026
8 Commits • 4 Features
Feb 1, 2026February 2026: Delivered key features and fixes in chaos-polymtl/lethe with business impact-focused outcomes. Implemented a sub-simulation control for DEM time stepping within CFD-DEM, enabling dynamic time-stepping and two stepping modes; fixed a DEM time-step calculation bug in BDF2; improved test coverage and documentation. Optimized memory allocation for the broad search store_candidates, yielding ~10% faster execution without changing results. Fixed matrix-free VANS momentum equation with the missing term and corrected particle-laden fields output, aligning results with the matrix-based solver and updating tests. Refactored 2D dam break example to geometric reinitialization for robustness, added an animation, and updated documentation. Expanded documentation and changelog quality through Doxygen improvements and LaTeX-formatted VANS formulas.
8 Commits • 4 Features
Feb 1, 2026February 2026: Delivered key features and fixes in chaos-polymtl/lethe with business impact-focused outcomes. Implemented a sub-simulation control for DEM time stepping within CFD-DEM, enabling dynamic time-stepping and two stepping modes; fixed a DEM time-step calculation bug in BDF2; improved test coverage and documentation. Optimized memory allocation for the broad search store_candidates, yielding ~10% faster execution without changing results. Fixed matrix-free VANS momentum equation with the missing term and corrected particle-laden fields output, aligning results with the matrix-based solver and updating tests. Refactored 2D dam break example to geometric reinitialization for robustness, added an animation, and updated documentation. Expanded documentation and changelog quality through Doxygen improvements and LaTeX-formatted VANS formulas.
February 2026
January 2026
4 Commits • 2 Features
Jan 1, 2026January 2026: Delivered high-impact stability, performance optimizations, and sustainability enhancements for chaos-polymtl/lethe. Focused on cross-platform reliability, CFD-DEM coupling performance, and community support mechanisms to enable larger-scale simulations and ongoing project funding. The work blends robust engineering with open-source stewardship to maximize business value and long-term sustainability.
January 2026
4 Commits • 2 Features
Jan 1, 2026January 2026: Delivered high-impact stability, performance optimizations, and sustainability enhancements for chaos-polymtl/lethe. Focused on cross-platform reliability, CFD-DEM coupling performance, and community support mechanisms to enable larger-scale simulations and ongoing project funding. The work blends robust engineering with open-source stewardship to maximize business value and long-term sustainability.
December 2025
20 Commits • 3 Features
Dec 1, 2025December 2025 contributed substantial documentation improvements, architectural modernization, and runtime robustness for chaos-polymtl/lethe. Key outcomes include: integrating Res CFD-DEM theory and notation into the documentation; migrating the codebase to deal.II parallel vectors and consolidating vector usage; upgrading the solver backend to deal.II with matrix-free and matrix-based support; improving the VANS CFD-DEM example with implicit drag and Model A; hardening the build and CI on macOS and deprecating RPT solvers; and addressing critical robustness issues to stabilize restarts, ghost handling, and parallel execution. These efforts deliver clearer user guidance, scalable performance on HPC, more reliable simulations, and a cleaner, future-ready architecture.
20 Commits • 3 Features
Dec 1, 2025December 2025 contributed substantial documentation improvements, architectural modernization, and runtime robustness for chaos-polymtl/lethe. Key outcomes include: integrating Res CFD-DEM theory and notation into the documentation; migrating the codebase to deal.II parallel vectors and consolidating vector usage; upgrading the solver backend to deal.II with matrix-free and matrix-based support; improving the VANS CFD-DEM example with implicit drag and Model A; hardening the build and CI on macOS and deprecating RPT solvers; and addressing critical robustness issues to stabilize restarts, ghost handling, and parallel execution. These efforts deliver clearer user guidance, scalable performance on HPC, more reliable simulations, and a cleaner, future-ready architecture.
December 2025
November 2025
27 Commits • 5 Features
Nov 1, 2025November 2025 highlights for chaos-polymtl/lethe: Delivered versatile particle–fluid coupling and scalable CFD-DEM integration, enabling robust simulations across explicit, semi-implicit, and fully implicit modes, with a new momentum-exchange coefficient to improve physical fidelity. Introduced matrix-free CFD-DEM and matrix-free particle–fluid coupling (QCM projection), significantly improving performance and scalability for large particle counts. Expanded and hardened the test suite (sedimentation tests) and moved core parameters to support new coupling modes, boosting reliability and reproducibility. Fixed critical reliability issues (Apple CLANG compilation due to missing includes; boundary PVD write bug; particle-output naming), improved code quality (Clang-Tidy V20 warnings, indentation), and stabilized time stepping (adaptive CFL and time-step sanitization). Strengthened CI/CD and documentation tooling (Release CI on GitHub Actions, Clang-Tidy badge, prmindent CI, Doxygen agent) and improved test infrastructure and contributor recognition.
November 2025
27 Commits • 5 Features
Nov 1, 2025November 2025 highlights for chaos-polymtl/lethe: Delivered versatile particle–fluid coupling and scalable CFD-DEM integration, enabling robust simulations across explicit, semi-implicit, and fully implicit modes, with a new momentum-exchange coefficient to improve physical fidelity. Introduced matrix-free CFD-DEM and matrix-free particle–fluid coupling (QCM projection), significantly improving performance and scalability for large particle counts. Expanded and hardened the test suite (sedimentation tests) and moved core parameters to support new coupling modes, boosting reliability and reproducibility. Fixed critical reliability issues (Apple CLANG compilation due to missing includes; boundary PVD write bug; particle-output naming), improved code quality (Clang-Tidy V20 warnings, indentation), and stabilized time stepping (adaptive CFL and time-step sanitization). Strengthened CI/CD and documentation tooling (Release CI on GitHub Actions, Clang-Tidy badge, prmindent CI, Doxygen agent) and improved test infrastructure and contributor recognition.
October 2025
13 Commits • 4 Features
Oct 1, 2025October 2025 performance summary for chaos-polymtl/lethe: delivered stability and performance improvements across CFD-DEM integration, force modeling, CI/QA, and documentation. Highlights include adaptive time-step support, robust timer behavior, a focused refactor of fluid-particle forces, modernized CI workflows, and memory-efficient data structures that improve runtime efficiency and reproducibility.
13 Commits • 4 Features
Oct 1, 2025October 2025 performance summary for chaos-polymtl/lethe: delivered stability and performance improvements across CFD-DEM integration, force modeling, CI/QA, and documentation. Highlights include adaptive time-step support, robust timer behavior, a focused refactor of fluid-particle forces, modernized CI workflows, and memory-efficient data structures that improve runtime efficiency and reproducibility.
October 2025
September 2025
27 Commits • 11 Features
Sep 1, 2025September 2025 – Chaos-polymtl/lethe: concise monthly summary focusing on business value and technical achievements.
September 2025
27 Commits • 11 Features
Sep 1, 2025September 2025 – Chaos-polymtl/lethe: concise monthly summary focusing on business value and technical achievements.
August 2025
10 Commits • 3 Features
Aug 1, 2025August 2025 monthly summary for chaos-polymtl/lethe. Delivered a more robust and extensible simulation framework by introducing a new VOF initialization via geometric redistanciation, generalizing field projections with a ParticleProjector, and executing a broad suite of code quality improvements. Also strengthened resilience for METIS-absent runs and matrix-free TGV examples, reducing edge-case failures and clarifying usage in docs. Impact highlights include improved numerical accuracy and stability of the VOF initialization, a flexible projection mechanism for particle-laden fields, and a cleaner, better-documented codebase that shortens onboarding and future maintenance effort. The work supports faster feature delivery and more reliable simulations in production runs. Key technologies and skills demonstrated: C++/MPI parallelism, refactoring to support generic projections, test and doc automation, Doxygen improvements, and build/test configuration tuning.
10 Commits • 3 Features
Aug 1, 2025August 2025 monthly summary for chaos-polymtl/lethe. Delivered a more robust and extensible simulation framework by introducing a new VOF initialization via geometric redistanciation, generalizing field projections with a ParticleProjector, and executing a broad suite of code quality improvements. Also strengthened resilience for METIS-absent runs and matrix-free TGV examples, reducing edge-case failures and clarifying usage in docs. Impact highlights include improved numerical accuracy and stability of the VOF initialization, a flexible projection mechanism for particle-laden fields, and a cleaner, better-documented codebase that shortens onboarding and future maintenance effort. The work supports faster feature delivery and more reliable simulations in production runs. Key technologies and skills demonstrated: C++/MPI parallelism, refactoring to support generic projections, test and doc automation, Doxygen improvements, and build/test configuration tuning.
August 2025
July 2025
18 Commits • 6 Features
Jul 1, 2025July 2025 summary for chaos-polymtl/lethe: delivered major documentation and usability enhancements, validated new workflows, expanded example coverage, modernized legacy components, and prepared for future library compatibility. Key achievements include: 1) Documentation improvements across Lethe (installation and usage guidance, references, and solver guidance) with seven related commits (Rorqual installation updates, typo fixes, table corrections, added references, and clarified deal.II guidance). 2) Validation tooling enhancements, adding Lucille compute node support, a new test case, and non-interactive execution to streamline validation workflows. 3) A new end-to-end 3D turbulent flow around a cylinder example (Re=3900) with documentation, parameter files, and post-processing scripts for drag, Strouhal, and pressure validation. 4) Deprecation and modernization: removal of the legacy gas-solid-spouted-bed example in favor of an advanced gas-solid-spouted-rectangular-bed with updated documentation. 5) Numerical methods robustness and deal.II compatibility: updates to default matrix-free parameters, void fraction solver tolerances, 64-bit index support, and compatibility with deal.II 9.8, including removal of obsolete paths; plus a CI adjustment to disable Docker image builds pending deal.II 9.7 release for stability.
July 2025
18 Commits • 6 Features
Jul 1, 2025July 2025 summary for chaos-polymtl/lethe: delivered major documentation and usability enhancements, validated new workflows, expanded example coverage, modernized legacy components, and prepared for future library compatibility. Key achievements include: 1) Documentation improvements across Lethe (installation and usage guidance, references, and solver guidance) with seven related commits (Rorqual installation updates, typo fixes, table corrections, added references, and clarified deal.II guidance). 2) Validation tooling enhancements, adding Lucille compute node support, a new test case, and non-interactive execution to streamline validation workflows. 3) A new end-to-end 3D turbulent flow around a cylinder example (Re=3900) with documentation, parameter files, and post-processing scripts for drag, Strouhal, and pressure validation. 4) Deprecation and modernization: removal of the legacy gas-solid-spouted-bed example in favor of an advanced gas-solid-spouted-rectangular-bed with updated documentation. 5) Numerical methods robustness and deal.II compatibility: updates to default matrix-free parameters, void fraction solver tolerances, 64-bit index support, and compatibility with deal.II 9.8, including removal of obsolete paths; plus a CI adjustment to disable Docker image builds pending deal.II 9.7 release for stability.
June 2025
4 Commits • 1 Features
Jun 1, 2025June 2025 monthly performance summary for chaos-polymtl/lethe. Focused on delivering high-impact solver enhancements and reliability fixes that improve accuracy, flexibility, and production readiness for CFD-DEM simulations.
4 Commits • 1 Features
Jun 1, 2025June 2025 monthly performance summary for chaos-polymtl/lethe. Focused on delivering high-impact solver enhancements and reliability fixes that improve accuracy, flexibility, and production readiness for CFD-DEM simulations.
June 2025
May 2025
6 Commits • 3 Features
May 1, 2025May 2025 monthly summary for chaos-polymtl/lethe focusing on feature delivery, stability fixes, and preparation for release. Highlights include experimental DG VOF solver integration, enhancements to the mortar coupling interface with GMSH support, a data-file fix for the 3D rotating-drum example to ensure reproducibility, and release-management/workflow improvements (code formatting, contributor updates, and v1.0.1 changelog). Together, these efforts advance research capabilities in surface-tension/VOF modeling, improve geometry handling for rotor-stator couplings, and strengthen reliability and documentation for future production use.
May 2025
6 Commits • 3 Features
May 1, 2025May 2025 monthly summary for chaos-polymtl/lethe focusing on feature delivery, stability fixes, and preparation for release. Highlights include experimental DG VOF solver integration, enhancements to the mortar coupling interface with GMSH support, a data-file fix for the 3D rotating-drum example to ensure reproducibility, and release-management/workflow improvements (code formatting, contributor updates, and v1.0.1 changelog). Together, these efforts advance research capabilities in surface-tension/VOF modeling, improve geometry handling for rotor-stator couplings, and strengthen reliability and documentation for future production use.
April 2025
8 Commits • 2 Features
Apr 1, 2025April 2025 monthly summary for chaos-polymtl/lethe: Delivered targeted fixes and usability improvements that enhanced numerical reliability, testing robustness, and user experience, while maintaining a clear focus on business value and maintainability.
8 Commits • 2 Features
Apr 1, 2025April 2025 monthly summary for chaos-polymtl/lethe: Delivered targeted fixes and usability improvements that enhanced numerical reliability, testing robustness, and user experience, while maintaining a clear focus on business value and maintainability.
April 2025
March 2025
16 Commits • 2 Features
Mar 1, 2025March 2025 was focused on delivering foundational capabilities for performance-oriented simulations in chaos-polymtl/lethe, stabilizing core numerical routines, and tightening CI reliability. The work laid groundwork for robust matrix-free VANS modeling, improved solver stability on distorted grids, and ensured reproducible, high-quality results in daily development cycles.
March 2025
16 Commits • 2 Features
Mar 1, 2025March 2025 was focused on delivering foundational capabilities for performance-oriented simulations in chaos-polymtl/lethe, stabilizing core numerical routines, and tightening CI reliability. The work laid groundwork for robust matrix-free VANS modeling, improved solver stability on distorted grids, and ensured reproducible, high-quality results in daily development cycles.
February 2025
5 Commits • 3 Features
Feb 1, 2025February 2025: Key feature deliveries, critical bug fixes, and improvements across chaos-polymtl/lethe, with a focus on fidelity, usability, and visualization reliability. Delivered four high-impact items spanning DEM fidelity, Linux onboarding, new physics examples, and 3D-consistent outputs for 2D simulations. These efforts enhance model realism, reproducibility, and cross-platform usability, delivering tangible business value for researchers and engineers relying on Lethe.
5 Commits • 3 Features
Feb 1, 2025February 2025: Key feature deliveries, critical bug fixes, and improvements across chaos-polymtl/lethe, with a focus on fidelity, usability, and visualization reliability. Delivered four high-impact items spanning DEM fidelity, Linux onboarding, new physics examples, and 3D-consistent outputs for 2D simulations. These efforts enhance model realism, reproducibility, and cross-platform usability, delivering tangible business value for researchers and engineers relying on Lethe.
February 2025
January 2025
9 Commits • 3 Features
Jan 1, 2025January 2025 monthly summary for chaos-polymtl/lethe: Delivered templated DEM properties indexing to support multiple property sets and CFD-DEM interoperability, enabling heat transfer within particles and conversion between DEM and CFD-DEM ParticleHandlers for decoupled meshes. Fixed visualization and restart data reliability for DEM/CFD-DEM simulations, improving ParaView output stability. Strengthened test infrastructure with standardized restart test naming and removal of a font dependency to boost reliability. Aligned CI/build environment with deal.II 9.6.0 and prepared release readiness with version bumps and updated installation docs. These changes collectively improve modularity, cross-compatibility, reliability, and faster release cycles.
January 2025
9 Commits • 3 Features
Jan 1, 2025January 2025 monthly summary for chaos-polymtl/lethe: Delivered templated DEM properties indexing to support multiple property sets and CFD-DEM interoperability, enabling heat transfer within particles and conversion between DEM and CFD-DEM ParticleHandlers for decoupled meshes. Fixed visualization and restart data reliability for DEM/CFD-DEM simulations, improving ParaView output stability. Strengthened test infrastructure with standardized restart test naming and removal of a font dependency to boost reliability. Aligned CI/build environment with deal.II 9.6.0 and prepared release readiness with version bumps and updated installation docs. These changes collectively improve modularity, cross-compatibility, reliability, and faster release cycles.
December 2024
3 Commits • 3 Features
Dec 1, 2024December 2024 — chaos-polymtl/lethe: Key features delivered and architectural improvements focused on release readiness and future performance. Principal deliverables include: Lethe v1.0 Release Documentation and Preparation (CHANGELOG updated to document release date and production-readiness/testing emphasis); Void Fraction Calculation Refactor and Unused Bounding Removal (void fraction moved to a separate subequation solver; deprecated bounding removed to improve modularity and pave the way for matrix-free implementations); Automated Validation Framework with Predefined Test Cases (new automated validation system with known-solution examples, performance reporting, and validation scripts). No explicit major bug fixes were recorded in this period based on the provided data. Overall impact: accelerated readiness for v1.0, improved code modularity and test coverage, and a foundation for scalable solver architectures. Technologies/skills demonstrated: release engineering, modular refactoring, test automation, performance reporting, and documentation.
3 Commits • 3 Features
Dec 1, 2024December 2024 — chaos-polymtl/lethe: Key features delivered and architectural improvements focused on release readiness and future performance. Principal deliverables include: Lethe v1.0 Release Documentation and Preparation (CHANGELOG updated to document release date and production-readiness/testing emphasis); Void Fraction Calculation Refactor and Unused Bounding Removal (void fraction moved to a separate subequation solver; deprecated bounding removed to improve modularity and pave the way for matrix-free implementations); Automated Validation Framework with Predefined Test Cases (new automated validation system with known-solution examples, performance reporting, and validation scripts). No explicit major bug fixes were recorded in this period based on the provided data. Overall impact: accelerated readiness for v1.0, improved code modularity and test coverage, and a foundation for scalable solver architectures. Technologies/skills demonstrated: release engineering, modular refactoring, test automation, performance reporting, and documentation.
December 2024
November 2024
17 Commits • 10 Features
Nov 1, 2024November 2024 monthly recap for chaos-polymtl/lethe focusing on business value, performance improvements, and technical achievements across core solvers and examples.
November 2024
17 Commits • 10 Features
Nov 1, 2024November 2024 monthly recap for chaos-polymtl/lethe focusing on business value, performance improvements, and technical achievements across core solvers and examples.
Activity
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Quality Metrics
Correctness93.4%
Maintainability90.6%
Architecture89.4%
Performance86.2%
AI Usage20.8%
Skills & Technologies
Programming Languages
BashC++CMakeDataDockerfileGmshHTMLMarkdownPerlPrm
Technical Skills
Adaptive Time-SteppingAssertion HandlingAutomationBug FixingBuild SystemBuild System ConfigurationBuild SystemsC++C++ DevelopmentC++ developmentC++ programmingCFDCFD-DEMCFD-DEM SimulationCFD-DEM coupling
Repositories Contributed To
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