quokka-astro/quokka
Dec 2025 – Mar 2026
4 Months active
Languages Used
C++
Technical Skills
C++Computational Fluid DynamicsNumerical MethodsPhysics SimulationC++ programmingfluid dynamics
mxchen39
PROFILE
Mxchen39
Developed advanced dust and gas-dust interaction features for the quokka-astro/quokka simulation codebase, focusing on realistic modeling of astrophysical flows. Leveraging C++ and numerical methods, implemented a dust module with coupled dynamics, frictional heating, and Strang-split time integration, along with runtime controls for stability. Enhanced simulation flexibility by introducing user-defined dust stopping times and implicit Picard iteration updates, while improving hydro accuracy through corrected artificial viscosity handling. Addressed MPI reliability issues in parallel dust simulations, stabilized test results, and expanded CI coverage. Added a dedicated dust density floor and validation logic, strengthening robustness and ensuring accurate, scalable scientific computing workflows.
Overall Statistics
Feature vs Bugs
60%Features
Repository Contributions
5Total
Bugs
2
Commits
5
Features
3
Lines of code
6,551
Activity Months4
Your Network
6 peopleWork History
March 2026
1 Commits • 1 Features
Mar 1, 2026March 2026 monthly summary for quokka repository focusing on feature delivery, robustness, and impact. Key accomplishments include the introduction of a dedicated dust density floor for QUOKKA dust, robustness validation to prevent invalid dust states, and preparation for broader test coverage and CI validation. The work enhances realism in dust dynamics modeling and stability of simulations, with clear business value for research accuracy and reliable runtime behavior.
1 Commits • 1 Features
Mar 1, 2026March 2026 monthly summary for quokka repository focusing on feature delivery, robustness, and impact. Key accomplishments include the introduction of a dedicated dust density floor for QUOKKA dust, robustness validation to prevent invalid dust states, and preparation for broader test coverage and CI validation. The work enhances realism in dust dynamics modeling and stability of simulations, with clear business value for research accuracy and reliable runtime behavior.
March 2026
February 2026
1 Commits
Feb 1, 2026February 2026 monthly summary for quokka-astro/quokka focused on reliability and test stabilization of MPI-based dust simulations.
February 2026
1 Commits
Feb 1, 2026February 2026 monthly summary for quokka-astro/quokka focused on reliability and test stabilization of MPI-based dust simulations.
January 2026
2 Commits • 1 Features
Jan 1, 2026Monthly summary for 2026-01: Delivered significant physics enhancements and bug fixes in quokka-astro/quokka. Implemented User-Defined Dust Stopping Time Feature with an optional Picard iteration for implicit dust–gas drag updates and a refactored stopping time interface to support problem-defined stopping times, including new runtime knobs (dust.enable_iter_stoptime, dust.print_iteration_counts). Added tests and triggered GPU tests. Fixed artificial viscosity direction bug in the hydro system by using F_canonical to store intermediate fluxes and applying correct momentum permutations, improving hydro accuracy. The changes increase flexibility, stability, and accuracy of simulations, enabling Kwok-based stopping time with optional corrections and better momentum conservation.
2 Commits • 1 Features
Jan 1, 2026Monthly summary for 2026-01: Delivered significant physics enhancements and bug fixes in quokka-astro/quokka. Implemented User-Defined Dust Stopping Time Feature with an optional Picard iteration for implicit dust–gas drag updates and a refactored stopping time interface to support problem-defined stopping times, including new runtime knobs (dust.enable_iter_stoptime, dust.print_iteration_counts). Added tests and triggered GPU tests. Fixed artificial viscosity direction bug in the hydro system by using F_canonical to store intermediate fluxes and applying correct momentum permutations, improving hydro accuracy. The changes increase flexibility, stability, and accuracy of simulations, enabling Kwok-based stopping time with optional corrections and better momentum conservation.
January 2026
December 2025
1 Commits • 1 Features
Dec 1, 2025December 2025: Implemented Dust Transport and Gas-Dust Interaction Simulation in Quokka (quokka-astro/quokka). Introduced a dust module enabling coupled gas–dust dynamics with drag coupling and optional frictional heating, expanding physical realism for dusty astrophysical flows. The feature adds dust-specific conserved variables, a dedicated dust Riemann solver, and Strang-split time integration to robustly advance dust and gas together. Runtime controls (alpha: inverse stopping time; omega: frictional heating strength) and a CFL-based timestep were implemented to ensure numerical stability and performance. Added comprehensive tests for the new physics and triggered GPU tests as part of CI. Impact: Enables more accurate modeling of dust transport, drag heating, and dust–gas momentum exchange in simulations, improving predictive capability for disk and ISM workflows. Technologies/Skills Demonstrated: C++ AMR/Multifab data structures, dust–gas coupling physics, Strang splitting, Riemann solvers, implicit-explicit time integration, runtime parameterization, testing/CI, GPU test readiness.
December 2025
1 Commits • 1 Features
Dec 1, 2025December 2025: Implemented Dust Transport and Gas-Dust Interaction Simulation in Quokka (quokka-astro/quokka). Introduced a dust module enabling coupled gas–dust dynamics with drag coupling and optional frictional heating, expanding physical realism for dusty astrophysical flows. The feature adds dust-specific conserved variables, a dedicated dust Riemann solver, and Strang-split time integration to robustly advance dust and gas together. Runtime controls (alpha: inverse stopping time; omega: frictional heating strength) and a CFL-based timestep were implemented to ensure numerical stability and performance. Added comprehensive tests for the new physics and triggered GPU tests as part of CI. Impact: Enables more accurate modeling of dust transport, drag heating, and dust–gas momentum exchange in simulations, improving predictive capability for disk and ISM workflows. Technologies/Skills Demonstrated: C++ AMR/Multifab data structures, dust–gas coupling physics, Strang splitting, Riemann solvers, implicit-explicit time integration, runtime parameterization, testing/CI, GPU test readiness.
Activity
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Quality Metrics
Correctness88.0%
Maintainability80.0%
Architecture84.0%
Performance80.0%
AI Usage36.0%
Skills & Technologies
Programming Languages
C++
Technical Skills
C++C++ developmentC++ programmingComputational Fluid DynamicsNumerical MethodsPhysics ModelingPhysics SimulationSimulation Developmentfluid dynamicsnumerical methodsparallel computingscientific computing
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