ALADIN Galactic Plasma Dynamics : 3D Cylindrical Plasma Driver — Architecture and Infrastructure Validation

ALADIN Galactic Plasma Dynamics 3D Cylindrical Plasma Driver — Architecture and Infrastructure Validation Overview ALADIN Galactic Plasma Dynamics is a computational plasma simulation framework designed to provide a modular infrastructure for investigating plasma behaviour and magnetohydrodynamic (MHD) processes in astrophysical environments, particularly galactic disks. Version 1.0 introduces a three-dimensional cylindrical-coordinate driver architecture, providing the geometric infrastructure, simulation state management, numerical execution framework, time integration, boundary handling, diagnostics and memory management required for future physics-kernel development. The framework is designed around a single-file Python implementation, with support for NumPy-based execution and a CuPy/CUDA backend architecture. The primary objective of this release is to establish and validate the computational infrastructure required for three-dimensional cylindrical plasma simulations. Scientific and computational scope The framework is designed to support the investigation of: Galactic plasma dynamics. Magnetohydrodynamic processes. Magnetic-field evolution and topology. Lorentz forces and plasma interactions. Toroidal magnetic fields and magnetic tension. Radial and vertical plasma dynamics. Hall-MHD effects. Gyrotropic plasma pressure and heat-flux modelling. Constrained-transport magnetic-field evolution. Magnetically influenced galactic disk dynamics. Gravitationally influenced plasma configurations. These represent the intended physics scope of the framework. Not all listed physical processes are fully implemented or validated in this release. Software architecture ALADIN v2.1 includes the following infrastructure components: Configuration Manager — simulation parameters, physical constants, numerical settings and execution options. Geometry Manager — cylindrical-coordinate geometry, radial and angular coordinates, cell volumes, face areas and edge lengths. Grid Manager — three-dimensional computational grid with ghost cells and staggered field locations. State Registry — centralized management of fluid, magnetic, moment and diagnostic variables. Boundary Manager — periodic, outflow and cylindrical-axis boundary infrastructure. Memory Pool Manager — memory allocation and management for NumPy and CuPy execution. Kernel Backend — computational backend abstraction and CUDA execution infrastructure. Operator Registry — registration and organization of computational operators. Execution Controller — ordered operator execution. Time Manager — timestep management and numerical constraints. SSP-RK3 Integrator — third-order strong-stability-preserving Runge–Kutta integration infrastructure. Gravity Manager — external gravitational potential and acceleration infrastructure. Diagnostics Manager — mass, magnetic-energy and other simulation diagnostics. Checkpoint Manager — simulation-state saving and recovery. Health Manager — numerical-state checks and failure detection. Results Manager — output and radial-profile reporting. ALADIN Driver — central orchestration of the simulation lifecycle. Kernel architecture The driver establishes an eight-operator execution sequence: UCT Entropy Geometry HLLD X HLLD Y HLLD Z EMF Curl GLM The architecture separates simulation management and state ownership from individual computational operators. This allows physics kernels to be developed, tested and integrated within a consistent driver infrastructure. Important: In this release, the operator architecture is established, but the physics operators remain placeholders or incomplete implementations. The sequence describes the intended computational architecture, not a claim that all eight physical algorithms are operational. Infrastructure validation The v2.1 validation suite reports: 119 tests passed — 0 failed. The reported test coverage includes: Cylindrical geometry and volume calculations. Grid dimensions and ghost-cell allocation. Staggered-grid field shapes. State registration and memory allocation. Operator registration and execution ordering. SSP-RK3 manufactured-solution testing. Periodic boundary conditions. Cylindrical-axis boundary handling and parity checks. Gravitational potential and acceleration checks. Checkpoint saving and recovery. Numerical health checks. Equilibrium-disk initialization and state validity. Magnetic-field state allocation and integration-related checks. CUDA allocation and kernel-launch checks. Volume-weighted mass diagnostics. Magnetic-energy diagnostic checks. Angular-momentum diagnostic checks. Divergence-related field infrastructure. Resolution and repeatability checks. Restart and recovery testing. Timestep bounds and geometric-source checks. Unit-scale and gravitational consistency checks. Driver initialization, execution and lifecycle completion. A 64 × 64 × 64 NumPy-based equilibrium-disk initialization and five-step driver execution also completed successfully. These results validate the tested infrastructure and manufactured behaviours. They do not establish the physical accuracy or conservation properties of a complete MHD simulation. Current development status and limitations ALADIN v2.1 is an architecture and infrastructure release. The following physics benchmarks remain pending: Hydrodynamic blast-wave benchmark. Alfvén-wave propagation. Magnetic induction benchmark. Cylindrical Z-pinch benchmark. Rotating-disk equilibrium. Constrained-transport magnetic-flux conservation. Full MHD convergence. Magnetorotational instability (MRI). Hall-MRI. These benchmarks are not claimed as passed or physically validated in this release. The full implementation and verification of the physical kernels, conservative evolution, magnetic-field integration and coupled plasma dynamics are part of subsequent development. Reproducibility The release includes the ALADIN v1.0 Python implementation and its associated validation material. The reported validation environment includes NumPy-based execution and CUDA/CuPy infrastructure testing. Users should consult the source configuration and validation scripts for the exact execution settings and test procedures. Future development Future versions aim to integrate and validate the physical computational kernels, improve conservative MHD evolution, develop the gyrotropic plasma closure, and establish a complete suite of cylindrical plasma and astrophysical benchmarks. ALADIN Galactic Plasma Dynamics is intended as an evolving computational framework for exploring plasma processes in astrophysical systems. Release: v2.1Release scope: Architecture and Infrastructure ValidationPhysics benchmark status: Pending