pyHiVAS: A Python-Based
High-Speed Vehicle Aerodynamic Solver

Continuum Solver (CFD)

• • The continuum module resolves high-speed compressible flows in near-continuum regimes using classical CFD techniques. 

  • Compressible Navier–Stokes equations

Rarefied Gas Solvers (DSMC / FP / BGK) 

• For non-equilibrium regimes, pyHiVAS incorporates particle-based kinetic solvers capable of capturing molecular-level physics beyond the Navier–Stokes limit.

• Direct Simulation Monte Carlo (DSMC): Stochastic particle-based solution of the Boltzmann equation 

• Fokker–Planck / BGK-type Particle Solvers: Reduced kinetic models for efficient treatment of transition regimes 

Solid Particle Solvers (DEM-based)

• To model gas–particle interactions, pyHiVAS is designed to couple gas dynamics with solid particle solvers.

• Discrete Element Method (DEM) for solid particle motionn 

Hybrid Coupling Strategies

• pyHiVAS supports multiple hybrid coupling approaches to ensure stable and physically consistent multiscale simulations.

• Hybrid CFD–DSMC Coupling

• Hybrid FP/BGK–DSMC Coupling 

Python-Based Design Philosophy

• pyHiVAS is developed entirely in Python with a strong emphasis on clarity, modularity, and extensibility.

• Readable and modular object-oriented code structure

• Performance acceleration using NumPy and Numba (JIT compilation)

• MPI-based parallelization for large-scale simulations