neptune_cfd

neptune_cfd is the code_saturne extension dedicated to multiphase flow simulation.

Advanced CFD software for two-phase and multiphase flows

neptune_cfd is a multiphase computational fluid dynamics solver developed upon the code_saturne framework. It can be used as a standalone solver or integrated into the SALOME platform, thus providing a comprehensive environment for the setup, execution and analysis of multiphase CFD simulations.

Developed within the framework of the NEPTUNE project, a collaborative research and development initiative involving the main actors of the French nuclear industry (CEA, EDF, Framatome and IRSN, now integrated into ASNR), neptune_cfd is an advanced tool for the simulation of complex two-phase flows in industrial and research applications.

A high-performance Euler-Euler multiphase approach

neptune_cfd relies on a multi-fluid Eulerian approach, enabling the simultaneous modelling of several interacting phases.

This approach is particularly well suited to the simulation of complex phenomena involving:

  • momentum transfer;
  • heat transfer;
  • mass transfer between phases;
  • phase changes;
  • flow regime transitions.

Thanks to its robust and extensible architecture, neptune_cfd can represent a wide range of multiphase phenomena encountered in the nuclear industry, energy, industrial processes and academic research.

Multiphase flow modelling capabilities

neptune_cfd can notably simulate:

Free-surface flows

  • water-air flows;
  • tank filling or draining;
  • wave motion;
  • liquid-gas interactions.

Dispersed flows

  • boiling flows;
  • bubbly flows;
  • particle-laden flows;
  • droplet-laden flows;
  • phase separation and transport.

Complex two-phase flows

  • stratified flow regimes;
  • slug flow regimes;
  • annular flows;
  • transitions between different flow regimes;
  • nuclear thermal-hydraulic phenomena.

Advanced physical models

neptune_cfd includes a comprehensive set of closure laws and physical models to represent:

  • interfacial mass transfer;
  • interfacial heat transfer;
  • interfacial momentum transfer;
  • lift, turbulent dispersion and wall lubrication forces;
  • nucleation and boiling;
  • condensation;
  • phase-change phenomena;
  • multiphase flow regime transitions.

These models accurately reproduce the mechanisms governing industrial two-phase flows.

Applications

Application areas notably include:

  • nuclear thermal-hydraulics;
  • steam generators;
  • cooling systems;
  • water-steam flows;
  • water-air flows;
  • industrial multiphase processes;
  • safety studies;
  • academic research in fluid mechanics.

Availability and licensing

Unlike code_saturne, which is distributed as open-source software, neptune_cfd is not distributed under an open-source licence. Licences may nevertheless be granted to third-party organisations under specific agreements.

For licensing requests or further information: neptune-support@edf.fr