The module NS of Fluidyn MP offers a suite of solvers for various kinds of flows. Both pressure and density based solvers are available for varying degree of precisions of expected flow. Implicit solver, NS-NT, can simulate steady or low transient flows. NS-MB, semi-implicit time marching solver is very efficient for reaction kinetics or for changing flow patterns. NS-TVD is used when all the equations momentum – energy – State equation need to be solved together such as for highly compressed or high Mach number flows or detonations.              

External and Internal Flows

Fluidyn MP-NS simulates fluid flow in and around complex geometrical configurations.

Several numerical schemes available offer an accurate representation of all kinds of flows, ranging from incompressible to highly compressible flows, from free surface to discrete particle-laden flows and from steady to highly unsteady flows (explosions).

Both pressure and density based fluid solvers can be used. Mesh can be multi-block structured or unstructured (or hybrid) besides being stationary or moving. It can easily handle problems involving non-matching meshes at boundaries or inside the domain.

Turbulent flows

The following turbulence models are available in Fluidyn-MP NS:

  • Standard k-e with compressibility corrections
  • Re-normalization group (RNG) k-e
  • Chen-Kim k-e
  • Mixing length models, Baldwin-Lomax, Cebeci-Smith
  • Large Eddy Simulation using the Smagorinsky’s Sub-Grid Scale model (SGS)

Non-equilibrium law-of-wall condition is used at solid walls.

Multi Phase Flow

Eulerian-Lagrangian and Eulerian-Eulerian models are available for multiphase flows.

Free surface problems are simulated generally by Volume of Fluid (VOF) method. In some cases a Lagrange- Euler coupling can also be used.

For flow through obstructions, both surface porosity (perforated plates) and volume porosity can be solved. Local Thermal Equilibrium (LTE) and Local Thermal Non Equilibrium (LTNE) models are available to simulate heat transfer in porous medium. Anisotropy dispersion model is available for solute transport.

Phenomena like boiling; condensation, melting, and solidification can also be solved.

Reactive Flows

Fluidyn MP uses several different kinds of reaction models depending on the chemical kinetics and turbulence to be accounted for.

Besides gaseous combustion or reaction, it can also work on droplet or free surface combustion.

Deflagration & Detonation

For high rate of chemical kinetics such as deflagration, Fluidyn-MP solves coupled system of momentum and energy equation with a time marching solver.

For detonation of solid explosives, it uses a special density based solver for resolving JWL equations for the explosives. Solver algorithm has been especially developed to build the detonation Chapman-Jouguet front with a minimum number of meshes. Thus a detonation pressure wave, inside a non-spherical 3D geometry of the solid explosives, can also be simulated.  Ignition can have a line or point source, giving rise to either cylindrical or spherical waves.