At present, PLUTO can solve different systems of conservation laws in 1, 2 or 3 dimensions. The four basic physics modules are

- Classical hydrodynamics (Euler equations, HD)
- Magnetohydrodynamics (MHD)
- Special Relativistic hydrodynamics (RHD)
- Special Relativistic MHD (RMHD)

On top of these, different physical processes can be enabled:

- Non ideal dissipative processes: Viscosity / Thermal conduction / Resistivity
- Optically thin radiative losses including atomic / molecular cooling
- Ionization / recombination chemical reaction network
- Different equations of state: Isothermal / Ideal / Synge / general non-constant gamma-law
- Fixed gravity
- Shearing box equations

Equations are discretized and solved on structured meshes supporting

- Static or adaptive mesh refinement
- Different coordinate systems: Cartesian / Cylindrical Axisymmetric / Polar / Spherical
- Uniform or stretched grids

Both serial and massively parallel computations on distributed memory architectures are possible.

The concept of modularity applies not only to the type of equation being solved but also to the capability of enabling different numerical algorithms to be employed and combined in different contexts and different components.

PLUTO solves the fluid equations by means of shock-capturing Godunov-type methods adopting a conservative discretization based on finite volume or finite difference methods. In this formulation interface fluxes are computed by solving a Riemann problem between left and right interface states. A typical time step cycle consists of a i) an explicit time-marching algorithm, ii) a piece-wise reconstruction scheme, iii) a Riemann solver.

For each step, different options can be indipendently selected from:

__Time stepping__:

- RK2, RK3, Characteristic Tracing, or MUSCL-Hancock.

- Super-Time-Stepping to speed-up explicit time-stepping for parabolic terms

- FARGO scheme for orbital advection of (magnetized) shear flows

__Reconstruction__: 2nd-order slope-limited TVD, PPM, WENO and MP5

__Riemann Solvers__: Two-Shocks, Roe, HLLD, HLLC, HLL and Lax-Friedrichs;

In addition, MHD and relativistic MHD are evolved by selecting different strategies to enforce the divergence-free condition, including Constrained transport (CT) / hyperbolic divergence cleaning / Powell's 8 wave formulation.

Please refer to the documentation page for more information.

(C) 2007-2015 The PLUTO Development Team