diff --git a/doc/src/Howto_rheo.rst b/doc/src/Howto_rheo.rst index 748c91845b..e9e0861dc3 100644 --- a/doc/src/Howto_rheo.rst +++ b/doc/src/Howto_rheo.rst @@ -1,9 +1,9 @@ Reproducing hydrodynamics and elastic objects (RHEO) ==================================================== -The RHEO package is built around an implementation of smoothed particle -hydrodynamics (SPH) coupled to the :doc:`BPM package ` to model -solid elements of a system. The SPH solver supports many advanced options +The RHEO package is a hybrid implementation of smoothed particle +hydrodynamics (SPH) for fluid flow, coupled to the :doc:`BPM package ` to model +solid elements. RHEO combines these methods to enable mesh-free modeling of multiphase material systems. The SPH solver supports many advanced options including reproducing kernels, particle shifting, free surface identification, and solid surface reconstruction. To model fluid-solid systems, the status of particles can dynamically change between a fluid and solid state, e.g. during @@ -23,14 +23,14 @@ instance of :doc:`fix rheo/pressure ` and of state and viscosity model, respectively. Optionally, one can model a heat equation with :doc:`fix rheo/thermal`, which also allows the user to specify equations for a particle's thermal conductivity, specific heat, -latent heat, and melting temperature. Fix rheo must be defined prior to all +latent heat, and melting temperature. The ordering of these fixes in an an input script matters. Fix rheo must be defined prior to all other RHEO fixes. Typically, RHEO requires atom style rheo. In addition to typical atom properties like positions and forces, particles store a local density, viscosity, pressure, and status. If thermal evolution is modeled, one must use atom style rheo/thermal which also include a local temperature and -conductivity. The status variable uses bitmasking to track various +thermal conductivity. RHEO style atoms also have a status variable which uses bitmasking to track various properties of a particle such as its current state of matter (fluid or solid) and its location relative to a surface. Many of these properties (and others) can be easily accessed using @@ -39,14 +39,14 @@ can be easily accessed using Fluid interactions, including pressure forces, viscous forces, and heat exchange, are calculated using :doc:`pair rheo `. Unlike typical pair styles, pair rheo ignores the :doc:`special bond ` settings. Instead, -it determines whether to calculate forces based on the status of particles: +it determines whether to calculate forces based on the status of particles: e.g., hydrodynamic forces are only calculated if a fluid particle is involved. ---------- -To model elastic objects, there are current two mechanisms in RHEO, one designed +To model elastic objects, there are currently two mechanisms in RHEO, one designed for bulk solid bodies and the other for thin shells. Both mechanisms rely on -overlaying bonds and therefore require a hybrid of atom style bond and rheo +introducing bonded forces between particles and therefore require a hybrid of atom style bond and rheo (or rheo/thermal). To create an elastic solid body, one has to (a) change the status of constituent