The following links point to a few open-source solvers developed in CRUNCH and elsewhere:
 NEKTAR is the open-source parallel continuum-based solver based on the spectral/hp element spatial discretization, and has been under constant development at CRUNCH since the 90s. The solution in each spectral element is approximated in terms of hierarchical mixed order Jacobi polynomial expansions. NEKTAR employs a third-order accurate semi-implicit time integration scheme, while the iterative solution of linear systems is performed with the Preconditioned Conjugate Gradient method using an effective and scalable low-energy basis preconditioner. A sub-iteration algorithm based on fixed-point iterations is performed on the nonlinear term complemented with Aitken relaxation at each sub-iteration to increase stability of the scheme in fluid-structure (FSI) simulations. Moreover, the structure solver is based on a recently developed generalized fictitious damping method that enables the stable resolution of cases in which low mass ratios (as in the case of blood ow through arteries) lead to very large structural displacements. The available source code solves unsteady incompressible Navier-Stokes equations and may be used for academic purposes only. |
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 Nektar++ is a spectral/hp element framework designed to support the construction of efficient high-performance scalable solvers for a wide range of partial differential equations. NEKTAR++ is expanded upon the core libraries of NEKTAR by one of the first developers, Prof. Sherwin at Imperial College London, and has become a very efficient and strong tool for solving partial differential equations. |
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 ParaView is one of the powerful open-source multi-platform data analysis and visualization application. ParaView was developed to analyze extremely large datasets using distributed memory computing resources. It can be run on supercomputers to analyze datasets of petascale size as well as on laptops for smaller data. NEKTAR Plugin for ParaView, has been developed in collaboration with the team at Argonne National Laboratory, is an addon for large-scale parallel visualization of the output binary files from NEKTAR without the need to convert them into .vtu data files. Note that the plugin source code has to be built after ParaView source code is compiled and built. The plugin will be officially released within the ParaView source code in the near future. |
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 LAMMPS is a classical molecular dynamics code and a highly parallel and efficient platform for numerical schemes that target solid-state materials (metals, semiconductors), soft matter (biomolecules, polymers) and coarse-grained or mesoscopic systems. It can be used to model atoms or, more generically, as a parallel particle simulator at the atomic, meso, or continuum scale, and is designed to be easily modified or extended with a new functionality. USER-MESO is our open-source DPD package that is developed by the CRUNCH DPD Club members using LAMMPS platform. This package includes the many-body DPD (mDPD) model for multiphase problems, the energy-conserving DPD (eDPD) model for nonisothermal hydrodynamics, and the transport DPD (tDPD) model for mesoscopic problems involving advection-diffusion-reaction processes. USER-MESO along with LAMMPS code can be downloaded directly at LAMMPS website. Documentation for the USER-MESO package is available here. User-defined modules have also been developed besides the DPD base solvers for a number of specific applications (e.g., for cell mechanics and wall boundary condition treatments). |
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 Multiscale Universal Interface (MUI) is a lightweight plugin library that can couple various solvers that are described in Lagrangian, Eulerian or the combination of both frameworks and use particles or grids. MUI provides services enabling the communication and interpretation of arbitrary physical quantities using arbitrary data types as demanded by each participating solver for users to implement their own coupling algorithm in an efficient way. MUI was originally developed by Dr. Yuhang Tang and We have successfully implemented a concurrent multiscale coupling of NEKTAR and LAMMPS using MUI, where we are able to perform time-scale bridging for very long and slow processes or spatial coupling of continuum-atomistic domains. |
