melt_IBM

This is a repository for a DNS code which simulates the Lagrangian melting of a solid object. The journal paper detailing this work is found at:

• Zhong, K., Howland, C. J., Lohse, D., and Verzicco, R. (2025). A front-tracking immersed-boundary framework for simulating Lagrangian melting problems. J. Comput. Phys., page 113762.

There is also a WIP documentation for this repository found here.

Dependencies

• MPI Fortran compiler
• HDF5
• FFTW3
• LAPACK, BLAS, etc

Fortran compiler can be GNU (gfortran) or Intel, but it is important that the HDF5 library was compiled using the specified Fortran compiler.

For MacOS, dependendices can be installed simply:

brew install fftw hdf5-mpi open-mpi openblas lapack gcc

Usage

Simulation parameters are specified in bou.in and part.in. HIT parameters specified in HITForcing.in.

Key features

• Incompressible Navier--Stokes + temperature equation, with optional coupling through thermal Boussinesq driving
• Second-order staggered, finite difference + low-storage RK3 substepping
• Moving-least-squares immersed boundary method treatment: immersed solid is a triangulated surface, which is read-in as a .gts file
• Fluid-solid interaction governed by Newton--Euler equations
• Melting governed by the Stefan condition
• Triangulated solid geometry is dynamically remeshed as it melts
• MPI parallelisation is the slab decomposition

Main restrictions

• Single solid object (no collision treatment)
• Periodic domain
• Matched thermal diffusivities between solid and liquid phases
• Matched densities between the phases