SPH

[ SPH Group Publications ]

Numerical Hydrodynamics

Monash continues to lead the world in the theory of particle methods for the numerical solution of fluid dynamics in astrophysics and geophysical fluid dynamics. Specific applications being investigated at present include star formation, relativistic fluid dynamics; volcanic eruptions and other multi-phase problems; waves breaking on beaches and similar free-surface problems; fracture especially the dynamics of landslides, the calving of icebergs, and the collapse of magma chambers. An extension of this work includes the mathematics of linked swimming bodies.

A simulation of a block falling into water provides a good test of hydrodynamic codes.

Star Formation and Hydrodynamics

The formation of stars is one of the most fundamental processes in the universe without which galaxies and indeed, ourselves would not exist. However our theoretical understanding of star formation is relatively poor, primarily because of the difficulty in modelling the physical process which involves gravity, highly turbulent gas dynamics (at supersonic velocities), magnetic fields, radiation, molecular and dust chemistry. Star formation also involves a truly enormous range in length and time scales which makes simulating the process difficult even with the fastest computers. One of the key aspects of our work here at Monash is to understand the role of magnetic fields in the star formation process, using simulations that form whole star clusters rather than just isolated stars, which gives a much deeper, statistical, picture of star formation that can be compared to real molecular clouds. Much of this work involves developing accurate numerical algorithms for simulating self-gravitating radiation-magnetohydrodynamics over the wide range of length and time scales involved in star formation (which we achieve using the Smoothed Particle Hydrodynamics method). The simulation methods thus developed are readily applicable to other areas of astronomy (and also to many earth-bound problems for which SPH is increasingly being used), amongst which we have or are working on application to the merger of binary neutron star systems; to the nature and statistics of turbulence in molecular clouds; to the role of magnetic fields in galaxies and to warp propagation in accretion discs.

	Snapshot from a calculation of supersonic turbulence in star forming molecular clouds
	Snapshot from a calculation of star cluster formation (see the movies)
	Calculation of warp propagation in an astrophysical accretion disc.