AMRA: Examples

Examples

References: Woodward, P.R., Colella, P., 1984, JCP, 54, 115


Problem

	All zones are plotted in the case of `AMR`; original postscript files are also available (ppm 6.45M, amr 1.65M). `PPM` (t=0.038) `AMR` (t=0.038) The movie presents temporal evolution of density and velocity on 5 levels of grids with frames taken each 5 time steps. `AMR` evolution (1.09M)



truncation error/resolution
10^-1	10^-2	10^-3	10^-4	6400
2.7 M	2.7 M	2.8 M	3.0 M	2.6 M

References: Plewa, T., 1995, MNRAS, 275, 143

Problem

	The evolution of compact supernova remnant (cSNR) is one of the most challenging problems of astrophysical hydrodynamics due to fact that the cooling time scale becomes much shorter than the dynamical time scale as the remnant enters its radiative phase of evolution. The cooled material condensates very rapidly and the thin shell forms behind the forward shock. At the end of this simulation density of the thin shell is nearly 4 orders of magnitude higher than the density of ambient gas. Another consequence of the catastrophic cooling is the formation of secondary shocks which modify the flow pattern near the shell. The cSNRs are one of the most luminuous objects in the Universe with peak luminosities reaching 10⁺⁴³ erg/s.

References: Hawley, J.F., Zabusky, N.J., 1989, Phys. Rev. Let., 63, 1241

Problem

	Initially Mach 1.2 shock is positioned at x=5 and contact discontinuity touches y=0 at x=15. The density jump across discontinuity is equal to 3 and its inclination is equal to 30 degrees. The gas is ideal and gamma=1.4. The evolution starts at t=0 and is followed up to t=620 inside the computational domain of size 62x372. Lower and upper boundaries are reflecting; at the left-hand boundary we imposed fixed inflow with the state set equal to post-shock values and the right-hand boundary is transmitting.



	truncation error/resolution
	10^-1	10^-2	10^-3	960x160
density	0.6 M	0.6 M	0.6 M	0.6 M
fluid tracer	0.5 M	0.5 M	0.5 M	0.5 M
schlieren-type	0.8 M	0.7 M	0.7 M	0.8 M
grid levels	0.8 M	0.7 M	0.7 M

References: Müller, E., Fryxell, B., Arnett, D., 1991, A&A, 251, 505

Problem

	We consider evolution of strongly perturbed supernova in two dimensions assuming spherical symmetry. We start 300 s after the core bounce and continue calculations to t=13000 s. Development of Rayleigh-Taylor instabilities and subsequent large-scale mixing is observed and believed as being responsible for some spectral features of SN 1987A and most probably common for other Type-II supernovae.

References: Kritsuk, A., Plewa, T., Müller, E., 2000, astro-ph/0008017

Problem

	We use hydrodynamic simulations with adaptive grid refinement to study the dependence of hot gas flows in X-ray luminous giant elliptical galaxies on the efficiency of heat supply to the gas. We consider a number of potential heating mechanisms including Type Ia supernovae and sporadic nuclear activity of a central supermassive black hole. As a starting point for this research we use an equilibrium hydrostatic recycling model (Kritsuk 1996). We show that a compact cooling inflow develops, if the heating is slightly insufficient to counterbalance radiative cooling of the hot gas in the central few kiloparsecs. An excessive heating in the centre, instead, drives a convectively unstable outflow. We model the onset of the instability and a quasi-steady convective regime in the core of the galaxy in two-dimensions assuming axial symmetry. Provided the power of net energy supply in the core is not too high, the convection remains subsonic. The convective pattern is dominated by buoyancy driven large-scale mushroom-like structures. Unlike in the case of a cooling inflow, the X-ray surface brightness of an (on average) isentropic convective core does not display a sharp maximum at the centre. A hybrid model, which combines a subsonic peripheral cooling inflow with an inner convective core, appears to be stable. We also discuss observational implications of these results.

Results

	Hydrodynamics of galactic cooling flows web page with lots of computer generated movies and still pictures.

References: Ciecielag, P., Plewa, T., Rózyczka, M., 2000, Astron. Nachr., 321, 171

Problem

	A problem of mass flow in the immediate vicinity of a planet embedded in a protoplanetary disk is studied numerically in two dimensions. Large differences in temporal and spatial scales involved suggest that a specialized discretization method for solution of hydrodynamical equations may offer great savings in computational resources, and can make extensive parameter studies feasible. Preliminary results obtained with help of Adaptive Mesh Refinement technique and high-order explicit Eulerian solver are presented. This combination of numerical techniques appears to be an excellent tool which allows for direct simulations of mass flow in vicinity of the accretor at moderate computational cost. The present communication is focused on the structure of the outer part of the circumplanetary disk. We employ the multifluid option to the hydrodynamical solver to prove that the circumplanetary disk is composed of the gas transfered into it from the edges of the gap.

Results

	AVS visualization

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