1. APNe Conference, Seattle, July 2003 Clumpy Flows in Protoplanetary and Planetary Nebulae Alexei Poludnenko, Adam Frank University of Rochester, Laboratory for Laser Energetics Sorin Mitran University of North Carolina University of Rochester Laboratory for Laser Energetics

2. APNe Conference, Seattle, July 2003 AstroBEAR Code and BEARCLAW package BEARCLAW features:  Unified code for computations in 1- 4 dimensions  Automatic adaptive mesh refinement with flexible refinement parameters and scenarios  Multi-physics capability  Possibility of multiple subdomains of the computational domain with: different dimensionality, refinement scenarios, numerical schemes and/or Riemann solvers employed different sets of PDEs solved on each one  A variety of output formats (AMRCLAW, TECPLOT, HDF, etc.) AstroBEAR features:  Computations in 2D, 2.5D, and 3D and access to all features without coding or recompilation  Set of different Riemann solvers (full non-linear hydrodynamic, linearized Roe, linearized MHD)  Generic implicit 4-th order accurate source term routine suited for arbitrary systems of source term ODEs  Modular structure for user-supplied applications and a variety of provided initial conditions Current AstroBEAR development:  Full ionization dynamics and photoionization  MHD  Radiation driving via Sobolev approximation (e.g. radiatively driven disk outflows)  MPI- and OpenMP- (SGI) based parallelization with full “knapsack-algorithm” load balancing  Fast Multipole Method for elliptic equations  Embedded boundaries for complicated flow geomtries AstroBEAR results website: http://pas.rochester.edu/~wma

3. APNe Conference, Seattle, July 2003 CRL 618 Susan R. Trammell (UNC Charlotte) et al.

4. APNe Conference, Seattle, July 2003 Interacting regime of clump evolution: d = 0.95 d crit Non-interacting regime of clump evolution: d = 2.98 d crit

5. APNe Conference, Seattle, July 2003 Qualitative characteristics of adiabatic inhomogeneous systems:  thickness of the clump system as opposed to the total clump mass  clump distribution in the system as opposed to the total number of clumps Quantitative characteristics of the adiabatic clumpy systems:  Critical density, critical separation between clump centers normal to the flow:  Clump destruction length L CD, distance traveled by a clump prior to its breakup Those two parameters allow one to distinguish between interacting and noninteracting regimes of clump system evolution Poludnenko, A.Y., Frank, A., Blackman, E.G. 2002, ApJ, 576, 832

6. APNe Conference, Seattle, July 2003 Radiative Hypersonic Cosmic Bullets  An example of a radiatively cooled inhomogeneous environment  Systems are practically always in the noninteracting regime, i.e. there is no lateral expansion and merging  The main process is clump fragmentation via instabilities  The properties of the global flow determine the initial spectrum of fragments that are formed  The details of clump distribution determine the final spectrum of fragments  The final spectrum of fragments determines the structure and properties of the resulting system Mach 20 radiatively cooled bullet, ambient density 10 2 cc -1, clump density 10 4, t cool /t hydro = 2.8*10 -3

7. APNe Conference, Seattle, July 2003 Mach 10 radiatively cooled bullet, ambient density 10 3 cc -1, clump density 10 5, t cool /t hydro = 2.5*10 -2 Mach 10 radiatively cooled bullet, ambient density 10 2 cc -1, clump density 10 4 cc -1, t cool /t hydro = 0.25

8. APNe Conference, Seattle, July 2003 Mach 20 radiatively cooled bullet, ambient density 10 3 cc -1, clump density 10 5, t = 204 yrs., t cool /t hydro = 2.8*10 -5

9. APNe Conference, Seattle, July 2003 Mach 200 radiatively cooled bullet, ambient density 10 2 cc -1, clump density 10 4, t = 18.3 yrs., t cool /t hydro = 3.7

10. APNe Conference, Seattle, July 2003