Symmetry reduction for molecular dynamics simulation of an imploding gas bubble

Molecular Dynamics of Extreme Mass Segregation in a Rapidly Collapsing Bubble

“…In this paper we study molecular dynamics (for detailed description of our model see refs. [17,18]) under conditions where the most extreme temperatures and densities can be expected inside an imploding bubble. Figure 1, for instance, shows the radius R as a function of time t for bubbles which exhibit the largest expansion ratio (∼30) of maximum radius to ambient radius yet measured.…”

“…The number of atoms in such a real bubble is about 8 × 10 8 , which exceeds standard computational capabilities. To make the calculations feasible we assume spherical symmetry and simulate gas inside a cone [18] with a vertex half angle of 0.8 • , which therefore contains about 55,000 atoms. Some cases were verified for cone angles of 1.6 • where the number of atoms is roughly 4 times greater.…”

Effects of Gas Dynamics on Rapidly Collapsing Bubbles

“…This section will outline the results of various simulations in an attempt to give an understanding of how various features affect the evolution of the MD system. Previous works have considered the effects of various modeling choices affect the gas inside of the bubble [8][9][10]19].…”

“…The algorithm presented below consists of a modified version of that found in [8,9]. The same efficient, event driven algorithm with spatial partitioning as [18] and supplemented with conical symmetry reduction [19] to integrate the particle system. All simulation results presented here use a cone angle of 15 degrees, which was chosen based on Bass et al [19] to give dependable results while drastically reducing the number of particles being simulated.…”

“…The same efficient, event driven algorithm with spatial partitioning as [18] and supplemented with conical symmetry reduction [19] to integrate the particle system. All simulation results presented here use a cone angle of 15 degrees, which was chosen based on Bass et al [19] to give dependable results while drastically reducing the number of particles being simulated. Using these methods and making some improvements, a system of a million particles can be fully collapsed within 24 hours, though this depends heavily on the composition and conditions it is subjected to.…”