Study on Dynamical Evolution of Dense Stellar Systems with Special Purpose Computers.

1991学年。Makino访问了爱丁堡大学，并与Heggie、McMillan和Aarseth博士(剑桥大学)合作，为专用计算机GRAPE开发了用于模拟的Hermite集成代码。该程序比Aarseth程序更简单，更适用于GRPE，Aarseth程序被广泛应用于碰撞引力系统的N体模拟中。McMillan博士访问了东京大学，并与稻垣博士合作实现了他的星团到GRPE-2A的模拟程序。Hunquist博士还访问了东京大学，并在GRPE-2A上实现了他的SPH代码。1992学年，Makino、Hut和Hunquist博士系统地研究了用于无碰撞引力系统的树编码中的错误。他们发现，树编码提供了足够高的精度来进行引力N体模拟。Hachisu博士开发了一种涡旋动力…更多不可压缩流体模拟的MICS代码。他发现GRPE系统可以极大地加速涡旋动力学模拟和引力N体模拟。1993学年，我们在东京大学小叶校区举办了一个关于密集恒星系统的动力学演化和专用计算机开发的研讨会，总结了三年的合作成果。我们的结论是，恒星的直接碰撞在致密恒星系统中起着重要作用。Hachisu、Ueno和Miyama博士研究了各种类型的计算流体力学程序，并得出结论：Gudnov型SPH方法最适合于模拟自引力流体的专用计算机。SPH专用计算机的概念和详细设计是由东京大学和国家天文台合作完成的。在1994学年，我们将制作SPH机的测试板，并开始开发SPH码的专用LSI。较少

Academic Year 1991Dr. Makino visited University of Edinburgh and developed a Hermite integration code for the simulations with the special purpose computer, GRAPE, in collaboration with Drs. Heggie, McMillan, and Aarseth (Cambridge University). This code is simpler and more suitable to GRAPE than the Aarseth code, which has been widely used in the N-body simulations of collisional gravitational systems.Dr.McMillan visited University of Tokyo and implemented his simulation code for stellar cluster to GRAPE-2A in collaboration with Dr.Inagaki. Dr.Hunquist also visited in University of Tokyo and implemented his SPH code to GRAPE-2A. They confirmed that GRAPE systems are suitable to the use of both two codes.Academic Year 1992Drs.Makino, Hut, and Hunquist systematically investigated the error in the tree code, which is used in collisionless gravitational systems. They found the tree code offers an accuracy high enough for gravitational N-body simulations. Dr.Hachisu developed a vortex dyna … More mics code of incompressible fluid simulations. He found that GRAPE systems can greatly accelerate the vortex dynamics simulations as well as gravitational N-body simulations.Academic Year 1993We held a workshop on the dynamical evolution of dense stellar systems and the development of special purpose computers to summarize the results of three-years collaborations in Komaba campus University of Tokyo. We concluded that the direct collision of stars plays an important role in dense stellar systems. Drs.Hachisu, Ueno, and Miyama investigated the various types of computational fluid dynamics codes and concluded that the Gudnov type SPH method is most suitable to the special purpose computers for the simulations of self-gravitational fluid. The conceptual and detailed designs of the special purpose computer for SPH were done in collaboration of University of Tokyo and National Astronomical Observatory. In the academic year 1994, we shall make a test board of SPH machine and start to develop a special purpose LSI for the SPH code. Less