CAJ | 학술논문

波江座α是一颗具有代表性并被比较充分观测的快速自转恒星.以该星为例,建立了一种可以利用有限的观测数据有效反演此类恒星椭球形状及其内部结构的并行数值方法.求解此问题的经典近似方法(一般)只对慢速旋转的恒星有效,需要对旋转角速度作小扰动假设;而该方法为严格数值求解恒星的旋转多方球模型,对快速旋转的情形仍然保持有效.该方法采用的大规模并行有限元方法,对超级计算设备的性能与计算方法实现的效率都有很高的需求.计算表明,如果有限元网格包含数千万单元水平,则经过充分内存优化的代码在上海超级计算中心曙光5000A 超级计算机上运行需要不少于1024核的资源.
파강좌α시일과구유대표성병피비교충분관측적쾌속자전항성.이해성위례,건립료일충가이이용유한적관측수거유효반연차류항성타구형상급기내부결구적병행수치방법.구해차문제적경전근사방법(일반)지대만속선전적항성유효,수요대선전각속도작소우동가설;이해방법위엄격수치구해항성적선전다방구모형,대쾌속선전적정형잉연보지유효.해방법채용적대규모병행유한원방법,대초급계산설비적성능여계산방법실현적효솔도유흔고적수구.계산표명,여과유한원망격포함수천만단원수평,칙경과충분내존우화적대마재상해초급계산중심서광5000A 초급계산궤상운행수요불소우1024핵적자원.
We present a three-dimensional numerical method for calculating the non-spherical shape and internal structure of a model of a rapidly rotating gaseous body with a polytropic index unity. The calculation is based on a finite element method and accounts for the full effects of rotation. We apply it to a model of a rapidly rotating, highly flattened star (α Eridani). The distributions of density and pressure are determined via a hybrid inverse approach by adjusting a priori unknown coe?cient in the equation of state (EOS) until the model mass matches the observed mass of the star. The numerical method, implemented as a 3D finite element scheme, relies on massively parallel computing facilities. On the Dawning 5000A machine in Shanghai Supercomputer Center (SSC), we utilized typically 1024 cores to carry out our calculations effectively. The model and numerical method are both ready to be generalized to include various physical features and processes such as differential rotation, tidal effects and more realistic EOS of gaseous configurations.