CAJ | 학술논문

流场运动趋势一直是科学研究的热点和难点，而时变流场的有限时间李雅普诺夫指数(Finite-Time Lyapunov Exponent，FTLE)能够度量流体质点运动轨迹伸展程度，反映一段时间内质点的汇聚和分离情况，对其可视化可用来分析流体质点的运动趋势，同时良好的体现流场的拉格朗日拓扑结构(LCS)。本文针对离散流场中质点 FTLE计算量大的特点，通过均匀划分流场数据网格，实现每个处理器负责读取其划分网格区域内的每个时间步的流场数据，并计算所负责网格区域内流体质点的轨迹线积分，积分结束后并行计算划分网格区域内质点的 FTLE。利用上述思想实现了 MPI并行编程环境下的一种基于轨迹线积分的流场 FTLE并行计算方法。
류장운동추세일직시과학연구적열점화난점，이시변류장적유한시간리아보낙부지수(Finite-Time Lyapunov Exponent，FTLE)능구도량류체질점운동궤적신전정도，반영일단시간내질점적회취화분리정황，대기가시화가용래분석류체질점적운동추세，동시량호적체현류장적랍격랑일탁복결구(LCS)。본문침대리산류장중질점 FTLE계산량대적특점，통과균균화분류장수거망격，실현매개처리기부책독취기화분망격구역내적매개시간보적류장수거，병계산소부책망격구역내류체질점적궤적선적분，적분결속후병행계산화분망격구역내질점적 FTLE。이용상술사상실현료 MPI병행편정배경하적일충기우궤적선적분적류장 FTLE병행계산방법。
Flow field has becomea widely used, in-depth research direction, and the tendency of its particles is still difficult and is a hot spot of research. The Finite-Time Lyapunov Exponent (FTLE) is a scalar to measure the degree of fluid particle trajectory stretching, and the visualization of FTLE can well reflect the Lagrange topology (LCS) of the flow field. So FTLE calculation method has become one of the hot research contents, as well. According to the characteristics of the time-varying flow field dataset, the FTLE computation of Time-Varying Flow Fields is related with substantial particles. This paper implements a FTLE flow field parallel calculation method by MPI based on pathline integrals.