动态粒子组成的椭球体的几何尺寸计算方法

为了研究一种线状高分子材料在另一种高分子基体中熔融断裂后，从椭球变化到球的过程，本文给出了由动态粒子堆积成的密度有涨落椭球体的几何尺寸计算方法，介绍了内坐标与回转半径张量法“扭正”椭球、在椭球体边界上取点、非线性最小二乘法拟合椭球方程三个方面的具体计算方法。本文提出了用27个格子确定边界点的方法。在用耗散粒子动力学模拟椭球体变化到球体的过程中，本文用上述计算方法正确测量了椭球体三个半轴的变化，并用不同密度的体系所得体积值较稳定验证了计算方法的准确性。

Geometry computation of ellipsoidal drop constructed by dynamic particles

When heating up a polymer as an extended thread embedded in another immiscible polymer matrix the thread will break up,become ellipsoidal drops,and further retract to be sphere shape.Such phenomenon has received much attention in recent years.In thepresent study,inertial tension calculation in coordinate transition,setting up the way of determination of the ellipsoidal surface,andnonlinear least square fitting ellipsoid equation were reported.The article presents a method of 27-cell locating the boundary point.Inthe simulation of ellipsoidal drop retraction using dissipative particle dynamics(DPD),the right dimension of ellipsoid was gotten usingthe said computation method,the conserve ellipsoid volume of different density system shows the method is accurate.