基于Fourier描述子方法的颗粒形状及曳力模型研究  

Study on Shape and Drag Model of Nonspherical Particles With Fourier Descriptor

作　　者：王锦生[1] 祁海鹰[1] 祝俊宗[1] 

机构地区：[1]清华大学热科学与动力工程教育部重点实验室,北京100084

出　　处：《工程热物理学报》2011年第5期791-794,共4页Journal of Engineering Thermophysics

基　　金：国家自然科学基金重点项目(No.10632070)

摘　　要：如何准确地描述非球形颗粒的形状是研究这类颗粒的普适性曳力模型的关键。本文引入了FD方法,确切地表征了底面为不同形状的正多边形和圆形的柱状颗粒的形状和相互间的差异,建立了用于改进非球形曳力模型适用性的形状阵列。正多边形系列的沉降关系之间的平均差异与FD方法获得的形状差异之间存在着幂函数关系,表明FD方法获得的形状差异能够有效地表征底面形状不同对颗粒终端沉降关系造成的影响。要获得具有普适性的曳力模型,还需以此为基础,进一步引入Ar(或Rep)在不同阶段对沉降关系的影响。Research of the general drag model of non-spherical particles focuses on the shape description.In this paper the Fourier descriptors were introduced as the shape factor.The differences between polygons and circular cylindrical particles were obtained with the Fourier descriptors.A shape diagram was proposed for the general drag model of non-spherical particles.There was a power law relationship between the difference of the settling velocity of polygon series and the difference of the shape with the Fourier descriptors.This indicated that the Fourier descriptors could characterize the effect of base shapes on the settling velocity.Based on this,it was feasible to improve the drag model of non-spherical particles by considering the impact of Ar（or Re_p）.

关 键 词：Fourier描述子 形状参数 非球形颗粒 曳力模型 

分 类 号：TK16[动力工程及工程热物理—热能工程]