THE CREEPING MOTION OF MULTIPLE SPHERICAL LIQUID DROPS

This paper deals with the drag factor of the multiple spherical liquid drops in thecreeping motion by means of the Sampson singularities and collocation technique.The dragfactors of the drops are calculated under distinct conditions:different number of liquiddrops in the chain and different sphere spacing.From the results the influence of theviscosity ratio on the shieding effect and end effect are revealed.The convergence of themethod is also studied in this paper.In this paper the collocation technique developed by Gluckman etal.in treatingthe rigid sphere case is applied to deal with the creeping motion of multiplespherical liquid drops which has important applications in bioengineering andchemical engineering.Writing the general solutions in inner and outer regions ofthe spheres and satisfying the kinematic and dynamic matching conditions at thecollocation points on the interfaces,a set of linear algebraic equations is obtainedto determine the unknown coefficients in the solutions.By means of any ma     

血液入口段两相流动的层流NS方程数值模拟

本文采用球形刚性颗粒悬浮于牛顿流体的血液模型，基于有相间滑移的两相流动层流Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ方程，采用相间滑移算法（Ｉｎｔｅｒ－ＰｈａｓｅＳｌｉｐＡｌｇｏｒｉｔｈｍ）对圆管内定常轴对称血液入口两相流动问题进行了计算，获得了与实验结果吻合的计算结果，较好地模拟血液流动中红细胞的径向迁移现象，结果表明，采用二相流动模型研究血液流动是一种有前途的方法。     

多个球形液滴的蠕动流

本文利用Sampson奇点及配置法求解多个球形液滴在蠕动流中的阻力系数.计算了由不同数目液滴组成的液滴串在不同液滴间距下的阻力系数并揭示了粘度比对遮蔽效应和端缘效应的影响.文章还对方法的收敛性进行了研究.     

The creeping motion of multiple spherical liquid drops

This paper deals with the drag factor of the multiple spherical liquid drops in the creeping motion by means of the Sampson singularities and collocation technique. The drag factors of the drops are calculated under distinct conditions: different number of liquid drops in the chain and different sphere spacing. From the results the influence of the viscosity ratio on the shielding effect and end effect are revealed. The convergence of the method is also studied in this paper.In this paper the collocation technique developed by Gluckman et al. in treating the rigid sphere case is applied to deal with the creeping motion of multiple spherical liquid drops which has improtant applications in bioengineering and chemical engineering. Writing the general solutions in inner and outer regions of the spheres and satisfying the kinematic and dynamic matching conditions at the collocation points on the interfaces, a set of linear algebraic equations is obtained to determine the unknown coefficients in the solutions. By means of any matrix inversion technique the approximate solutions are presented. In the first section of this paper the mathematic formulation of the problem is given and then in the second section the numerical results are introduced and analysed.     

仿生多孔翼型后缘自噪声数值研究

采用大涡模拟(LES)和声比拟(AA)结合的方法，在低马赫数条件下，对SD7003多孔翼型自噪声声场进行计算，研究多孔材料在不同来流迎角下对翼型自噪声远场声压的影响规律，并阐述噪声的影响机理。结果表明：LES与AA相结合的方法能够较为准确地计算多孔翼型的边界层特征以及远场声压，且数值模拟结果与实验结果非常吻合。来流迎角为0°时，多孔翼型整体声压级随着渗透率的减小先减小后增大，渗透率为5×10^-11 m²时多孔材料的降噪效果最佳。多孔翼型整体声压级随着迎角的增大而增大，但多孔材料的降噪效果随着迎角的增大而减小。多孔材料的存在能够有效地削弱翼型表面的大尺度相干结构，使得翼型表面的RMS压强脉动峰值减小，从而抑制翼型远场噪声。     

可渗透壁对翼型声涡相互作用下流场及声场的影响

由仿生学原理构建的可渗透翼型对湍流气动噪声抑制作用已展现良好的应用前景。对NACA 0012可渗透翼型和实体翼型进行了数值计算，得到了声涡相互作用下气动噪声声场和流场，分析了可渗透壁对翼型流场和声场的影响。研究表明，相对实体翼型，可渗透壁通过减小声源强度降低了主纯音噪声声压级幅值和远场总声压级，消除了高阶离散纯音，但对噪声的指向性没有较大改变。进一步的流场分析表明，可渗透壁对翼型气动性能影响不大的情况下能够降低边界层扰动和翼型后缘大尺度涡旋强度，并推迟分离泡转捩和再附位置。