Separation flow through asymmetric periodic tubes

Abstract

A systematic study of the impact of geometrical factors on separation flow characteristics within a longitudinally asymmetric but axially symmetric infinite periodic tube is presented throughout the main body of the paper. To disambiguate the inception of flow separation zones concerning the various geometrical aspects, we have undertaken a numerical study. The boundary integral technique is used for a periodic tube with an infinite number of wavesections to obtain the solution of the Stokes equation. For some amplitudes, we show that separation zones can be formed inside the enlarged areas of the tube. The first separation zone appears beyond a certain profile amplitude whereas the second separation zone is produced after the first separation zone at a larger amplitude. Also, the volume of the separation zone is discussed which has great physical importance, for example, it can be used in the particle separation process. The volume of the first separation zone is directly dependent on the amplitude of the tube profile. In this case, the volume increases as the tube amplitude increases.

Keywords

• Axisymmetric Stokes flow
• Separation zone
• Asymmetric periodic tube
• Microfluidics
• Boundary integral technique
• Geometric effect