Microfiber motion and web formation in a microchannel heat sink: A numerical approach

A general computer code which solves the motion equations of non-spherical ellipsoidal particles in the fluid flow was developed and fiber motion and web formation at the channel entrance of a microchannel heat sink were investigated numerically. A circular inlet duct, inlet plenum and 15 parallel channels with hydraulic diameter of 225 mu m were considered as the computational domain. Water flow field in the microchannel was solved with Eulerian approach. Fiber motion equations consisting of translational and rotational motions were solved by Lagrangian approach assuming a one-way interaction. The numerical approach was validated for different aspects of the model and close agreement was obtained in comparison with experimental and other numerical data. The objective of the present work is to simulate the formation of fiber web at the entrance of the channels, as well as studying the effects of deposited fibers on the flow field and deposition of next fibers. The results show that, the deposited fibers act as a filter that can lead to deposition of more fibers at the channel entrance. The growth of fiber web in time reported in previous experimental works was also observed in this numerical investigation. (c) 2012 Elsevier Ltd. All rights reserved.