Abstract:
Flow behavior in bifurcation models is of great importance to health risk assessments and pulmonary drug delivery. This is particularly true of secondary flow behavior in multi-bifurcation models. Previously, both numerical and experimental methods have shown that four-vortex secondary flow structures can develop in the cross-sections of grand-daughter branches. This work shows that the development of secondary flow in the grand-daughter tubes is due to local stretching of vortex lines in the upstream DT. Scaling arguments have been used to derive two critical parameters governing this particular vorticity transport problem. A simple model for vorticity generation and transport is proposed, taking into account the geometric limitations imposed by the rigid walls of the tubes.
