Simulation of deformation and flow of pulmonary acinus using morphing compared with self-similar deformation

Abstract

In previous studies of the flow inside the pulmonary acinus, the deformation of acinus was limited because a relatively simple deformation methods, such as self-similar deformation, is used. However, acinus deformation may be complex and heterogeneous. The purpose of this study is to evaluate the influence of the difference in wall deformation between the morphed model and the self-similar deformation model on flow field. The heterogeneous deformation achieved in this study is more actual by using the morphing technology that continuously changes from one shape to another. STAR-CCM + Ver. 13.06 (Siemens PLM Software) was used for numerical calculation, and the governing equations of working fluid are continuous equations and Navier–Stokes equations (NS equations). As a result, the differences in deformation influenced the formation of streamlines at the distal end of the alveolar regions. In the self-similar deformation model, the flow does not change throughout a cycle, whereas in the morphed model, the flow changes during a cycle. Graphic abstract