Theoretical investigation of dynamic resistance in pulsatile flow through soft porous space

This study introduces a theoretical model designed to investigate the dynamic resistance encountered by pulsatile cerebrospinal fluid (CSF) flow within the subarachnoid space (SAS), emphasizing its interaction with deformable arachnoid trabeculae (AT). By employing a modified Darcy–Lapwood–Brinkman equation combined with a dynamic Euler–Bernoulli beam model, the transient behavior of CSF flow and AT deformation is analyzed. The study systematically evaluates the effects of AT mechanical properties, SAS permeability, and pulsatile frequency of CSF, highlighting their collective influence on dynamic resistance. Notably, the findings reveal that resistance varies significantly with flow frequency, identifying specific conditions under which porous resistance sharply decreases, thereby facilitating CSF movement through the SAS with minimal impedance. The identification of this frequency-dependent resistance mechanism substantially enhances the current understanding of intracranial fluid dynamics. The proposed model offers new perspectives for utilizing porous media fluid dynamics in diagnostic and therapeutic applications related to brain health.