Session: 07-08-04: Computational Modeling in Biomedical Applications

Paper Number: 190772

Three-Dimensional Fluid-Structure Interaction Modelling of Biomechanical Response in an Idealised Five-Lobe Human Lung During Sinusoinal Ventilation-Student Project-Part 1 

Understanding the mechanical behaviour of the human lung under dynamic breathing conditions is critical for both biomedical research and the development of clinical interventions. The lung exhibits complex interactions between airflow and compliant tissue, which necessitate computational approaches that capture the coupled fluid–structure dynamics. In this study, we present a three-dimensional fluid–structure interaction (FSI) model of an idealised five-lobe human lung subjected to sinusoidal ventilation, with the aim of characterising regional airflow distribution, parenchymal deformation, and stress patterns under physiologically relevant conditions.

The idealised lung geometry was constructed to represent all five anatomical lobes, providing a simplified yet anatomically informed framework for computational analysis. The fluid domain simulates air inhalation and exhalation driven by a sinusoidal pressure waveform, representing normal tidal breathing. The structural domain models the lung parenchyma as a linear elastic material, accounting for tissue compliance and enabling dynamic deformation in response to the internal fluid forces. A partitioned FSI approach was employed, coupling computational fluid dynamics (CFD) and finite element structural analysis at each time step to ensure accurate interaction between airflow and tissue mechanics.

Simulation results demonstrate significant heterogeneity in airflow distribution across the lobes, with peak flow rates and pressure gradients occurring during maximum inspiration. Coupled FSI modelling reveals that parenchymal deformation is non-uniform, with higher tissue strains observed in lower lobes due to geometric asymmetry and gravitational effects. The sinusoidal ventilation induced cyclic stress and displacement patterns, highlighting phase-dependent biomechanical responses that would not be captured by uncoupled fluid or structural models alone. Notably, regions of elevated stress correspond to areas with concentrated airflow, suggesting that ventilation-induced mechanical loading may contribute to localised tissue strain and potential injury under pathological conditions or high-intensity mechanical ventilation.

This study demonstrates the applicability of three-dimensional FSI modelling in idealised multi-lobe lung geometries, providing a computationally efficient platform to investigate biomechanical responses under cyclic ventilation. The findings provide insight into the interplay between airflow and tissue mechanics, which is essential for understanding regional lung function, ventilation heterogeneity, and potential sites of mechanical stress accumulation. Moreover, the proposed framework can serve as a basis for future research on pathological lung conditions, optimisation of mechanical ventilation strategies, and the development of reduced-order models for educational and translational applications.

Overall, the study highlights the importance of multiphysics coupling in accurately representing pulmonary biomechanics, emphasising that idealised lung models, when coupled with FSI analysis, can provide meaningful insights into both fundamental lung function and the mechanical factors influencing tissue integrity.

Presenting Author: Sherif Ashaat Institute of Applied Technology

Presenting Author Biography: Sherif is an assistant professor

Authors:

Tung Vuong Manukau Institute of Technology
Sherif Ashaat Institute of Applied Technology