Examining mesh independence for flow dynamics in the human nasal cavity

Area of Science:

• Computational fluid dynamics (CFD) applied to respiratory system modeling.
• Biomedical engineering and simulation.
• Meshing strategies for complex geometries.

Background:

• Computational resources enable sophisticated respiratory modeling.
• Increasing mesh element counts in recent publications.
• Complex geometries like the nasal cavity present flow challenges.

Purpose of the Study:

• To develop a robust method for evaluating near-wall mesh resolution in respiratory modeling.
• To assess the suitability of non-dimensional wall unit y+ for laminar flow mesh evaluation.
• To propose an improved mesh comparison technique beyond single line profiles.

Main Methods:

• Utilized non-dimensional wall unit y+ for near-wall mesh evaluation in laminar flow.
• Performed mesh independence analysis using line profiles.
• Developed a 2D cross-sectional plane subtraction method with interpolated scalar values.
• Extended the subtraction method to 3D volume subtraction.

Main Results:

• Line profile location significantly influenced mesh independence results.
• Single line profiles are insufficient for whole-field mesh convergence assessment.
• Refined near-wall meshes reduced reliance on overall mesh size in narrow passages.
• Wider passages showed velocity sensitivity to mesh size, necessitating refinement.

Conclusions:

• A novel 2D/3D interpolated subtraction method offers improved mesh evaluation for respiratory models.
• Near-wall mesh refinement is crucial, particularly in complex and wider flow passages.
• This method enhances the reliability of CFD simulations in respiratory research.