Particle transport modeling in pulmonary airways with high-order elements

Area of Science:

• Computational fluid dynamics
• Particle transport and deposition modeling
• Biomedical engineering

Background:

• Inhaled particles pose risks (e.g., viruses) or offer benefits (e.g., drug delivery).
• Simulating particle transport and deposition is computationally challenging due to coupled Navier-Stokes and advection-diffusion equations.
• Resolving multiple length scales is crucial as the advection-to-diffusion ratio varies across particle sizes.

Purpose of the Study:

• To evaluate the spectral element method for simulating inhaled particle transport and deposition.
• To assess the method's efficiency and accuracy in resolving multiple length scales in airway geometries.
• To validate simulation results against experimental data for particle deposition.

Main Methods:

• The spectral element method was employed to solve coupled Navier-Stokes and advection-diffusion equations.
• Simulations utilized human (Weibel model A) and rat airway geometries.
• Particles ranging from 1 to 100 nm were simulated using basis polynomials of order 5 to 11.

Main Results:

• Higher-order spectral elements accurately captured short wavelengths in advection-diffusion solutions.
• The method demonstrated efficiency for the computationally intensive Navier-Stokes solution.
• Advantages of spectral elements became evident for larger particles (smaller diffusion coefficients).

Conclusions:

• The spectral element method is a computationally efficient and accurate approach for simulating inhaled particle transport and deposition.
• This method effectively handles the multi-scale physics involved in particle dynamics within airways.
• The findings support the use of spectral elements for detailed airway particle deposition analysis.