CFD model for a 3-D inhaling mannequin: verification and validation

Area of Science:

• Fluid dynamics
• Particle transport modeling
• Occupational health simulations

Background:

• Accurate modeling of airflow and particle transport is crucial for understanding inhalation exposure in occupational settings.
• Computational fluid dynamics (CFD) offers a powerful tool for simulating complex airflow patterns within anatomical models.

Purpose of the Study:

• To investigate the application of CFD for modeling airflow and particle transport in an inhaling anatomical mannequin.
• To verify and validate the CFD simulation methods, assessing convergence and model uncertainties.
• To compare simulated particle aspiration fractions with experimental data under occupational and resting breathing conditions.

Main Methods:

• Utilized computational fluid dynamics (CFD) to simulate air flow and particle transport.
• Employed the standard k-epsilon turbulence model for flow field analysis.
• Performed laminar particle trajectory studies to determine aspiration fractions.
• Verified and validated simulation results against experimental data.

Main Results:

• The k-epsilon model yielded a reasonable flow field, but vertical velocity components were underestimated compared to experimental data.
• Truncation of the computational model at hip height contributed to the vertical velocity discrepancies.
• Particle aspiration fractions shifted towards smaller particles in simulations, consistent with the observed velocity field differences.

Conclusions:

• CFD modeling, using the k-epsilon model, provides a viable approach for simulating airflow in anatomical mannequins.
• Model limitations, such as computational domain truncation, can influence simulation accuracy, particularly for vertical velocity components.
• The study highlights the need for careful validation and consideration of model uncertainties when interpreting particle aspiration fractions from CFD simulations.