engleski

OPEN-SOURCE CFD ANALYSIS OF NASAL FLOWS

Abstract.Recently, as studying the transmission of airborne particles and the effect of filtration devicesbecame of pronounced importance due to the COVID-19 pandemic, having the ability to visualise nasalflows and perform numerical analyses may prove to be an invaluable resource. What is more, due to thecomplexity of the anatomy of the nasal cavity and its variations in patients, a patient-specific analysiscould help in treating different conditions affecting nasal flows. That is why this research describes ademocratised and easily reproducible procedure used as a tool for the investigation of nasal flows usingopen-source computational fluid dynamics.A detailed overview of a procedure developed for analysis of nasal flows is presented. Every step ofthe procedure, from creating the computational model to airflow simulation, is based on freely avail-able and open-source tools, thus providing a widely available framework for investigation of nasal flows.The framework consists of extracting a computational model from computed tomography (CT) or mag- netic resonance imaging (MRI) scans, model refinement and numerical simulations performed usingfoam-extend. The framework was applied to real radiological (CT) scans of the nasal cavity and wasused for numerical simulations of a transient, incompressible, turbulent, single-phase nasal airflow. Thesimulations were performed using a novel approach based on thepUCoupledFoamcoupled incompressiblepressure-velocity solver available infoam-extend, used in conjunction withBlock- SAMG- a block-selectivealgebraic multigrid solution algorithm.The analysis of the results of transient simulations provided insightinto the behaviour of the nasal airflow in a real (patient-specific) geometry. Generally, the simulationsshow how the flow is affected by anatomical barriers, resulting in higher velocities throughout the leftside of the particular anatomy in question. Furthermore, the analysed cross-sections showed the greatestvalues of the velocity magnitudes appearing along the nasal septum (nasal wall separating the cavity), with significantly smaller values noticeable in the peripheral region of the geometry.

Računalna dinamika fluida ; OpenFOAM ; Strujanje u nosnoj šupljini

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