Numerical simulation of normal nasal cavity airflow in Chinese adult: a computational flow dynamics model

Abstract

Our purpose is to simulate the airflow inside the healthy Chinese nose with normal nasal structure and function by computational fluid dynamics (CFD) method and to analyze the relationship between the airflow and physiological function. In this study, we used the software MIMICS 13.0 to construct 20 3-dimensional (3-D) models based on the computer tomography scans of Chinese adults' nose with normal nasal structure and function. Thereafter, numerical simulations were carried out using the software FLUENT 6.3. Then the characteristics of airflow inside the airway and sinuses were demonstrated qualitatively and quantitatively in steady state. We found that during the inhalation phase, the vortices and turbulences were located at anterior part and bottom of the nasal cavity. But there is no vortex in the whole nasal cavity during the expiratory phase. The distributions of pressure and wall shear stress are different in two phases. The maximum airflow velocity occurs around the plane of palatine velum during both inspiratory and expiratory phases. After the airflow passed the nasal valve, the peak velocity of inhaled airflow decreases and it increases again at the postnaris. Vice versa, the exhaled airflow decelerates after it passed the postnaris and it accelerates again at nasal valve. The data collected in this presentation validates the effectiveness of CFD simulation in the study of airflow in the nasal cavity. Nasal airflow is closely related to the structure and physiological functions of the nasal cavity. CFD may thus also be used to study nasal airflow changes resulting from abnormal nasal structure and nasal diseases.

Computational modeling and validation of human nasal airflow under various breathing conditions

“…The laminar model has been commonly adopted for simulating nasal airflow at relatively low flow rates when the turbulence kinetic energy is negligible (Croce et al, 2006; Keyhani et al, 1995; Wang et al, 2016), but this approach has been questioned (Doorly et al, 2008a; Doorly et al, 2008b). To better evaluate the flow transition to turbulence, Reynolds-averaged Navier-Stokes (RANS) with two-equation turbulence models have been normally applied, such as k- model (Tan et al, 2012; Zhao et al, 2006), standard k- model (Zhang and Kleinstreuer, 2011), Shear Stress Transport (SST) k- model (Mylavarapu et al, 2009), and Reynolds Stress Model (RSM) (Ball et al, 2008). With the advancement of high performance computing, in recent years, many groups have considered large eddy simulation (LES) as an alternative approach for modeling airflow in human respiratory systems (Lu et al, 2014; Xi et al, 2016).…”

Generation and Visual Exploration of Medical Flow Data: Survey, Research Trends and Future Challenges

“…CFD or flow imaging focused literature tries to achieve an overview of the vector flow field through its dense visual sampling by integral curves [CVS*15, THW*12], arrow glyphs [Buo98] or particles [XSZ*14]. This results in cluttered visualizations.…”

Computational fluid dynamics simulation of the upper airway of obstructive sleep apnea syndrome by Muller maneuver

“…Numeric simulation was performed using CFD software (ANSYS12.0-CFX, ANSYS, America). The flow in the airway was assumed to be turbulent and incompressible [11] . The RNG-based turbulence model was used in the study.…”