The incompressibility assumption in computational simulations of nasal airflow. Issue 8 (11th June 2017)

• Record Type: Journal Article
• Authors: Cal, Ismael R.; Cercos-Pita, Jose Luis; Duque, Daniel
• Is Part Of: Computer methods in biomechanics and biomedical engineering. Volume 20:Issue 8(2017)
• Page Start: 853
• Page End: 868
• Publication Date: 2017-06-11
• Subjects: Nasal cavity -- CFD -- nasal airflow -- incompressibility -- openFOAM; Biomechanics -- Data processing -- Periodicals; Biomedical engineering -- Periodicals; Biomechanics -- Periodicals; Biomedical Engineering -- methods -- Periodicals; Computing Methodologies -- Periodicals; 612.7
• DOI: 10.1080/10255842.2017.1307343
• Languages: English
• ISSNs: 1025-5842

Abstract

Abstract: Most of the computational works on nasal airflow up to date have assumed incompressibility, given the low Mach number of these flows. However, for high temperature gradients, the incompressibility assumption could lead to a loss of accuracy, due to the temperature dependence of air density and viscosity. In this article we aim to shed some light on the influence of this assumption in a model of calm breathing in an Asian nasal cavity, by solving the fluid flow equations in compressible and incompressible formulation for different ambient air temperatures using the OpenFOAM package. At low flow rates and warm climatological conditions, similar results were obtained from both approaches, showing that density variations need not be taken into account to obtain a good prediction of all flow features, at least for usual breathing conditions. This agrees with most of the simulations previously reported, at least as far as the incompressibility assumption is concerned. However, parameters like nasal resistance and wall shear stress distribution differ for air temperatures below C approximately. Therefore, density variations should be considered for simulations at such low temperatures.