An Experimental Validation of the Computer Fluid Dynamics of Normal Human Nasal Airflow Using a Precise 3-D Printing Model

Abstract

AbstractComputer Fluid Dynamics (CFD) is a popular method for studying airflow of nasal cavities. However, the data of CFD studies has rarely been validated through experiments. To test the accuracy of CFD computation, we studied the consistency of the air pressure of nasal cavities in the CFD and the experiment. A proportional resin model of a normal human subject’s nasal cavities was created by a 3-d printer with a precision value of 0.1mm. The pressure of 63 check points in the nasal cavities in different breathing states was measured. The experimental data was compared with the data obtained by CFD simulation. At the flow rates of 180 ml s-1 and 560 ml s-1, the pressure in all check points remained highly consistent with the CFD data. At 1100 ml s-1 flow rate, there was a significant deviation in the posterior segment of the nasal cavity during exhalation. The method used in this study to measure the pressure in the nasal cavities can be used in experimental validation of CFD data. The computational methods and the boundary conditions used in this study resulted in a high agreement between the results of the CFD simulation and the experiment.Author SummaryIn the contemporary era, Computer fluid dynamics (CFD) is the mainstream method for studying air flow. Due to the complex anatomical structure of the nasal cavity, the CFD results of the nasal flow have rarely been experimentally verified. This study provides a method to verify the methods and results of nasal CFD. We printed an accurate model of a normal person’s nasal cavity with a high-precision 3D printer. In this nasal cavity model, we set 63 small holes to detect the air pressure of the places we concerned. Three different nasal flow quantity are used to represent different breathing conditions: high (1100 ml s-1), medium (560 ml s-1), and low (180 ml s-1). In medium and low nasal flow quantities, our CFD results are in good agreement with the experimental pressure values. On this basis, we analyzed the characteristics of nasal airflow in normal people. The method used in this study to measure the pressure in the nasal cavities can be used in experimental measurements of the partial resistance of the nasal cavity. With proper modification, it can be applied to the clinical practice for nasal resistance, giving more help for the design of the operation plan.