• Proceedings of the KSME Conference
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• 2005.11a
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• pp.60.1-60.1
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• 2005

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.498-501
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• 2008

Knowledge of airflow characteristics in nasal cavities is essential to understand the physiological and pathological aspects of nasal breathing. Several studies have utilized physical models of the healthy nasal cavity to investigate the relationship between nasal anatomy and airflow. In our laboratory, there have been a series of experimental investigations on the nasal airflow in normal, abnormal, and deformed nasal cavity models cavity models by PIV under both constant and periodic flow conditions. In this time normal and several deformed nasal cavity models, which simulate surgical operation, Turbinectomy, are investigated numerically by the FVM general purpose code and PIV analysis. The comparisons of these results are appreciated. Dense CT data and careful treatment of model surface under the ENT doctor's advice provide more sophisticated cavity models. The Davis (LaVision Co.) code is used for PIV flow analysis. Average and RMS distributions have been obtained for inspirational and expirational nasal airflows in the normal and deformed nasal cavities.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.6
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• pp.461-467
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• 2009

Knowledge of airflow characteristics in nasal cavities is essential to understand the physiological and pathological aspects of nasal breathing. Several studies have utilized physical models of the healthy nasal cavity to investigate the relationship between nasal anatomy and airflow. In our laboratory, there have been a series of experimental investigations on the nasal airflow in normal, abnormal, and deformed nasal cavity models by PIV under both constant and periodic flow conditions. In this time normal and several deformed nasal cavity models, which simulate surgical operation, Turbinectomy, are investigated numerically by the FVM general purpose code and PIV analysis. The comparisons of these results are appreciated. Dense CT data and careful treatment of model surface under the ENT doctor's advice provide more sophisticated cavity models. The Davis (LaVision Co.) code is used for PIV flow analysis. Average and RMS distributions have been obtained for inspirational and expirational nasal airflows in the normal and deformed nasal cavities.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1479-1483
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• 2008

The three main physiological functions of nose are air-conditioning, filtering and smelling. Knowledge of airflow characteristics in nasal cavities is essential to understand the physiological and pathological aspects of nasal breathing. Several studies have utilized physical models of the healthy nasal cavity to investigate the relationship between nasal anatomy and airflow. In our laboratory, there have been a series of experimental investigations on the nasal airflow in normal and deformed nasal cavity models by PIV under both constant and periodic flow conditions. In this time, airflow inside normal nasal cavity is investigated numerically by the FVM general purpose code. The comparisons with PIV measurement are appreciated. Heat and humidity transfer is dealt numerically. Dense CT data and careful treatment of model surface under the ENT doctor’s advice provide more sophisticated cavity models for both PIV experiment and numerical grid system. Average and RMS velocity distributions have been obtained for inspirational and expirational nasal. Temperature distribution, heat and humidity transfer through the mucosa are obtained.

• 한국가시화정보학회:학술대회논문집
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• 2005.12a
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• pp.93-98
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• 2005

The mean and RMS velocity field of the respiratory gas flow in tile human airway was studied experimentally by particle image velocimetry(PIV). Some researchers investigated the airflow for the mouth breathing case both experimentally and numerically. But it is very rare to investigate the airflow of nose breathing in a whole airway due to its geometric complexity. We established the procedure to create a transparent rectangular box containing a model of the human airway for PIV measurement by combination of the RP and the curing of clear silicone. We extend this to make a whole airway including nasal cavities, larynx, trachea, and 2 generations of bronchi. The CBC algorithm with window offset (64*64 to 32*32) is used for vector searching in PIV analysis. The phase averaged mean and RMS velocity distributions in Sagittal and coronal planes are obtained for 7 phases in a respiratory period. Some physiologic conjectures are obtained. The main stream went through the backside of larynx and trachea in inspiration and the frontal side in expiration. There exist vortical motions in inspiration, but no prominent one in expiration.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1687-1692
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• 2004

Airflow in the nasal cavity of a normal Korean adult is investigated experimentally by tomographic PIV measurement. Knowledge of airflow characteristics in nasal cavities is essential to understand the physiology and pathology aspects of nasal breathing. Several studies have utilized physical models of the healthy nasal cavity to investigate the relationship between nasal anatomy and airflow. All of these researches on nasal airflow are under the condition of constant flow-rate. In this study, nasal cavity flow with the physiological period is investigated by tomographic PIV, for the first time. A pumping system that can produce the periodic flow is created. Thanks to a new method for the model casting by a combination of the rapid prototyping and curing of clear silicone, a transparent rectangular box containing the complex nasal cavity can be made for PIV. The CBC PIV algorithm is used for analysis. Phase-averaged mean and RMS velocity distributions are obtained for inspirational and expiration nasal airflows. The comparison with the constant flow case is appreciated. There exist many flow patterns depending on each phase.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.1 s.232
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• pp.103-109
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• 2005

Airflow in the nasal cavity of a normal Korean adult is investigated experimentally by tomographic PIV measurement. Knowledge of airflow characteristics in nasal cavities is essential to understand the physiology and pathology aspects of nasal breathing. Several studies have utilized physical models of the healthy nasal cavity to investigate the relationship between nasal anatomy and airflow. All of these researches on nasal airflow are under the condition of constant flow-rate. In this study, nasal cavity flow with the physiological period is investigated by tomographic PIV, for the first time. A pumping system that can produce the periodic flow is created. Thanks to a new method for the model casting by a combination of the rapid prototyping and curing of clear silicone, a transparent rectangular box containing the complex nasal cavity can be made for PIV, The CBC PIV algorithm is used for analysis. Phase-averaged mean and RMS velocity distributions are obtained for inspirational and expiration nasal airflows. The comparison with the constant flow case is appreciated. There exist many flow patterns depending on each phase.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.8
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• pp.749-754
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• 2010

Knowledge of the characteristics of airflow in nasal cavities is essential to understand the physiological and pathological aspects of nasal breathing. In our laboratory, a series of experimental investigations on the nasal airflow was conducted; airflow in models of normal and deformed nasal cavities under both constant and periodic flow conditions was studied by PIV. Some of the patients with asymmetric nasal cavities experience pain or discomfort, while other patients with asymmetric nasal cavities do not experience pain. Airflows inside asymmetric nasal cavities with and without obstructions due to a bent nasal septum are investigated both experimentally by PIV and numerically by using the general-purpose FVM code in order to determine the reason for the above-mentioned discrepancy. The comparisons between two cases are tried. Heat and humidity distribution are investigated numerically.