Investigation On Nasal Airflow Of Malaysian Females Using Cfd

• Main Author: Lee, Chih Fang
• Format: Thesis
• Language: English
• Published: 2014
• Subjects: T1-995 Technology(General)
• Online Access: http://eprints.usm.my/36896/1/LEE_CHIH_FANG_24_Pages.pdf; http://eprints.usm.my/36896/
• Institution: Universiti Sains Malaysia

Inabilities of objective measurement methods to obtain various important information regarding human nasal airflow leads to the application of Computational Fluid Dynamics (CFD) to study and analyze the complicated structures of the nasal cavity. This research focuses on detailed investigation of Malaysian female nasal cavities which includes mucous effects, standardized model and disease cases. In this study, mucous layer effects on nasal airflow were studied by thickening the mucous layer from 5 to 50 μm and analysis were carried out with mass flow rate ranging from 7.5 to 20 L/min. Analysis results of non-mucous effects were compared with the thickening mucous layer effects. Based on the results obtained, healthy mucous layer thickness within the range of 5 to 30 μm caused insignificant effects towards the total nasal airflow. Unique and distinctive features of the human nasal cavities require generalization of its geometry and thus, this study creates a standardized female Malaysian nasal cavity. The methodology implemented in this research involves simple programming of averaging pixel values from a set of Computational Tomography (CT) scans. Therefore, it is simpler and requires shorter time compared to other method used in previous research. The average velocity magnitudes calculated from the four individual models match closely with the standardized model with a difference of less than 20%. This proves that the generated model can represent an average and standardized model of an adult Malaysian female. Huge differences from the comparisons with the standardized model of different population shows the need for a standardized model which represents different xx population due to the diversity of the human nasal cavities. In addition to that, Particle Image Velocimetry (PIV) experimental work and acoustic rhinometry measurements were carried out for validation purposes. Good agreement between the computational, calculation, experimental and rhinometry measurements results provides a strong validation of the computational analysis conducted in this research. As an initial step towards implementing virtual surgery in the future, this study analyzed the pre-operation and post-operation CT scans of the two female patients with nasal diseases (sinusitis). CFD analysis for pre and post-operation conditions allow better observation of the infected areas as well as the nasal airflow behavior such as velocity magnitudes in order to assist rhinologist to view the effects of the surgeries carried out. The results and observations obtained from this research bring a step forward in advancement of virtual surgery in the future and will be beneficial in clinical research development.