بررسی عددی میدان جریان هوا اطراف مدل مانکن به همراه سیستم تنفسی در یک اتاق با سیستم تهویه

نوع مقاله : مقاله پژوهشی

نویسندگان

1 گروه مهندسی مکانیک،دانشکده مهندسی،واحد شیراز،دانشگاه آزاد اسلامی،شیراز،ایران

2 گروه مهندسی مکانیک دانشگاه آزاد اسلامی واحد شیراز ایران

چکیده

در این مطالعه، میدان جریان اطراف مانکن به همراه دستگاه تنفس در مرکز اتاق دارای سیستم گردش هوا به صورت عددی مطالعه شده است. در حالت اول دریچه های تهویه هوا بر روی دیوار روبروی مانکن و در حالت دوم بر روی دیوار سمت راست قرار گرفته اند. تنفس مانکن در حالت دم با دبی های تنفس 15 ، 20 و 30 لیتر بر دقیقه از ورودی بینی تا انتهای نای شبیه سازی شده است. میدان جریان شامل هوای اطراف مانکن و درون دستگاه تنفس به صورت یکپارچه با حل معادلات پیوستگی و ناویر استوکس در حالت پایا به کمک مدل آشفتگی انتقال تنش برشی گذار در نرم افزار فلوئنت تحلیل شده است. توزیع فشار، شدت آشفتگی ، تنش برشی و خطوط جریان درون دستگاه تنفس بررسی شده است. همچنین توزیع سرعت و خطوط جریان هوا در فضای اتاق و نزدیک صورت در دو حالت مختلف نصب دریچه ها بررسی و مقایسه شده اند. نتایج حاصل برای توزیع شدت آشفتگی نشان می دهد، رژیم جریان داخل دستگاه تنفسی در هر سه دبی تنفسی آشفته می باشد و محل نصب دریچه ها تأثیری بر شدت آشفتگی درون دستگاه تنفس ندارد. همچنین در حالت دوم، سرعت هوا اطراف صورت کمتر بوده و شرایط مناسب تری را از نظر آسایش ایجاد می شود.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Numerical Investigation of Flow Field around a Mannequin Model with Airway System in an Air Conditioned Room

نویسندگان [English]

  • Mehrdad Azhdari 1
  • Mohammad Mehdi Tavakol 2
1 mechanical engineering department,faculty of engineering,Islamic Azad University,Shiraz branch,Shiraz,Iran
2 Department of Mechanical Engineering Shiraz Branch IAU Iran
چکیده [English]

In this study, air flow around a mannequin equipped with a respiratory system at the center of ventilated room was studied numerically. In the first mode the air conditioner dampers were installed on the front wall and in the second modes they were installed on the right side wall. The inhalation rates of 15, 20 and 30 lit/min were simulated from the nostril inlet to the end of trachea. Flow field including the region around mannequin and airway, integrally, was evaluated by solving  the Navier-Stokes and continuity equations in steady state condition by means of k-ω-SST transition turbulence model in the Ansys-Fluent software. Pressure distribution, turbulence intensity, shear stress and streamlines were evaluated inside the airway passage. Furthermore, the velocity distribution and streamlines near the mannequin face for two ventilation modes were analyzed. According to the results for the turbulence intensity distribution the turbulent flow was observed inside the respiratory system for all of the breathing rates and location of the air condition dampers did not affect the turbulence intensity distribution inside the respiratory system. In addition, in the second mode, the lower air velocity was obtained around the mannequin face and better comfort condition inside the room was maintained.

کلیدواژه‌ها [English]

  • mannequin
  • Respiratory system
  • air conditioning
  • Inhalation flow rate
[1]  Y. Liu, E.A. Matida, J. Gu, M.R. Johnson, Numerical simulation of aerosol deposition in a 3-D human nasal cavity using RANS, RANS/ EIM, and LES, Journal of Aerosol Science, 38(7) (2007) 683-700.
[2] Y.-S. Cheng, Y. Yamada, H.-C. Yeh, D.L. Swift, Diffusional deposition of ultrafine aerosols in a human nasal cast, Journal of Aerosol Science, 19(6) (1988) 741-751.
[3]  Y. Cheng, H. Yeh, R. Guilmette, S. Simpson, K. Cheng, D. Swift, Nasal deposition of ultrafine particles in human volunteers  and  its relationship to airway geometry, Aerosol Science and Technology, 25(3) (1996) 274- 291.
[4]  C. Ball, M. Uddin, A. Pollard, High resolution turbulence modelling of airflow in an idealised human extra-thoracic airway, Computers & Fluids, 37(8) (2008) 943-964.
[5] J. Wen, K. Inthavong, J. Tu, S. Wang, Numerical simulations for detailed airflow dynamics in a human nasal cavity, Respiratory Physiology & Neurobiology, 161(2) (2008) 125-135.
[6]  J.-H. Lee, Y. Na, S.-K. Kim, S.-K. Chung, Unsteady flow characteristics through a human nasal airway, Respiratory Physiology & Neurobiology, 172(3) (2010) 136-146.
[7]  J.H. Zhu, H.P. Lee, K.M. Lim, S.J. Lee, D.Y. Wang, Evaluation and comparison of nasal airway flow patterns among three subjects from Caucasian, Chinese and Indian ethnic groups using computational fluid dynamics simulation, Respiratory Physiology & Neurobiology, 175(1) (2011) 62-69.
[8]  J. Xi, A. Berlinski, Y. Zhou, B. Greenberg, X. Ou, Breathing resistance and ultrafine particle deposition in nasal–laryngeal airways of a newborn, an infant, a child, and an adult, Annals of Biomedical Engineering, 40(12) (2012) 2579-2595.
[9]  M. Rahimi-Gorji, O. Pourmehran, M. Gorji- Bandpy, T. Gorji, CFD simulation of airflow behavior and particle transport and deposition in different breathing conditions through the realistic model of human airways, Journal of Molecular Liquids, 209 (2015) 121-133.
[10]  M. Rahimi-Gorji, T.B. Gorji, M. Gorji- Bandpy, Details of regional particle deposition and airflow structures in a realistic model of human tracheobronchial airways: two-phase flow simulation, Computers in Biology and Medicine, 74 (2016) 1-17.
[11]  T.R. Anthony,  M.R. Flynn, CFD  model for  a 3-D inhaling mannequin: verification and validation, Annals of Occupational Hygiene, 50(2) (2005) 157-173.
[12]  D. Rim, A. Novoselac, Transport of particulate and gaseous pollutants in the vicinity of a human body, Building and Environment, 44(9) (2009) 1840-1849.
[13]  C.M. King Se, K. Inthavong, J. Tu, Inhalability of micron particles through the nose and mouth, Inhalation Toxicology, 22(4) (2010) 287-300.
[14]  T.T. Zhang, H. Li, S. Wang, Inversely tracking indoor airborne particles to locate their release sources, Atmospheric Environment, 55 (2012) 328-338.
[15]  I. Goldasteh, G. Ahmadi, A. Ferro, CFD simulation of particle transport and dispersion in indoor environment by  human  walking,  in: ASME 2012 Fluids Engineering Division Summer Meeting collocated with the ASME 2012 Heat Transfer Summer Conference and the ASME 2012 10th International Conference on Nanochannels, Microchannels, and Minichannels, American Society of Mechanical Engineers, 2012, pp. 267-272.
[16]J. Tu, K. Inthavong, G. Ahmadi, Computational fluid and particle dynamics in the human respiratory system, Springer Science & Business Media, 2012.
[17]Y. Tao, K. Inthavong, J. Tu, Computational fluid dynamics study of human-induced wake and particle dispersion in indoor environment, Indoor and Built Environment, 26(2) (2017) 185-198.
[18]F. Menter, R. Langtry, S. Völker, Transition modelling for general purpose CFD codes, Flow, Turbulence and Combustion, 77(1-4) (2006) 277-303.
[19]J. Wheatley, T. Amis, L. Engel, Nasal and oral airway pressure-flow relationships, Journal of Applied Physiology, 71(6) (1991) 2317-2324.
[20]F. Chen, C. Simon, A.C. Lai, Modeling particle distribution and deposition in indoor environments with a new drift–flux model, Atmospheric Environment, 40(2) (2006) 357- 367.
[21]A. Standard, Standard 55-2010, Thermal Environmental Conditions for Human Occupancy. Atlanta: American Society of Heating, Refrigerating, and Air-Conditioning Engineers, in, Inc, 2004.