5517

5177

كارشناسي ارشد

تبديل انرژي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مكانيك

1389

چهارده،78ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

محمود اشرفي زاده

ابراهيم شيراني

19/8/89

محسن ثقفيان، احمد صداقت

مهندسي مكانيك

ID5177

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Lattice Boltzmann Simulation of Periodic Inlet and Outlet Flow in a Cylindrical Enclosure Mehdi Falsafioon m falsafioon@gmail com 5th April 2010 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc language Farsi Supervisor Dr Mahmud Ashrafizaadeh Email Address mahmud@cc iut ac ir Abstract In this project the main goal is simulation and investigation of low Reynolds number flows Re 1 in a cylindrical enclosure which is expanded and contracted in a specified time period The angle of cylinder opening is assumed constant at all generations and time independent for a self similar geometry In fact study of this case help us to have a good understanding of air flow pattern inside the acinus of human pulmonary organ Alveoli constitute the gas exchange units necessary for oxygen and carbon dioxide exchange with capillary blood vessels which are embedded within the alveolar membranes Considering the cases described above initially tried to present the conditions and the parameters of the problem and then tried to introduce Lattice Boltzmann method and to compare this method with other methods applied to solve fluid mechanic problems Finally there is a complete discussion about all flow patterns inside an alveolar in various generations Dimensions applied for these simulations are in accordance with recent measurements for adult humans Results for the rigid wall simulation case illustrate that convection in the duct induces a shear flow across the alveolus opening thus generating a recirculation region filling the entire alveolar cavity Results for the moving wall case real state determine that the rhythmic wall motion induces a small portion of the flow travels along the alveolar walls during breathing period Thus the fundamental difference compared to the rigid alveolus case is that net convective transport from the duct into the alveolus now exists Also the resulting alveolar flow patterns are largely time independent and governed by the ratio of the alveolar to ductal flow rates This ratio depends uniquely on geometrical configuration such that alveolar flow patterns may be entirely determined by the location of the alveoli along the acinar tree Key Words Alveoli Periodic Flow Lattice Boltzmann Method Moving Curve Boundary Condition

محمود اشرفي زاده

ابراهيم شيراني

محسن ثقفيان، احمد صداقت