7262

6768

كارشناسي ارشد

تبديل انرژي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مكانيك

1391

چهارده، 105ص: مصور، جدول، نمودار

ص.ع. به فارسي و انگليسي

احمدرضا عظيميان

محمد اميني

21/8/91

ابراهيم شيراني، احمدرضا پيشه ور

1396/09/21

كتابنامه

مكانيك

مهندسي مكانيك

ID6768

به فارسي و انگليسي: قابل رويت در نسخه ديجيتال

Investigation and Simulation of Wall Models and Accommodation Coefficients in Nano channel Flow by Using MDS Iman Tasdighi Iman tasdighi@gmail com Date of Submission 2012 04 16 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Ahmad Reza Azimian azimian@cc iut ac irAbstract Nowadays numerical methods are as complement of experimretal works for nano scale studies Molecular dynamics simulation MDS is more determined method for molecular simulation We employMDS for Poiseuille flow simulation in nano channel In this thesis main porpuse is about implicit wallmodels instead of explicit wall models Various implicit or stochastic wall models sach as spcular anddiffuse Maxwell Maxwel Type CL and CLL Maxwell Yammamuto thermal wall and Nokilla investigated and use them for simulation of Poisseul flow in nanochannel These wall models can becalculated velocity components of reflective molecules that collide with implicit wall With this method wecan omit molecules of wall and predict the outcoming of it s velocity after collide with wall Mostadvantage of these models is that they can reduce time of simulation Accommodation coefficient AC is afactor for determination of properties change via collides with wall In the recent years open source softwares widely use for various scientific subjects such as molecularscience and molecular simulation LAMMPS Atomic Molecular Massively Parallel Simulator Large scale is one of the more applicable and famous of them In the 5 recent years many of researchers use it for theirsubjects and develope it for various subject of molecular science simulation We use it for our subject Scripts of Implicit wall models and calculation of accommodation coefficients are not in it and we shouldadd their scripts with C Programming accordance to MPI library and Objects Oriented Programming tothe LAMMPS In the first chapter present basics of MD method and its algorithms in chapter two an introduction tovarious implicit wall models and accommodation coefficient is given and details of them studied In chapterthree explain the simulation details that used in this thesis In the chapter four first verified Script ofPoiseuille flow with 3D simulation of liquid argon confined in Pt walls and then simulate 2D poiseuille ofgas and liquid argon with explicit model and implicit wall models by employing various conditions forces density number and temperature Then present the results of these simulations These results consist ofvelocity and shear stress profile across channel and accommodation coefficient of them and compare theresults of all wall models together Then conclude that CLL and Maxwell Yammamotu wall models are thebest model for our simulation In the end there is a summary of thesis and suggestions for further studies This thesis consists of an addendum for more explain about Maxwell distribution and related equations We can concluded the implicit wall models can be predicting the properties of fluids Gas and Liquidof Argon in nano channel The results deduced that specular wall model has good agreement withsimulation of smooth wall explicit wall It should be reviewed that implicit wall models except specularand nokilla models needed ACs for each model These ACs calculated from explicit wall simulation andthen used them in implicit models Keywords Explicit wall and implicit wall models Accommodation coefficient Nanochannel Poiseuille flow and molecular dynamic

احمدرضا عظيميان

محمد اميني

ابراهيم شيراني، احمدرضا پيشه ور