پديد آورنده :
خليلي، ابراهيم
عنوان :
بررسي عددي و آزمايشگاهي توزيع غلظت نانوذرات در انتقال حرارت جابجايي آزاد نانوسيال غيرهمگن
گرايش تحصيلي :
تبديل انرژي
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده مكانيك
صفحه شمار :
شانزده، [130]ص.: مصور، جدول، عكس(رنگي)، نمودار
يادداشت :
ص. ع. به فارسي و انگليسي
استاد راهنما :
احمد صابونچي
استاد مشاور :
محسن ثقفيان
توصيفگر ها :
براوني , ترموفرسيس
استاد داور :
ابراهيم شيراني، محمدرضا سليم پور; داور خارجي: محمد حسن سعيدي، حسين شكوهمند
تاريخ ورود اطلاعات :
1395/12/01
كد ايرانداك :
ID997 دكتري
چكيده انگليسي :
130 Numerical and Experimental Investigation of Natural Convection Heat Trasnfer Of Non homogeneous Nanofluid Due To Brownian Motion Nanolayer Formation and Therophoresis Effect Ebrahim Khalili e khalili@me iut ac ir Date of Submission Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree Phd Language FarsiSupervisor Dr Ahmad Saboonchi ahmadsab@cc iut ac irAdvisor Dr Mohsen Saghafian saghafian@cc iut ac irAbstractThe objective of this thesis is to investigate experimentally and numerically the non homogenousdistribution of nanoparticles in the nanofluid by natural convection heat transfer inside a squareenclosure There are some phenomenon such as fluid motion Brownian effect thermophoresiseffect and gravity which cause nanoparticles movements throughout the nanofluid Anexperimental set up was built to carefully take micro litter samples of nanofluid from a8 8 18 cm3 square cavity The nanofluid was prepared using 20nm gamma type Al2O3nanoparticles dispersed in deionized distilled water The experiments were done for threeRayleigh numbers 0 992 107 0 51 108 and 1 53 108 and the particle loading of 1 was constantduring the experiments The contours of nanoparticle fraction shows that the assumption of non homogeneity is correct and the regions of high and low nanoparticle volume concentration aredistinguishable The fluid motion is the most important factor that may come in to play especiallyat higher Rayleigh number and causes the maximum differences between measured nanoparticleconcentration The result showed that the differences between maximum and minimum volumefraction in the whole cavity increases from 18 at Ra 0 992 107 to 28 76 at Ra 1 51 108 Itwas observed that the average nanoparticle volume fraction along cold wall is 3 10 greater thanthat along hot wall for minimum Ra number however at higher Ra numbers this difference wouldweaken To check precision of replicates and ensure accuracy the data were analyzed usinganalysis of variance method ANOVA method In addition to experoimental part a numerical study has been conducted for two differentgeometry A square cavity and a cylindrical enclosure Numerical methods was used for thecomputational analysis of natural convection heat transfer from fire hot tube plate to the coldtube plate inside the water Al2O3 nanofluid in enclosure cavity using alumina nanoparticles Themathematical model is based on two dimensional continuity momentum energy and volume
استاد راهنما :
احمد صابونچي
استاد مشاور :
محسن ثقفيان
استاد داور :
ابراهيم شيراني، محمدرضا سليم پور; داور خارجي: محمد حسن سعيدي، حسين شكوهمند
