9506

8788

كارشناسي ارشد

مكانيك- تبديل انرژي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مكانيك

1393

دوازده،69ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

محمدرضا سليم پور

ابراهيم شيراني

5/11/93

احمد صابونچي، توكلي

مهندسي مكانيك

ID8788

يازده چكيده 1 فصل اول مقدمه 1 1 مفهوم تئور ساختار 2 1 2 ميكروكانال جاذب حرارت مستطيلي 5 1 3 كار حاضر 31 فصل دوم بهينه ساز ميكروكانال جاذب حرارت مستطيلي 2 1 بهينه ساز چيدمان ميكروكانال جاذب حرارت مستطيلي 51 2 1 1 بيان فيزيك مسأله 51 2 1 2 تحليل ساختار ميكروكانال 61 2 1 3 مدل رياضي و فرمول بندي 71 2 1 4 بررسي عدد و صحت سنجي 81 2 2 بهينه ساز هندسي ميكروكانال جاذب حرارت مستطيلي 02 2 2 1 بيان فيزيك مسأله 02 2 2 2 هندسه ميكروكانال جاذب حرارت و قيود بهينه ساز 02 2 2 3 حل تحليلي به كمك تئور ساختار 12 2 2 4 معادلات حاكم بر جريان و انتقال حرارت 22 2 2 5 روش عدد و صحت سنجي 32 2 2 6 نتايج و بحث 32 فصل سوم بهينه ساز ميكروكانال جاذب حرارت مستطيلي با شار حرارتي غير يكنواخت 3 1 بهينه ساز هندسي و اثر درجات آزاد بر شكل بهينه ميكروكانال جاذب حرارت مستطيلي 62 3 1 1 جريان مواز سيال خنك كننده افت فشار ثابت 82 3 1 2 جريان متوالي سيال خنك كننده افت فشارغيرثابت 64 3 2 نتايج و بحث 55 3 2 1 تقريب در معادله پوازيه 55 3 2 2 مقايسه نتايج جريان مواز و متوالي 75 فصل چهارم نتيجه گير و پيشنهادها 4 1 نتيجهگير 46

75 Using Rectangular Microchannel Heat Sinks to Remove Non Uniform Heat Flux Nahid Taheri n taheri@me iut ac ir 15th September 2014 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Mohammad Reza Salimpour salimpour@cc iut ac irAbstractThe pieces with micro and nano scales are used in many industries such as electronic design ofcooling channels in computers and electromechanic systems The performance of these pieces isdirectly related to their temperature therefore they should be kept under the favorite temperature Microchannels are an efficient way to absorb the high heat generation of the small electronicpieces For the optimization geometry characteristics of microchannels constructal theory is a goodmeans This theory finds the best structure by predicting the procedure of various designs In this study the arrived heat flux to the bottom surface of microchannel was considered as stepfunction Optimum geometry of the rectangular micro channels has been determined in such a waythat rectangular micro channels configuration would have maximum heat transfer in the unitvolume The numerical simulation was performed on a unit cell Numerical optimization forrectangular cross section was performed Based on the results of this investigation somecorrelations were proposed to predict the optimal hydraulic diameter and the dimensionless heattransfer per unit volume Rectangular micro channel heat sinks were geometrically optimized tofind the highest heat conduction of channels Actually the purpose of the geometric optimizationwas to determine the optimal values of these parameters in such a way that the peak temperature ofthe wall was minimized The output results were verified by the previous results where goodagreements were observed The effects of solid volume fraction aspect ratio hydraulic diameterand heat flux from parallel and serial flows upon the peak temperature of the mentioned micro channels are investigated Moreover these micro channel heat sinks are compared with each otherat their optimal conditions The optimal shapes of rectangular channels were achieved numericallyand compared with the approximate results obtained from scale analysis where good agreementswere observed In addition to the external structure internal structure of the micro channel wasallowed to vary In fact the optimum possible geometry of the micro channel heat sink wasacquired numerically considering another degree of freedom of the micro channel heat sink Usingthe intersection of asymptotes method some equations were derived to calculate the internaldimension of microchannel The rectangular microchannel heat sinks with a non uniform heatfluxes were investigated Considering a fixed length and a fixed volume a 3D numerical simulationwas performed The analytical equations showed that the usage of non uniform heat flux causedchanges in the channel internal dimensions The external dimensions of channel were different forvarious heat flux values even in the optimum situation Moreover it was observed that themaximum temperature in the parallel flow was less than its peer in the serial flow Key wordsConstructal Theory Rectangular Micro Channel Heat sink Optimization Non Uniform Heat Flux

محمدرضا سليم پور

ابراهيم شيراني

احمد صابونچي، توكلي