9385

8667

كارشناسي ارشد

مكانيك- تبديل انرژي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مكانيك

1393

دوازده،74ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

محمدرضا سليم پور

ابراهيم شيراني

1/10/93

علي اكبر عالم رجبي، محمدرضا توكلي

مهندسي مكانيك

ID8667

75Constructal Design of Reverting Microchannels for Convective Cooling of a Square Piece Mahsa Farzaneh Mahsa farzaneh@me iut ac ir 16th September 2012 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Mohammad Reza Salimpour salimpour@cc iut ac irAbstractHeat and fluid flow are widely used in many industrial applications With developing the production ofmicro and nano scale pieces improvement in their thermal performance is one of the most important topics These pieces could be used in the electronic computer and electromechanical systems The speed ofprocessors in these pieces relates directly to their temperature so keeping in the appropriate temperature isnecessary The target is to reach the maximum heat transfer rate with considering some limitations such ascooling channels volume constant heat flux and the actual temperature of the piece Various methods weresuggested for optimization of electronic systems with high heat flux production One of the useful methodsto improve heat transfer in electronic devices in various configurations is the use of channels with smallerdimensions down to micro and nano scales because of high heat transfer coefficient For example usingforced convection inside the micro channels as the heat sink has been proposed for cooling the electronicpieces that have a high temperature The micro channels arrangement has a sensible effect on heat transfer rate Constructal theory is a methodof geometrical optimization with inspire of nature The constructal theory concepts which introduced firstby Bejan deals dominantly with shapes and geometry of flow structures In the constructal theory flowstructure is developed to access the best performance during time The designer assembles systemcomponents to achieve the maximum performance In this project convective heat transfer cooling of asquare shape piece with internal heat generation was considered The coolant enters at the center of thepiece and flows through the diagonal channel path Distributed fluid is used again for cooling by the secondfluid collector network that located below the first microchannels network Flow enters the revertingchannels by vertical interconnections It merges again successively into a larger channel until it leaves thenetwork through the central region The purpose of this study is the analysis of the system configurationsomehow the thermal resistance reaches its minimum value In this project number of branches length andwidth ratio in each branch in tree network are investigated Using of reverting microchannels led toconsiderable decrement in maximum temperature The computed results show that the number of brancheshad a noticeable effect on the maximum value and uniformity of temperature In the channels with highpressure drop the contribution of mass flow is lower so the temperature of zones near these channelsincreases Keywords Constructal theory Square piece Convective cooling geometrical optimization

محمدرضا سليم پور

ابراهيم شيراني

علي اكبر عالم رجبي، محمدرضا توكلي