8674

8055

كارشناسي ارشد

تبديل انرژي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مكانيك

1392

بيست و يك،174ص.: مصور،جدول،نمودار (رنگي)

ص.ع.به فارسي و انگليسي

محمدرضا سليم پور

ابراهيم شيراني

19/1/93

احمد صابونچي، محمدرضا توكلي

مهندسي مكانيك

ID8055

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

233 Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Mohammad Reza Salimpour Salimpour@cc iut ac irAbstract In recent years many efforts have been devoted to analysis of reological and thermal behaviors ofnanofluids The present research is a numerical study of heat transfer and pressure drop of two nanofluidsincluding water and ethylene glycol water as base fluid with Al 2O3 and CuO nano particles through aaxisymmetric sinusoidal walled tube In this research numerical investigation has been done for variouscombinations of base fluid nanoparticle size and concentration through straight and sinusoidal tube Simulation has been done using Ansys CFX software in laminar flow Besides the thermal boundarycondition of constant uniform heat flux on the tube wall was applied The results show that the increase ofReynolds number and nano particle volume concentration have considerable effects on the heat transfercoefficient enhancement With similar Reynolds number and volume concentration theCuO nanofluidwith 2 has higher heat transfer coefficient than that of Al 2O3 especially at higher nano particleconcentrations Furthermore the amount of heat transfer enhancement with volume concentrationincrement in ethylene glycol water base fluid is more considerable than that of water for two nano particletypes especially for CuO For two types of nano particles the heat transfer coefficient is decreased withnano particle diameter increase At constant Reynolds numbers and volume concentrations the longer waveamplitude can increase heat transfer coefficient thus the sinusoidal tube can improve the thermalperformance of nanofluids Two passive methods which used in this study lead to higher pressure drops For all the fluids under consideration in this study pressure drop escalates with Reynolds number Additionof nanoparticle to base fluid leads to rise in pressure drop and this effect is more vigorous for higherconcentration Regardless to the nano particle type and its volume concentration the skin frictioncoefficient decreases with Reynolds number increase But at constant Reynolds number longer waveamplitude results in higher friction coefficient Both effects of pressure drop and heat transfer of fluid flowhave been investigated simultaneously by using performance evaluation criteria Similar to base fluid theperformance evaluation criteria is reduced with Reynolds number increase Moreover at constant Reynoldsnumbers the performance evaluation criteria decreases with volume concentration increase The resultsshow that in high wave amplitude sinusoidal tubes performance evaluation criteria deteriorate but in lowamplitudes sinusoidal tubes have better performances than straight ones Keywords Heat transfer Nanofluid Sinusoidal tube Pressure drop Performance evaluation criteria Constant heat fluxt Isfahan University of Technology Department of Mechanical Engineering

محمدرضا سليم پور

ابراهيم شيراني

احمد صابونچي، محمدرضا توكلي