عنوان :
مطالعه تجربي انتقال حرارت جابجايي نانو سيالات غير نيوتني در لوله مدور با اعمال شرايط مرزي متفاوت
گرايش تحصيلي :
مهندسي شيمي
محل تحصيل :
اصفهان : داشگاه صنعتي اصفهان،دانشكده مهندسي شيمي
صفحه شمار :
هجده،144ص.: مصور،جدول،نمودار
يادداشت :
ص.ع.به فارسي و انگليسي
استاد راهنما :
غلامرضا اعتماد،روح ا... باقري
توصيفگر ها :
ضريب انتقال حرارت , خواص رئولوژيكي , ضريب هدايت حرارتي , نانوذره
تاريخ نمايه سازي :
89/1/23
استاد داور :
ارجمند مهرباني،محسن نصراصفهاني،علي اكبر عالم رجبي،محمدرضا طلايي
كد ايرانداك :
ID283 دكتري
چكيده فارسي :
به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي
چكيده انگليسي :
Experimental investigation on convective heat transfer of non Newtonian nanofluids in a circular tube with different thermal boundary conditions Mohammad Hojjat E mail mhojjat@ce iut ac ir Date of submission Feb 06 2010 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree PhD Language Farsi1st supervisor s Name Seyed Gholamreza Etemad E mail etemad@cc iut ac ir2nd supervisor s Name Roholah Bagheri E mail bagheri@cc iut ac irAbstractRheological and thermal behaviors of nanofluids with non Newtonian base fluid wereinvestigated experimentally A solution of 0 5 wt carboxymethyl cellulose in de ionized waterwas used as the base fluid Al2O3 CuO and TiO2 nanoparticles were employed to prepare threekinds of nanofluids Rheological characteristics of the base fluid and Al2O3 CuO and TiO2nanofluids with different concentrations and temperature range of 5 50 C were measured usinga cylindrical rheometer The base fluid and all nanofluids exhibited pseudoplastic behavior Flowbehavior index of nanofluids is less than that of the base fluid and decreases with nanoparticleconcentration At a given particle concentration flow behavior index of nanofluids increases withincreasing temperature Consistency index of nanofluids is larger than that of the base fluid anddecreases with temperature Thermal conductivities of the base fluid and those of the nanofluidswith various concentrations and temperatures were measured Thermal conductivity ofnanofluids shows enhancement in comparison to that of the base fluid Convective heat transfer coefficients of the base fluid and nanofluids in a circular straighthorizontal tube in concentration range 0 1 1 5 vol with two different boundary conditions ofconstant wall temperature and constant wall heat flux were obtained Both laminar and turbulentflow regimes were considered Results of all cases show that the average heat transfercoefficients of nanofluids are significantly larger than the base fluid The heat transfer coefficientof nanofluids increases with increase in both Peclet number and particle concentration Enhancement of heat transfer coefficient of nanofluids increases with particle concentration Inthe case of constant wall temperature enhancement of heat transfer coefficient of nanofluids inturbulent flow is greater than that of the laminar flow but for constant wall heat flux conditionthere exists no significant difference Peclet number has no significant effect on the relative heattransfer coefficient of nanofluids This means that by increase in Peclet number heat transfercoefficients of the base fluid and that of the nanofluid increase with the same order For constantwall heat flux boundary condition the enhancement of local heat transfer coefficient of the basefluid and that of the nanofluid increases with increase in axial distance from the tube inlet Results of local heat transfer coefficients of nanofluids show that the entrance length ofnanofluids is larger than the base fluid and increases with increase in particle concentration Topredict the average heat transfer coefficients of nanofluids with different boundary conditions two equations were obtained by an adequate non linear curve fitting procedure Keywords Non Newtonian nanofluids Heat transfer coefficient Rheological behavior Thermalconductivity anoparticle
استاد راهنما :
غلامرضا اعتماد،روح ا... باقري
استاد داور :
ارجمند مهرباني،محسن نصراصفهاني،علي اكبر عالم رجبي،محمدرضا طلايي
