پديد آورنده :
كشيشيان، نوروان
عنوان :
بررسي ضريب انتقال جرم نانو سيال سيليكا به روش الكتروشيمي در لوله مدور
مقطع تحصيلي :
كارشناسي ارشد
گرايش تحصيلي :
مهندسي شيمي
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده مهندسي شيمي
صفحه شمار :
نه،97ص.: مصور،جدول،نمودار
يادداشت :
ص.ع.به فارسي و انگليسي
استاد راهنما :
محسن نصراصفهاني
استاد مشاور :
نسرين اعتصامي
توصيفگر ها :
هيدروديناميك
تاريخ نمايه سازي :
16/7/92
استاد داور :
احمد محب، مسعود حق شناس فرد
چكيده فارسي :
به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي
چكيده انگليسي :
Investigation of Mass Transfer of Active Ions in Silica Nanofluids Norvan Keshishian n keshishian@ce iut ac ir Date of Submission 2013 3 11 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Mohsn Nasr Esfahany mnasr@cc iut ac ir Abstract In this thesis the effect of silica nanoparticles on mass transfer in a circular tube was studied by using electrochemical limiting current technique in both laminar and turbulent flow regimes Silica nanoparticles with an average size of about 7 13nm was used to prepare electrolyte nanofluids Base fluid was composed of equimolar potassium ferri ferrocyanide and sodium hydroxide The ferricyanide and ferrocyanide are electroactive ions that are diffusing to the cathode and anode surface respectively Sodium hydroxide is inert electrolyte eliminating migration of electroactive ions and establishing diffusion controlled reaction on the electrode surface Underdeveloped concentration and fully developed hydrodynamic profile was considered The validation results for experimental setup showed good agreement between experimental measurements and analytical solution for conditions of developing concentration and fully developed hydrodynamics in laminar flow Measurements for laminar regime indicated that mass transfer coefficient increased with nanofluid volume fraction up to 0 0057 and decreased with increasing the volume fraction of nanoparticles further Maximum enhancement in mass transfer reached 21 at Reynolds number of 326 It was also observed that by constant value of diffusion coefficient as base electrolyte fluid at optimum concentration of 0 005714vol silica nanoparticle the boundary layer thickness has the greatest reduction in thickness Random Brownian motions and stochastic disturbance fields of micro convections hold the key to augment mass transfer also with mediation of electrophoresis near the wall Adsorbed electroactive ions onto nanoparticles that desire to reach the surface of the electrode cause augmentation in mass transfer Hindering act of nanoparticles against diffusion of electroactive ions is liable for decreasing trend for nanofluids with concentration above 0 005714vol In turbulent flow regime presence of silica nanoparticles shed no significant improvement probably because eddies play the key role in transport As silica nanoparticles have low density high shear rate near the wall in turbulent flow regime become more comfortable to take effect for inducing particles migration from wall to the core of the tube therefore due to this effect combined with thinner boundary layer thickness silica nanofluid doesn t demonstrate augmentation effect compared with laminar flow regime Keywords Nano fluid Mass transfer Electrochemical limiting diffusion current technique silica nanoparticle
استاد راهنما :
محسن نصراصفهاني
استاد مشاور :
نسرين اعتصامي
استاد داور :
احمد محب، مسعود حق شناس فرد
