Experimental and modeling study of heat transfer enhancement of TiO 2 /SiO 2 hybrid nanofluids on modified surfaces in p
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Experimental and modeling study of heat transfer enhancement of TiO2 /SiO2 hybrid nanofluids on modified surfaces in pool boiling process Afsaneh Mehralizadeh, Seyed Reza Shabaniana , Gholamreza Bakeri Department of Chemical Engineering, Babol Noshirvani University of Technology, Shariati Ave, Babol 47148-71167, Iran Received: 13 June 2020 / Accepted: 25 September 2020 © Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract The thermal conductivity of working fluids has been dramatically improved by the implementation of nanoparticles. In this experimental study, the influence of TiO2 and SiO2 nanoparticles on the pool boiling heat transfer coefficient (HTC) of the nanofluid is thoroughly investigated. The results indicate that HTC of hybrid nanofluid of TiO2 –SiO2 –water is considerably higher than that of single nanofluids TiO2 –water and SiO2 –water systems. The effects of the nanofluid concentration and surface modification on HTC were investigated for two main working fluids of water and a mixture of ethylene glycol (EG)-water. Experimental evidence shows that the highest values of heat flux and HTC are obtained at 0.05% concentration of the hybrid nanofluid. Furthermore, the results show that changing the plain surface to the surface with circular channels and intersection lines (CC-IL) leads to considerable enhancement in HTC for all nanofluids. Two intelligent methods of artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS) have also been developed for the prediction of the experimental HTCs. The results indicate the prediction precision of the ANN model is higher than that of ANFIS. The RMSE and AARD of the ANN model are 1.05 mKW 2 C and 3.02%, respectively. Abbreviations AARD ANFIS ANN CC CC-IL CHF CNC FESEM HTC MF MLP
Average absolute relative deviation Adaptive neuro-fuzzy inference system Artificial neural network Circular microchannels Circular microchannels intersection lines Critical heat flux Computer numerical control Field emission scanning electron microscope Heat transfer coefficient Membership function Multilayer perceptron
a emails: [email protected]; [email protected] (corresponding author)
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RMSE SEM
Eur. Phys. J. Plus
(2020) 135:796
Root-mean-square errors Scanning electron microscopy
List of symbols D EG K Q Re T W W
Distance between two thermocouples (m) Ethylene glycol Thermal conductivity (W/m K) Heat flux (W/cm2 ) Relative deviation Temperature (°C) Mass of nanoparticle (kg) Distilled water
Greek symbol P Density (Kg/m3 ) Φ Nanoparticle volume fraction
Subscripts B Ms N Ps S Sat Wall
Base fluid Modified surface Nanoparticle Plain surface Surface Saturation Heater surface
1 Introduction Boiling process and thorough understanding of its underlying phenomenon are of great significance in many engineering fields like cooling systems for air conditioning, refrigeration and electronic devices, together with cooling and boiling systems in many industries r
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