Experimental and numerical investigations of heat and mass transfer studies using nanofluids

Abstract

newline Nanofluids are stable suspensions of nanoparticles of 1-100 nm size in the base fluids like water, amines and ethylene glycol, etc., nanofluids have better thermo-physical properties than the respective base fluid. The first chapter of the thesis discusses the reason behind these better thermo-physical properties, the advantages of nanofluids, disadvantages of nanofluids. Synthesis methods and characterization techniques for the nanofluid properties are also described in chapter 1. The last section of the chapter is dedicated to the various sectors of the industry and application areas of nanofluids. Nanofluids are also used in solar panels because of their increased optical properties. Nanofluids have also shown an increase in CO2 absorption than conventional amines like methyl ethyl amine and dimethyl ethyl amine. Thus, for my Ph.D. work, I have chosen four applications of nanofluids in different sectors. The first application of nanofluids is the application of nanofluids in the solar collector. The role of nanofluid in the solar collector is to exchange the energy from the sun to the targeted application. Thus, chapter 2 is dedicated to this study. Similarly, in chapter 3; the application of nanofluids in the car radiator is discussed. The role of nanofluid is to exchange the energy from the engine coolant with the surrounding. In chapter 4, the role of nanofluids in the Boiling process is discussed and in Chapter 5, the role of nanofluids in the mass transfer operation is discussed. newlineIn Chapter 2, the performance of the hybrid nanofluid of alumina/fly ash-based nanofluid and silica/fly ash-based nanofluid in the direct absorption solar collector is compared. SiO2, Fe2O3, Al2O3, and CaO are the main components of fly ash. The effect of different proportions of major components in fly ash and flow rate on the thermal and exergy efficiency is studied. Micro-channel-based flat plate solar collector is used for the experimentation with a channel height of 800 microns. Experiments are conducted to eva