Thermodynamic analysis of fe3o4nanofluid flowing through a circular tube

Abstract

Present work is an experimental study of entropy generation of Fe3O4-water nanofluid flowing through a circular tube. Flow is maintained in the turbulent region and tube is exposed to constant heat flux along the length. Experiments are conducted to study the entropy generation rate for different conditions such as particle volume concentrations varying from 1% to 6% and also for the different Reynolds numbers varying from 6000 to 22000. Measured data from experimentation is taken as input to calculate thermal entropy and frictional entropy generation separately. Based on these thermal entropy and frictional entropy generation total entropy generation and Bejan number are calculated and results are analyzed. Experimentally, it is proved that the changes in the thermal and frictional entropy generations are converse, such a way that, as particle concentration increases entropy generation due to heat transfer decreases whereas entropy generation due to friction increases. Finally experimental results reveal that there exits an optimum particle volume concentration where the total entropy generation is minimal. The same result has also appended by calculating the Bejan number.