Eventos Anais de eventos
ENCIT 2022
19th Brazilian Congress of Thermal Sciences and Engineering
THERMOHYDRAULIC PERFORMANCE OF NANOFLUID FLOW WITH SUDDEN GEOMETRY CHANGE
Submission Author:
Felipe Silva dos Santos , MG , Brazil
Co-Authors:
Felipe Silva dos Santos, ENIO PEDONE BANDARRA FILHO, Mohammad Reza Safaei
Presenter: Felipe Silva dos Santos
doi://10.26678/ABCM.ENCIT2022.CIT22-0142
Abstract
Application of nanofluids in heat transfer enhancement is growing significantly since this new technology is well-suited to heat transfer processes. Several studies on the effect of nanofluids in heat transfer have been conducted to determine the enhancement of properties in addition to rearrangement of flow passage configurations. The main objective of this research is evaluating the performance of nanofluid in single-phase flow with geometry change in heat transfer systems for engineering applications. A test rig was developed to evaluate nanofluids flowing inside tubes focusing on heat transfer and pressure drop. The nanofluids used in the current study, multi-walled carbon nanotube (MWCNT) was produced using the ultrasound as the dispersal mechanism by the two-step method and the measurement of the thermophysical properties (specific mass, viscosity, and thermal conductivity) of the produced nanofluids was also performed. The tests were performed at steady-state condition, and all the inlet parameters were varied: geometry of the test section, inlet temperature in the test section, the flow of the working fluid, supplied heat flux, types of nanofluids, and mass fraction of nanoparticles, etc. At this stage, the experimental data were compared with mathematical models and correlations proposed in the literature to predict thermophysical properties of nanofluids and parameters related to the process of heat transfer by convection. The results indicated that the Reynolds number and the volumetric fraction of nanoparticles affect the heat transfer coefficient considerably; an increase in the local heat transfer coefficient was observed when both the Reynolds number and the volume fractions of nanoparticles are increased for all cases. Therefore, at a constant Reynolds number, the increase in heat flux had no significant influence on the heat transfer and fluid flow parameters.
Keywords
Nanofluid, Heat transfer, Sudden geometry change
