Banca de QUALIFICAÇÃO: BRENO CAMARA CAVALCANTI

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : BRENO CAMARA CAVALCANTI
DATE: 19/10/2020
TIME: 14:00
LOCAL: google meets
TITLE:

Preparation of nanolubricant POE/CuO/Graphene Oxide for use in refrigeration systems.

KEY WORDS:

nanolubricant, refrigeration, copper oxide, graphene oxide

PAGES: 83
BIG AREA: Engenharias
AREA: Engenharia Mecânica
SUBÁREA: Engenharia Térmica
SUMMARY:

Nanofluids, in a generic way, consist of a biphasic mixture of solid particles of nanometric dimensions dispersed in a base fluid. In the literature, a variety of nanoparticles have been used to investigate the ability to improve the tribological and thermal properties of lubricants, obtaining potentially interesting results. This work has as main objective the synthesis of a hybrid nanolubricant from graphene oxide (OG) and copper (CuO) nanoparticles in the proportion of 1: 1 and concentrations of 0.05; 0.1 and 0.2% by weight dispersed in commercial polyolester synthetic oil. The samples are subjected to an ultrasonic bath for 60 minutes and their stability is verified by observing the sedimentation of the nanoparticles. 6.7 ml samples of nanofluids are used to perform dynamic viscosity test on the Brookfield DV-III + apparatus in temperature range of 10 to 60°C. Tribological performance is evaluated using the High Frequency Reciprocating Rig (HFRR) ball (AISI 52100) on disc (cast iron FC-200) test @50°C, obtaining values for coefficient of friction (COF), lubricating film formation and wear scar diameter (WSD) of the ball. The coefficient of thermal conductivity (k) is measured using the KD2 PRO equipment by transient line heat source method @ 25°C. A refrigeration system apparatus with temperature and pressure monitoring is used to calculate coefficient of performance (COP) of thermodynamic cicle that uses nanofluid as lubricant. In comparison with the pure base oil, there was minimal variation in the dynamic viscosity with an increasing tendency for higher concentrations of nanoparticles, reduction of up to 24% in WSD and 15% in COF as well as a small increase of up to 2% for k.

BANKING MEMBERS:
Interna - 1481705 - SALETE MARTINS ALVES
Externo ao Programa - 349577 - CLEITON RUBENS FORMIGA BARBOSA
Externo ao Programa - 2654020 - KLEIBER LIMA DE BESSA