Based on experimental data, two new trustworthy correlations to predict the dynamic viscosity and thermal conductivity of the nano-lubricant has been proposed. The minimum and maximum enhancement were about 13% and 50%, respectively. The thermal conductivity of the nanofluid showed increasing trend as the solid concentration and temperature increased. Furthermore, the experimental results indicated that the dynamic viscosity of the nano-lubricant increases with an increase in solid concentration while it decreases with an increase in temperature. Based on the measurements, it is found that the studied nano-lubricant showed Newtonian behavior in all the studied temperatures and solid concentrations. First, the effects of temperature and Solid volume fraction on the dynamic viscosity and thermal conductivity of Mg (OH) 2 /MWCNT-engine oil hybrid nano-lubricant have been experimentally investigated. a b s t r a c t The major objective of the present study is to investigate the heat transfer capability of Mg (OH) 2 / MWCNT-engine oil hybrid nano-lubricant. Nanofluid's Heat transfer capability was investigated in different flow regimes. Thermal conductivity increased as the solid concentration and temperature increased. Dynamic viscosity of the nanofluid decreased as temperature increased. Dynamic viscosity of the nanofluid increased as solid concentration increased. The nanofluid showed Newtonian behavior in all the temperatures and concentrations. The results also revealed that the apparent viscosity generally increases with an increase in the solid volume fraction. Moreover, the consistency index and power law index have been obtained by accurate curve fitting for samples with non-Newtonian behavior of nanofluids. The value of maximum enhancement is which occurred in 25 <. The results showed that viscosity has a direct relationship with solid volume fraction of the nanofluid. The measurement results at different shear rates showed that the base fluid and nanofluid samples with solid volume fractions of less than 0.5% had Newtonian behavior, while those with higher solid volume fractions (0.75 and 1%) exhibit a pseudoplastic rheological behavior with a power law index of less than unity. The nanofluid was prepared with solid volume fractions between 0.0625 and 1%, and experiments were performed in the temperature range of 25–50 <. In this paper, experimental investigation of the effects of volume concentration and temperature on dynamic viscosity of the hybrid nanofluid of multi-walled carbon nanotubes and aluminum oxide in a mixture of water (80%) and ethylene-glycol (20%) has been presented. Nanofluids are prepared by suspending the nanoparticles in the base fluid and can be substantially enhanced the heat transfer rate compared to the pure fluids. Investigations showed that maximum value for the margin of deviation for the proposed equation was equal to 8%, which is acceptable for an experimental equation. Due to the lack of a precise and appropriate equation for the prediction of dynamics viscosity of silver/ethylene glycol nanofluid, an equation was provided based on the measurement results, which was a function of volume fraction and temperature. Relative viscosity of the nanofluid increased approximately by 88.46, 90.44, 83.25, and 82.06% by increasing the volume fraction from 0.25 to 2% at 40, 45, 50, and 55 <, respectively. On the other hand, dynamic viscosity of the fluid decreases with increasing temperature. According the results, dynamic viscosity increases with increasing the volume fraction. Dynamics viscosity of nanofluid is measured using the DVI PRIME Brookfield digital viscometer which has a doublewall cylindrical container. In this experiment, the nanofluid was exposed to ultrasound waves for various durations to study the effect of this parameter on dynamic viscosity of the fluid. This experimental study addressed developing a new model for the dynamic viscosity of silver/ethylene glycol nanofluid within the temperature range of 25–55 < for samples with volume fractions of 0.25, 0.5, 0.75, 1, 1.5, and 2%.
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