Experimental investigation for developing a new model for the dynamic viscosity of silver/ethylene glycol nanofluid at different temperatures and solid volume fractions

This experimental study addressed developing a new model for the dynamic viscosity of silver/ethylene glycol nanofluid within the temperature range of 25–55 °C for samples with volume fractions of 0.25, 0.5, 0.75, 1, 1.5, and 2%. 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. Dynamics viscosity of nanofluid is measured using the DV-I PRIME Brookfield digital viscometer which has a double-wall cylindrical container. According the results, dynamic viscosity increases with increasing the volume fraction. On the other hand, dynamic viscosity of the fluid decreases with increasing 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 °C, respectively. 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. 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.