The Effect of SiO2 Nanoparticles on the Performance of a Centrifugal Pump with Superhydrophilic and Superhydrophobic Blades: An Experimental Study

Improving the performance of turbopumps has been one of the main concerns of researchers in mechanical engineering. In this study, we have tried to investigate the effect of SiO2 nanoparticles on the performance of a pump with superhydrophobic and superhydrophilic impeller blades. In this process, we used a pump with aluminum blades with a nominal flow of 11 LPM and a nominal head of 5 m. To investigate the effect of nanoparticles, we used water–SiO2 nanofluid with a particle diameter of 15–20 nm and 0.5% volumetric concentration at 25 ℃ temperature. Moreover, the pump impeller has become superhydrophilic and superhydrophobic using surface engineering technology. To perform the experimental study, we ran the test in five cases, the combinations of the two mentioned fluids and the three mentioned blades form. Results show that when the pure water was used with the superhydrophilic blades, the head of the pump was dropped, which negatively affected the pump's performance. However, using the nanofluid and superhydrophilic blades simultaneously improved the pump's performance and increased the pump's head. We also analyzed the cavitation of the pump. We have used the net positive suction head (NPSH) method for this target. We have reached a result that, compared to tap water with uncoated blades, NPSH of the cases SiO2–water nanofluid with uncoated blades, tap water with superhydrophilic blades, tap water with superhydrophobic blades, and SiO2–water nanofluid with superhydrophilic blades have decreased 4, 7, 7, and 12%, respectively. This means that using nanofluid and superhydrophilic blades simultaneously can delay the cavitation initiation significantly.