Nano Bubble Lubrication for Flat Plates Skin Friction Reduction

Abstract

The movement of the solution in a pipe is one of the determinants of resistance in the pipe. The resistance occurs due to the solution's movement with the pipe walls in different directions in its displacement. Then, the frictional force is generated due to these differences in movement. This results in an obstacle resulting in high-pressure drop due to a large amount of skin friction. So, in this research, we need a new method to reduce internal resistance in pipes. Before investigating the pipe's internal flow, this study wants to see its function and effect on the flat plate as an attempt to validate the investigations that will be carried out for future research efforts. The study aims to show the lubrication effect produced by using a 50 µm bubble generated by a carbon-ceramic tube. The bubbles' injector distance ratio is 0.4 to 0.85 from the end of the plate. The power needed to produce the bubble is 2.2 kW on a plate with an area of 1x10⁴ mm². The reduction of skin friction was analyzed by capturing the shear stress that was reviewed using a load cell at fluid velocities at intervals of 1 to 20 m.s^-1 with a difference of 1 m.s^-1. The results obtained in this study are that when the fluid velocity is at 7 m.s^-1 to 13 m.s^-1, the distribution of nanobubbles will increase. Moreover, a reduction in drag by + 60.5 percent, and the optimum skin friction (Cv) ratio is at 0.4 to 0.6.