Modeling of Surfactant Influence on Liquid Velocity in the Channel of the Focusing Tube of the Nozzle of a Waterjet Unit

The paper presents the results of modeling the changes in the velocity of fluid flow in the channel of the focusing tube of a waterjet unit when injecting surface-active additives (surfactants) that affect the reduction of turbulent friction and hydraulic resistance. The authors of the article proposed a mathematical model of shear flow of various liquids along a solid wall, confirmed by experiment. Fluent software was used to model the fluid flow of modified surfactant in the channel of the focusing tube of the waterjet. The main approach for modeling was to solve the Navier-Stokes equations using the method of control volumes. The simulation results show that the highest flow velocity is observed at the inlet of the focusing tube, and the flow velocity gradually decreases along the axis of the tube and reaches the minimum velocity at the outlet. An increase in the liquid flow velocity in the focusing tube by 15% is observed due to the reduction of turbulent friction when surfactant is injected.