Simulation of Fluid Flow in A U-Shape Self-Siphon and Its Working Space

Observation of occurrence of fluid flow in a U-shape self-siphon has been conducted experimentally and in simulation. Water is chosen as the fluid. in experiment, three kinds of pipe inner diameter d (4, 6, and 8 mm) have been used to find its influence to the flow occurrence. The U-shape self-siphon has three different segments, where length of the first segment plays important role for the flow occurrence. The segment has length L + h, which stands for length above and below water surface in water container, respectively. In simulation, head (interface between water and air in the siphon) equation of motion is solved numerically using Euler method. Working spaces of L against h for several d have been produced from simulation and experiment, and they show a good agreement to each other. It can be observed that the relation between L and minimum h for flow to occur becomes more linear for larger inner diameter d.