Investigating the effect of Velocity on Water Column Separation using CFD Methods

The Water Column Separation phenomenon is one of the transient flow regimes, which is created under conditions such as the sudden closing of the valve or the shutdown of the pump in the water supply network. Hard pressure fluctuations and damages caused by the mentioned phenomenon require identifying and providing a solution to prevent it. By this purpose, the present article investigates the possibility of Water Column Separation in a Loop Water Supply Network using Computational Fluid Dynamics method. Next, the Effect of the inlet velocity on the pressures created due to the Water Column Separation was investigated. For software validation, the Loop system provided by Wang et al. (2017) was selected. After ensuring the efficiency of the software to model the phenomenon of Water Column Separation, simulation was performed at different speeds. Checking the simulation results indicated the occurrence of Water Column Separation in the Intended Network. Also, the Results indicated that with the increase of the input Velocity, the maximum value of the Pressure in the Network increases and its minimum value decreases. In such a way that with a 12% increase in the input velocity, the maximum pressure value changes by 11.8% and the minimum value by 14.26%. In general, it can be said that by controlling the Velocity as an effective factor on the pressure fluctuations of the Water Column Separation, this phenomenon and the resulting damages are prevented.