Experimental study of transient pressures generated by the impact of a liquid-liquid system

The failure of a structure, either hydraulic or coastal, may be caused by pressure propagation and distribution generated by a fluid impact, that produces uplift pressure. The mechanics of wave impacts are still not properly understood and is a complicated problem, mainly due to the fact that the water interacts with the surrounding air and the air is more compressible than water. The objective of this work was to understand the behaviour of a pressure pulse, generated by a liquid– liquid impact, propagating by a two-phase flow. An experimental facility was constructed, consisting of an upper reservoir and a lower chamber attached to a horizontal steel pipe equipped with pressure transducers. The facility enabled the impact of two masses of water and the propagation of a pressure pulse along the horizontal pipe. The impact generated pressure transients of high intensity. The presence of air in the mixture influenced the duration of the transient and decreased peak pressures.