This paper shows an advanced application of the SPHERA code, a SPH-based numerical model, for simulating the impulsive dynamics of a multiphase system. The final purpose is to set up a numerical model for the development of an innovative technique that could be applied to increase the effectiveness of non-cohesive sediment removal at the bottom of an artificial reservoir through the combined use of submerged micro-explosions and flushing maneuvers. Experimental tests have been carried out to support the study and to provide a data set for model calibration and validation. Since the use of an explosive charge requires special and expensive safety measures, at this stage of investigation micro-explosions are mimed by means of the injection of a cold CO2 pressurized gas from the bottom of a 2D laboratory tank containing water and a sand bed at initial rest condition: even if this represents a strong simplification, the experiments were carried out to provide a first insight in the physics of the water-sediment impulsive dynamics including some similarities with the underwater explosion inside a noncohesive sediment layer at rest (inertial effects dominate). Even if some improvements of the model are required to reach the final purpose, the results show both good qualitative agreement with the experimental frames and the capability of the SPHERA code to support further investigations that are necessary to understand the real feasibility of this removal technique and to optimize the times and locations of injections/explosions in order to improve the efficiency of sediment flushing.

SPH based approach toward the simulation of non-cohesive sediment removal by an innovative technique using a controlled sequence of underwater micro-explosions

MANENTI, SAURO;SIBILLA, STEFANO;GALLATI, MARIO
2015-01-01

Abstract

This paper shows an advanced application of the SPHERA code, a SPH-based numerical model, for simulating the impulsive dynamics of a multiphase system. The final purpose is to set up a numerical model for the development of an innovative technique that could be applied to increase the effectiveness of non-cohesive sediment removal at the bottom of an artificial reservoir through the combined use of submerged micro-explosions and flushing maneuvers. Experimental tests have been carried out to support the study and to provide a data set for model calibration and validation. Since the use of an explosive charge requires special and expensive safety measures, at this stage of investigation micro-explosions are mimed by means of the injection of a cold CO2 pressurized gas from the bottom of a 2D laboratory tank containing water and a sand bed at initial rest condition: even if this represents a strong simplification, the experiments were carried out to provide a first insight in the physics of the water-sediment impulsive dynamics including some similarities with the underwater explosion inside a noncohesive sediment layer at rest (inertial effects dominate). Even if some improvements of the model are required to reach the final purpose, the results show both good qualitative agreement with the experimental frames and the capability of the SPHERA code to support further investigations that are necessary to understand the real feasibility of this removal technique and to optimize the times and locations of injections/explosions in order to improve the efficiency of sediment flushing.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11571/1110827
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