Study on the dynamic characteristics of sand-laden suction vortex in the hydraulic machinery based on experimental test Available to Purchase

Sediment-laden surface vortices in pump sump represent a three-phase flow, comprising gas, liquid, and solid phases, surpassing the complexity of clear water vortices, which has also more serious effect on the hydraulic machinery. In this paper, focusing on sediment-laden free surface vortices, a model experiment was employed to investigate their motion characteristics. The spatiotemporal evolution of sediment-laden vortices has been captured through three-dimensional velocity testing, revealing particle aggregation and dispersion patterns within vortex cores at various stages. Radial velocity within the vortex core accelerates the inward movement of particles, while axial velocity enhances their vertical transport. The scale of sandy vortices is larger than that of clear water vortices, approximately 1.2 times the size, and the rotational velocity within the vortex core is lower for sandy vortices, with maximum rotational velocities of 1.04 and 0.5 m/s, respectively. The maximum suction speed of the vortex is 6.1 times that of the initial stage, and the sediment-carrying capacity is 21 times greater. Finally, the mechanism and characteristics of vortex transporting sand and air are discussed, along with the detrimental effects of various sediment-carrying vortices on the sediment erosion of hydraulic machinery. The research findings of this paper have significant theoretical and engineering values.