Simulation Modeling of the Combined Damage Caused by Cavitation and Abrasion in Sediment-Laden Liquids

Abstract

Combined damage caused by cavitation and abrasion is a serious problem concerning hydraulic structures and machinery operating in hyper-concentrated sediment-laden rivers. Conceptualization of a model for simulation and assessment of the combined damage, therefore, becomes necessary. Experimental results demonstrate that sediments cast a strong influence on the combined damage caused by cavitation and abrasion. Sediments with size larger compared to a critical size tend to aggravate the combined damage, while sediments with size smaller compared to critical relieve the combined damage effect when compared against cavitation-only damage. Based on these results, a new model has been proposed and built in order to predict the combined damage and assess the range of sediments that relieve or aggravate the damage as sediments pass through the structure and machinery. The model represents an integral with damage as the integrand and sediments representing the domain of integration, and was built in three steps—the first step establishes a relationship between damage and sediments of a single size (SS model); the second step establishes a relationship between damage and sediments from an actual river (MS model); and the third step proposes a standard to assess the damaging effect on hydro machinery (CS model). Model parameters were verified using 74 cases of laboratory experiments. By comparing simulation results against experimental data, it has been inferred that the proposed model can be employed to study practical problems in a predictive manner and promote safe operation of reservoirs by predicting damage characteristics of river water.