An Experimental and Numerical Analysis of Water Hammer Phenomenon in Slurries

The analysis of slurry transportation in pressure pipelines is important both from practical and theoretical point of view. Due to the nature of the medium, the number of problems arising in the course of design, operation, measurements and mathematical modeling is much higher compared to the cases where the flowing liquid is homogeneous. The equations describing the flow are more complex, and higher number of the parameters is required to express the behavior of the system. The problem becomes even more complicated when specific unsteady phenomena are described. One of such cases is water hammer in slurries. In this paper, the experimental and numerical analyses of transient flow of slurries in HDPE pipeline are presented. The experiments were carried out for the slurries of different densities in the water stream. For this purpose, the laboratory model, enabling the measurements of pressure characteristics caused by the rapid valve closure, was constructed. Based on the experimental results, the numerical model for slurry transient flow was developed. The impact of the slurry density and the presence of the solid bottom layer on transient flow characteristics has been taken into account by the equivalent density factor. Comparison of the numerical simulations with the experimental results indicated that the introduction of this parameter into the equations describing the transient flow significantly improves calculations. It enables the successful and effective application of the relatively simple mathematical model which leads to a very good agreement with measurements.