Cavitation Characteristics of Shutoff Valves in Numerical Modeling of Transients in Pipelines with Column Separation

Abstract

The paper presents the results of calculations of the water-hammer course accompanied by the column separation caused by a rapid closure of the inline valve. The most important problem which the paper is dealing with is taking into account the cavitation characteristics of the inline valve. The calculation method contains a special way of including valve characteristics that have been determined on the laboratory setup in the Szewalski Institute of Fluid-Flow Machinery (IFFM) in Gdansk, Poland. In addition, calculations have been conducted using the writers’ own discrete vapor cavity model (DVCM), the new single-zone DVCM. The paper presents a comparison between these calculation results and the experimental results obtained at the laboratory setup for investigation of the water-hammer phenomenon in the pump discharge pipeline. The comparison of the numerical and empirical results is a basis for the verification process and assessment of the computational method that has been developed. The results and conclusions presented in this paper are of great importance from the theoretical and practical point of view, and thus give the basis for better understanding of the pipeline transients accompanied by the column separation phenomenon.