Numerical Investigation of Parameters Affecting Energy Losses in Multi-Stage Perforated Plates

Perforated plates are commonly used for flow control in pressurized systems. In different industrial applications, these devices are also used in series (multistage perforated plates) to manage high-pressure drop or reduce cavitation occurrence in industrial pipelines and enhance efficiency of gas turbines in power plants. In some specific conditions, the installation of perforated plates in series is a simple and cost-effective solution that increases plant efficiency. However, the large number of design parameters complicates the search for the optimal solution. With the aim of improving the knowledge of the most relevant design parameters, in the present investigation, the dissipation characteristics of multistage perforated plates are studied. Specifically, the analysis of the dependence of the pressure loss coefficient Eu on relative spacing and hole alignment for two subsequent identical plates is performed with CFD approach. Eight plates with different characteristics such as porosity, thickness, diameter, position, and number of holes are studied. The considered porosities vary in a range of 0.3–0.5, the ratio between plate thickness and hole diameter ranges between 0.7 and 1.3, and the number of holes between 4 and 26. A critical spacing between the plates, beyond which the pressure losses are independent of the alignment of the holes, has been calculated. The results obtained are relevant for a deeper understanding of the complex phenomenon of multistage perforated plates and can be used for the design and the installation of these devices commonly used in different engineering applications.