On the Pressure Losses Through Multistage 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 pipes and enhance efficiency of gas turbines in power plants. Based on analysis of literature and modeling considerations, a functional relationship that describes the dimensionless pressure loss for multistage perforated plates is proposed in this paper. Moreover, numerical investigation of the influence of the spacing between perforated plates for two identical-stage plates with aligned and misaligned holes is carried out by simulating a wide range of Reynolds number in turbulent flow regime. The obtained results include the trend of the pressure loss coefficient as the spacing between the two perforated plates varies for both cases of aligned and misaligned holes. The numerical achievements also show that for small spacing, the pressure loss coefficient is very different from that caused by two independent plates and is strongly influenced by the alignment between the holes of the two plates. By increasing the spacing, the behavior of the losses caused by the two-stage plates tends to that of two independent plates. A critical spacing between the plates has also been defined, beyond which the pressure losses are independent from the alignment of the holes.