Influence of grooved volute casing parameters on pressure pulsation and erosion wear characteristics in a centrifugal pump

Previous work has shown that performance and internal flow characteristics of a centrifugal pump can be significantly improved with grooved volute casing (GVC). However, it has been found that the selection of the design parameters of the groove structure also has a direct impact on the performance output, internal flow pressure pulsation and erosion wear characteristics of the overflow components of centrifugal pump, so it is necessary to further analyze the design rules of the groove structure parameters. In this study, we first investigated the influence of the number of grooves on the head, efficiency and unsteady pressure pulsation characteristics of the internal flow field of the centrifugal pump, and on this basis, the correlation between different particle parameters and the erosion wear of key overflow components under the conditions of solid–liquid two-phase flow were also studied, and the erosion wear characteristics of the inner wall of the volute casing of centrifugal pump with GVC and original volute casing (OVC) structures were compared. This research leads to the conclusion that when the number of grooves is 3, the groove structure has the least influence on the performance of the centrifugal pump, and the overall change of the performance curve is more stable. Additionally, the pressure pulsation at each monitoring point of the GVC under the same flow condition is smaller, and when the number of grooves increases, the pressure pulsation amplitude also decreases. When the number of grooves is 3, the GVC shows a more significant flow improvement effect under all flow conditions. Based on the improvement of the groove structure on the flow stability, the particle motion behavior can be affected at the same time, so that the pump with GVC can mitigate the erosion wear of the inner wall of the volute casing under the solid–liquid two-phase flow conditions, which improves the critical performance and service life of the key overflow components of the pump.

CFD modeling of slurry flow erosion wear rate through mitre pipe bend

Erosive wear caused by particulates slurry is one of the major concerns in the pipe bend which may results in the failure of the pipe flow system. In the present work, erosion wear rate through mitre pipe bend caused by silica sand particulates slurry has been investigated using ANSYS Fluent code. The solid spherical particulates of size 125 µm and 250 µm having density of 2650 Kg/m3, were tracked to compute the erosion wear rate using Discrete Phase Method (DPM) model. The particulates were tracked using Eulerian-Lagrange approach along with k-ɛ turbulent model for continuous fluid phase. The silica particulates were injected at solid concentration of 5% and 10% (by weight) from the pipe inlet surface for wide range of velocities viz. 1–8 ms−1. The erosion wear rate was computed through four computational erosion models viz. Generic, Oka, Finnie and Mclaury. Furthermore, the outcomes obtained through Generic models are verified through existing experimental data in the literture. Moreover, the results of DPM concentration, turbulence intensity and particle tracking were predicted to analyze the secondary flow behaviour through the bend cross section. Finally, the effect of particulate size, solid concentration and flow velocity were discussed on erosion wear rate through bend cross section. The findings show that the locality of maximum erosive wear is positioned at the extrados of the bend outlet cross section. Additionally, it is found that Mclaury model offers higher erosion rate as compared to the other models and provides benchmark for designing the slurry pipeline system.

Design Optimization of a Helical Coil Gas Cooler Based on the Results of CFD Modeling of Erosion Wear

Simulation of erosion wear and design optimization have been performed for a convective gas cooler with a helical coil. Based on the results of simulation of the standard gas cooler design with a flat baffle used in Shell gasification-based combined cycle unit, it is concluded that the particle impact angle is the main factor determining the erosion maximum. To reduce erosion, it is necessary to install a structural element instead of the flat baffle to align the flow path of ash particles at the inlet to the gas cooler. The results of simulation for various baffle shapes show that a hemispherical baffle is optimal. The use of a hemispherical baffle plate made it possible to align the ash particle flow path at the inlet to the gas cooler channels and reduce the maximum level of erosion by a factor of almost 4 compared to the standard geometry of the baffle plate.

Effect of erosive parameters on solid particle erosion of cotton fiber–based nonwoven mat/wooden dust reinforced hybrid polymer composites

Abrasive particle-induced erosive wear of polymeric engineering components is a major industrial issue. The research of solid particle erosion characteristics of polymeric composites becomes essential due to operational needs in dusty conditions. Nonwovens are now employed in industrial applications for polymeric composites. Nonwoven products are made from a wide range of raw materials, ranging from synthetic to natural fibers. This work finding the effect of nonwoven cotton fiber (5, 10, and 15 wt.%) loading on the physical, mechanical, and erosion wear of fixed wooden dust (4 wt.%) filled hybrid epoxy composites. Experimental results reveal improved impact strength, hardness, and compressive and tensile strength with an increment of fiber loading from 5–15 wt.%. The density of the composites was found to increase, whereas void content decreases with an increase in cotton fiber. The erosion wear of the composites has been studied using an L27 orthogonal array to assess the effects of various parameters such as fiber loading, erodent size, impact velocity, impingement angle, and stand-off distance. The erosion wear increased with impact velocity and remained highest for 60° of impingement angle. The most significant parameter affecting the erosion wear was determined as impact velocity followed by impingement angle. Surface morphologies of eroded samples reveal the fiber pull-out, and fiber breakage was the prominent phenomenon for the erosion wear of the evaluated composites.

Numerical Analysis of Erosion Wear of Water with Particles in Elbows

In this paper, the numerical analysis of erosion wear of water with particles in elbow is carried out based on fluent. The influence of different inlet velocity and bending angle on pipeline erosion, and the distribution of pressure field and velocity field in the pipeline are studied. The main conclusions are as follows: the erosion of elbow section is more serious than that of inlet section and outlet section of pipeline. With the increase of inlet velocity, the maximum erosion rate of elbow section gradually increases, and the maximum velocity and maximum pressure inside the elbow section also increase. When other conditions are certain, different bending angles make the elbow receive different erosion effects. When the bending angle is larger, the pipeline erosion rate is relatively more uniform. Study on erosion helps to reduce the impact of fluid on the wall and improve the safety and reliability of engineering.