A novel coupled fluid–particle DEM for simulating dense granular slurry dynamics

Proceedings of the Institution of Mechanical Engineers, Part C:

et al. 2021

The self-priming pump is widely used in conveying the solid-liquid two-phase flow medium. The particles in the medium erode the components, leading to structural damage and failure. The computational fluid dynamics (CFD) model of the 65ZW30-20 self-priming pump is built to study erosion characteristics and mechanisms. FLUENT, along with the Discrete Phase Model and Oka erosion model, is applied for the numerical simulation. The particle distribution, impact times and velocity, and trajectories are taken into consideration to investigate the erosion characteristics in each component. The results show that with the increase of the particle concentration, the head and efficiency decreases gradually. The volute wall and blade leading edge are the most vulnerable regions to erosion, because of a large number of impact times and high impact velocity. Also, the particles impact the front gap wall for fewer times and the hub with lower velocity, which leads to a slighter erosion. Besides, the particle trajectories indicate that some particles impact the blade suction surface and the paraxial area of the shroud, rendering considerable erosion.

Section: Erosion Predictionmentioning

confidence: 99%

Effect of particle mass concentration on erosion characteristics of self-priming pump

Zhang

Proceedings of the Institution of Mechanical Engineers, Part C:

et al. 2021

“…At the same time, this manuscript focuses on the soil particle-slurry interaction forces which are mainly drag force. erefore, the Di Felice drag model [11] is selected to calculate the particle-fluid interaction force, and it can consider the interaction among particles by introducing volume fractions of single particle, which is used in other similar studies [12,13]. e Di Felice drag model is shown as follows:…”

Section: Fluid-particle Interaction Forcementioning

confidence: 99%

Study on the Calculation Method of the Diffusion Range of Grouting Slurry for a High‐speed Railway Ballastless Track Subgrade

Advances in Civil Engineering

Guo

Wei

et al. 2021

Grouting engineering is the most convenient and quick way to deal with postconstruction settlement. Based on the investigation of the Beijing Shenyang high-speed railway in the early stage, the microdestructive force of grout on the soil mass in the process of grouting with the method of fluid solid coupling theory was analyzed. The numerical simulation results show that, in the grouting process, the greater the grouting pressure, the wider the diffusion range of the slurry and the greater the damage to the microscopic contact force of the slurry to the soil; in addition, when the grouting pressure is below 0.15 MPa, the diffusion form of the slurry in the soil is osmotic grouting; when the pressure is about 0.3 MPa, the diffusion form of the slurry in the soil is compacted grouting; on the basis of the simulation results, a deeper research is carried out, and the calculation formula of the slurry diffusion curve is obtained. It fills in the blank of the theoretical study of the slurry diffusion curve. In this paper, the diffusion formula of grouting slurry can be used in the theoretical study of clay grouting, and it can be used as a reference for practical engineering.

“…At the same time, this study focuses on the soil particle-slurry interaction forces which are mainly drag forces. erefore, the Di-Felice drag model [24] is selected and used to calculate the particle-fluid interaction force, and it can consider the interaction among particles by introducing volume fractions of a single particle, which is used in other similar studies [25,26]. e Di-Felice drag model is shown as follows:…”

Section: Fluid-particle Interaction Forcementioning

confidence: 99%

Study on Microscopic Roadbed Grouting Mechanism Based on CFD-DEM Coupling Algorithm

Mathematical Problems in Engineering

Guo

Lian³

et al. 2020

Grouting reinforcement technology gradually has been widely used to repair the subgrade settlement diseases, but the current single application of discrete element software or finite element software cannot effectively simulate the grouting process. Therefore, one new method is put forward in the research of grouting based on the CFD-DEM coupling principle. And then, one typical subgrade section in the Shanghai–Nanjing intercity railway is used to simulate the grouting process and diffusion mechanism of slurry from microlevel. Based on the results of site survey, some findings are shown as follows: First, the new method is feasible which integrates the favorable aspects of discrete elements, finite elements, and boundary elements. Second, the greater the grouting pressure, the greater the influence range of grouting, and it shows six petals shape. When the grouting pressure is small, the grouting generally shows penetration or extrusion grouting, and its influence range is small. When the grouting pressure is large enough, it is characterized by splitting grouting, and the influence range of grouting is getting larger and larger. Third, the growth rates of influence range gradually increase with the increasement of grouting pressures, and the reasonable selection of grouting pressures is very important.