Numerical Simulation and Experimental Validation of Three-Dimensional Unsteady Multi-Phase Flow in Flushing Process of Toilets

2013 ◽  
Vol 444-445 ◽  
pp. 304-311 ◽  
Author(s):  
Jian Guo Hu ◽  
You Song Sun ◽  
Zheng Rong Zhang
Keyword(s):  
Numerical Simulation ◽  
Three Dimensional ◽  
High Viscosity ◽  
Coupling Scheme ◽  
Phase Flow ◽  
Two Phase ◽  
Discrete Equations ◽  
Vof Model ◽  
Multi Phase Flow ◽  
Multi Phase

In order to predict the flush performances of digital toilet products before mass production, a numerical simulation for a three-dimensional unsteady multi-phase flow in the flushing process of a wash-down toilet is carried out by using FLUENT software. The finite volume method (FVM) is used to discrete the three governing equations in space and time. The discrete equations are solved by using the first-order upwind discretization scheme and the PISO pressure-velocity coupling scheme. The realizable turbulence model is chosen as the viscous model to treat the fluid flow with large bending curvature wall. The volume of fluid (VOF) model is applied to solve the transient free-surface problem. First, a two-phase flow was simulated on the assumption that there is not sewage but water in the trap seal. Then, by simplifying the mixture of sewage and water in the trap seal as the third phase with high viscosity, a three-phase flow was simulated. Moreover, in order to validate the simulated results, a flushing testing was conducted to test the flush range, and a target type flow meter was designed, calibrated and applied to test the flush velocity. The comparisons show a good agreement between the numerical and experimental results. Based on the verified simulation results, the flush performances of the digital wash-down toilet, such as flush range, flush velocity and sewage replacement ability, can be predicted and evaluated.

A Similarity Solution for Imbibition Process and its Adaptation in Finite Difference Simulation of Fractured Reservoirs

2021 ◽  
Author(s):  
Song Du ◽  
Seong Lee ◽  
Xian-Huan Wen ◽  
Yalchin Efendiev
Keyword(s):  
Numerical Simulation ◽  
Finite Difference ◽  
Similarity Solution ◽  
Capillary Force ◽  
Fractured Reservoirs ◽  
Phase Flow ◽  
Scale Modeling ◽  
Fracture Models ◽  
Multi Phase Flow ◽  
Multi Phase

Abstract The imbibition process due to capillary force is an important mechanism that controls fluid flow between the two domains, matrix and fracture, in naturally or hydraulically fractured reservoirs. Many simulation studies have been done in the past decades to understand the multi-phase flow in the tight and shale formation. Although significant advances have been made in large-scale modeling for both unconventional and conventional fields, the imbibition processes in the fractured reservoirs remains underestimated in numerical simulation, that limits confidence in long-term field production predictions. In the meanwhile, to simulate the near-fracture imbibition process, traditionally very-fine simulation grids have to be applied so that the physical phenomena of small-length scale could be captured. However, this leads to expensive computation cost to simulate full-field models with a large number of fractures. To improve numerical efficiency in field-scale modeling, we propose a similarity solution for the imbibition process that can be incorporated into the traditional finite difference formulation with coarse grid cells. The semi-analytical similarity solutions are validated by comparing with numerical simulation results with fine-scale grids. The comparison clearly indicates that the proposed algorithm accurately represents the flow behaviors in complex fracture models. Furthermore, we adopt the semi-analytical study to hydraulic fracture models using Embedded Discrete Fracture Model (Lee et al., 2001) in our numerical studies at different scales to represent hydraulic fractures that are interconnected. We demonstrate: 1) the imbibition is critical in determining flow behavior in a capillary force dominant model, 2) conventional EDFM has its limitation in capturing sub-cell flow behaviors near fractures, 3) combining the proposed similarity solution and EDFM, we can accurately represent the multi-phase flow near fractures with coarser grids, and 4) it is straightforward to adapt the similarity solution concept in finite-difference simulations for fractured reservoirs

Two-Phase Flow Field Numerical Simulation in Scrubber for Exhaust Gas Desulfurization

2014 ◽  
Vol 541-542 ◽  
pp. 1288-1291
Author(s):  
Zhi Feng Dong ◽  
Quan Jin Kuang ◽  
Yong Zheng Gu ◽  
Rong Yao ◽  
Hong Wei Wang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Flue Gas ◽  
Two Phase Flow ◽  
Three Dimensional ◽  
Flue Gas Desulfurization ◽  
Parameter Design ◽  
Phase Flow ◽  
Two Phase ◽  
Entrance Angle

Calculation fluid dynamics software Fluent was used to conduct three-dimensional numerical simulation on gas-liquid two-phase flow field in a wet flue gas desulfurization scrubber. The k-ε model and SIMPLE computing were adopted in the analysis. The numerical simulation results show that the different gas entrance angles lead to internal changes of gas-liquid two-phase flow field, which provides references for reasonable parameter design of entrance angle in the scrubber.

The Research on Steering Fracture Numerical Simulation

2013 ◽  
Vol 734-737 ◽  
pp. 1488-1492
Author(s):  
Zhen Yu Liu ◽  
Li Hong Yao ◽  
Hu Zhen Wang ◽  
Cui Cui Ye
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Three Dimensional ◽  
Simulation Method ◽  
Production Performance ◽  
Phase Flow ◽  
Water Production ◽  
Two Phase ◽  
Fractured Well

The fractures after artificial steering fracturing appear in shades of curved surface. Aiming at the problem of steering fracture, in the paper, numerical simulation method under the condition of three-dimensional two-phase flow is presented based on finite element method. In this method, of steering fracture was achieved by adopting surface elements fractures and tetrahedron elements to describe formation. By numerical simulation, the change rule of oil and water production performance of steering fractures can be calculated, and then the steering fracture parameters can be optimized before fracturing. A new method was supplied for the numerical simulation of artificial fractured well.

Numerical Simulation of Multi-Phase Flow Distribution in Parallel Pipelines System of Oil Transfer Station

2019 ◽  
Author(s):  
Yingying Wang ◽  
Chunsheng Wang ◽  
Qiji Sun ◽  
Yuling Lv
Keyword(s):  
Numerical Simulation ◽  
Branch Pipe ◽  
Flow Distribution ◽  
Simulation Models ◽  
Phase Flow ◽  
Gas Oil ◽  
Inlet Flow ◽  
Multi Phase Flow ◽  
Oil Water ◽  
Multi Phase

Abstract The mal-distribution of gas-oil-water multi-phase flow in parallel petroleum processing pipelines can directly affect the working condition of the separators. In this paper, the influence of different factors on the flow distribution and the characteristics of gas-oil-water distribution in parallel pipelines was investigated by three-dimensional CFD numerical simulation. Firstly, four different simulation models are established based on different arrangement types of parallel pipelines. The simulation results show that the distribution of gas-oil-water flow in the radial entry symmetrical two-stage pipe-laying simulation model was the most uniform among the four simulation models. Then, four radial entry symmetrical two-stage pipe-laying simulation models with different distance between branch pipes were establish. From the simulated results, it can be found that the distance has no effect on the distribution of gas-oil-water flow in each branch pipe, but great influence on distribution of flow rate in each branch pipe. Finally, the influence of the inlet flow characters on the flow distribution is investigated. It can be found that the “bias flow” phenomenon of the parallel pipelines decreasing with the increase of the inlet flow velocity, the gas content of inlet flow and the water content of inlet liquid.

The Study of Electrode Size on Sensitive Field Effect of Electromagnetic Flow Meter in the Measuring Fluids Containing Non-Conductive Body

2013 ◽  
Vol 756-759 ◽  
pp. 551-555
Author(s):  
Yue Ming Wang ◽  
Ling Fu Kong ◽  
Ying Wei Li
Keyword(s):  
Phase Flow ◽  
Flow Meter ◽  
Two Phase ◽  
Electrode Size ◽  
Electromagnetic Flow ◽  
Response Characteristics ◽  
Conductive Body ◽  
Multi Phase Flow ◽  
Electromagnetic Flow Meter ◽  
Multi Phase

Electromagnetic flow meters are widely used in two-phase or multi-phase flow measurements in recent years. In this paper, simulation model is established to study the flow meter response characteristics which exist a non-conductive body (oil bubble) in the fluid by use finite element software ANSYS. We analyze different electrode size impact on the response characteristics of electromagnetic flow meter in the measurement of two-phase or multi-phase flow which includes non-conductive material in the fluid, which provides reference for design of the sensor electrode sizes, and provides a theoretical basis for error analysis measuring two-phase or multi-phase flow under different electrode sizes of electromagnetic flowmeter.

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