Simulation of flow field and sludge settling in a full-scale oxidation ditch by using a two-phase flow CFD model

2014 ◽  
Vol 109 ◽  
pp. 296-305 ◽  
Author(s):  
Hao Xie ◽  
Jiakuan Yang ◽  
Yuchen Hu ◽  
Hao Zhang ◽  
Yin Yang ◽  
...  
2004 ◽  
Author(s):  
Gary Luke ◽  
Mark Eagar ◽  
Michael Sears ◽  
Scott Felt ◽  
Bob Prozan

2014 ◽  
Vol 541-542 ◽  
pp. 1288-1291
Author(s):  
Zhi Feng Dong ◽  
Quan Jin Kuang ◽  
Yong Zheng Gu ◽  
Rong Yao ◽  
Hong Wei Wang

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.


Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2506 ◽  
Author(s):  
Yuquan Zhang ◽  
Chengyi Li ◽  
Yanhe Xu ◽  
Qinghong Tang ◽  
Yuan Zheng ◽  
...  

The oxidation ditch (OD) plays an important role in wastewater treatment plants. With increasing demand and production costs, the energy consumption and sludge deposition occurring in the OD must be diminished to enhance its development. In this paper, a two-phase computational fluid dynamics (CFD) model of water and activated sludge examined the flow field characteristics of an OD, consisting of two side-by-side propellers. The system was studied under five configurations, where the spacing between the propellers was set equal to −0.2, −0.1, 0, 0.1, 0.2 times the length of the OD. The viscosity and settling rate of activated sludge was imported in the numerical simulation through a user defined function (UDF). The optimal scheme of the propeller’s power consumption, velocity distribution, and sludge concentration distribution was obtained. The result shows that sludge concentrations are linked with dead zone velocity but not necessarily with low velocities. Experiments confirmed the validity of the velocity flow field simulated by the two-phase CFD model. Overall, these findings form the basis for the propellers distribution optimization and allow a deeper insight into the flow field of OD systems.


2011 ◽  
Vol 418-420 ◽  
pp. 2006-2011
Author(s):  
Rui Zhang ◽  
Cheng Jian Sun ◽  
Yue Wang

CFD simulation and PIV test technology provide effective solution for revealing the complex flow of hydrodynamic coupling’s internal flow field. Some articles reported that the combination of CFD simulation and PIV test can be used for analyzing the internal flow field of coupling, and such analysis focuses on one-phase flow. However, most internal flow field of coupling are gas-fluid two-phase flow under the real operation conditions. In order to reflect the gas-fluid two-phase flow of coupling objectively, CFD three-dimensional numerical simulation is conducted under two typical operation conditions. In addition, modern two-dimensional PIV technology is used to test the two-phase flow. This method of combining experiments and simulation presents the characteristics of the flow field when charging ratios are different.


2011 ◽  
Vol 130-134 ◽  
pp. 3644-3647
Author(s):  
Ding Feng ◽  
Si Huang ◽  
Yu Hui Guan ◽  
Wei Guo Ma

This work performs an oil-water two-phase flow simulation in a downhole Venturi meter to investigate the flow field and pressure characteristics with different flow and oil-water ratios. The relation between the pressure drop and the feed flow rate in the flowmeter is investigated for its optimal design.


2014 ◽  
Vol 2014 ◽  
pp. 1-19 ◽  
Author(s):  
Jorge Pérez Mañes ◽  
Victor Hugo Sánchez Espinoza ◽  
Sergio Chiva Vicent ◽  
Michael Böttcher ◽  
Robert Stieglitz

This paper deals with the validation of the two-phase flow models of the CFD code NEPTUNEC-CFD using experimental data provided by the OECD BWR BFBT and PSBT Benchmark. Since the two-phase models of CFD codes are extensively being improved, the validation is a key step for the acceptability of such codes. The validation work is performed in the frame of the European NURISP Project and it was focused on the steady state and transient void fraction tests. The influence of different NEPTUNE-CFD model parameters on the void fraction prediction is investigated and discussed in detail. Due to the coupling of heat conduction solver SYRTHES with NEPTUNE-CFD, the description of the coupled fluid dynamics and heat transfer between the fuel rod and the fluid is improved significantly. The averaged void fraction predicted by NEPTUNE-CFD for selected PSBT and BFBT tests is in good agreement with the experimental data. Finally, areas for future improvements of the NEPTUNE-CFD code were identified, too.


2013 ◽  
Vol 712-715 ◽  
pp. 1253-1258
Author(s):  
Hai Feng Xue ◽  
Xiong Chen ◽  
Yong Ping Wang ◽  
Ya Zheng

The two-dimension axisymmetric and two-phase flow in a full-size solid rocket motor with submerged nozzle under high acceleration condition has been simulated with Euler-Lagrange model. Without acceleration and under high axial acceleration on particle trajectories, the influences of different particle diameters were analyzed. The difference between gas flow field and two-phase flow field is significant. The particle accumulation zone above the inner wall of chamber and nozzle is mainly concentrated in two regions. The axial acceleration will intensify the impaction to the end of the chamber. The accretion of the particle phase diameter will increase the inertia of the particle phase, which may cause the following property worse, and the particles can easily form a highly-concentrated aggregation flow.


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