Study on Installation Position of Sewage Treatment Mixer

Author(s):  
Fei Tian ◽  
Wei-dong Shi ◽  
Bin Chen ◽  
Wei-dong Cao

According to the problem that how to choose the installation position for sewage treatment mixer was uncertain, the flow field in the sewage treatment pool was simulated by the software FLUENT 6.3, using unstructured tetrahedral grid, moving coordinate system technology, k ∼ ε turbulence model and the SIMPLE algorithm. The distribution of velocity gradient in the whole pool was analyzed, and the flow field was compared at the different installation angles of sewage treatment mixer. The results show that the fluid flows along the axial direction of sewage treatment mixer, and diffuses along the radial direction. The stirring circulation is evident when the installation deviates from the narrow side, and the flow velocity of the whole pool is relatively uniform and greater than 0.3m/s. It is consistent with their work requirements, which not only improves the efficiency, but also saves costs.

2013 ◽  
Vol 416-417 ◽  
pp. 428-432
Author(s):  
Li Shan ◽  
Xiao Wei Cheng ◽  
Yong Fang ◽  
Xiao Hua Bao

This paper investigates the vibration which caused by electromagnetic on the stator end-winding of the large dry submersible motor. Firstly, the electromagnetic field which included transition state and steady state is researched by 3-D FEM. Secondly, the electromagnetic force which lead to vibrations of end-winding is calculated by numerical method, it can be obtained that where endured the largest force density along the slant part of end-winding. Finally, the radial displacement and the axial displacement of the slant part which caused by vibrations is studied, the analysis results show that the axial displacement is larger than the amplitude of radial displacement. It indicates that the slant part of end-winding will be more easily damaged at axial direction than radial direction.


Author(s):  
Mou-jin Zhang ◽  
Chuan-gang Gu ◽  
Yong-miao Miao

The complex three-dimensional flow field in a centrifugal impeller with low speed is studied in this paper. Coupled with high–Reynolds–number k–ε turbulence model, the fully three–dimensional Reynolds averaged Navier–Stokes equations are solved. The Semi–Implicit Method for Pressure–Linked Equations (SIMPLE) algorithm is used. And the non–staggered grid arrangement is also used. The computed results are compared with the available experimental data. The comparison shows good agreement.


2014 ◽  
Vol 1006-1007 ◽  
pp. 990-993
Author(s):  
An Ling Wang ◽  
Fu Ping Liu

Because difference of formation model affects the potential distribution on the metal casing, the resistivity logging response can be obtained through casing by measuring the potentials on the metal casing. In fact, the logging responses are the comprehension effects of complex formation and metal casing, so that in the coefficients of transmission line equation (TLE), we should consider the effects of formation model in radial-direction. In the following, for the formation taking on six-layer in axial-direction, and step in radial-direction, the resistivity logging responses through casing are researched and discussed, and given the recurrence formula to compute potential. Draw the curve of the resistivity logging response through casing of six-layer formations. The conductivity of formation is computed is very approximating to that of formation model. The computing examples also show that this method has a fast computing speed (the run time of computing example is less than 1s). For analysis the logging response of six-layers and block formations, and the design of logging instruments, the research is important significance and useful.


2013 ◽  
Vol 820 ◽  
pp. 225-228
Author(s):  
Tong Li ◽  
Jing Tao Wei ◽  
Ji Li

It is difficult to sort fine non-magnetic particles only by the buoyancy of magnetic fluid. Therefore, based on the magneto hydrostatic separation, the centrifugal separation under the condition of centrifugal force would be an effective method to improve the efficiency. By establishing the mechanical model of centrifugal separation in magnetic fluid, this paper analyzes the kinematical equations of non-magnetic particles in three directionstangential direction, radial direction, and axial direction, and then theoretically explores the separation mechanism of this method.


2010 ◽  
Vol 139-141 ◽  
pp. 1048-1051 ◽  
Author(s):  
Qin Li ◽  
Hui Lin Wang ◽  
Fu Bao Li

The pressure distributions in cavitations nozzle of three different structures were studied by Hydromechanics theory, the models and mashes were completed by using Gambit software, for the conditions of the inlet pressure to 20MPa and the outlet pressure to 0.1MPa, the flow field within cavitations nozzles is simulated based on the standard k-ε model and the SIMPLE algorithm with Fluent. The result of numerical simulation is consistent with that of analytical calculation. Simulation results show that the flow has a strong shear effect with the surrounding medium in the diffuser, resulting in significant negative pressure, which is conducive to the formation of cavitations bubbles. The angle nozzle is best selected for impinging streams cavitations reactor on this basis in the paper.


2011 ◽  
Vol 383-390 ◽  
pp. 25-31
Author(s):  
Wei Xing Xu ◽  
Ming Yue Fan

The impeller of submersible mixer in some sewage treatment plant, whose parts are imported from other countries, is heavily abased. To solve this problem and realize domestic manufacture, based on reverse engineering theory, utilizing 3 coordinates measuring machine and applications of Surface and Pro/E, 3D solid model of impeller are gained. The gained impeller model accords with the physical one with high accuracy. The flow formulation is founded as console formulation first, and with the body-fitted coordinate system and standard turbulent model, the numerical simulation of the internal 3-D incompressible turbulent flow agitated flow field of submersible mixer is carried out by numerical simulation software Fluent. The results showed that: the mixer impeller produced vortex jet flow, the constant velocity lines advanced as ellipse, the velocity along the centerline are larger than others, and utilized volume flow to transport the liquid.


1995 ◽  
Vol 09 (16) ◽  
pp. 1033-1037
Author(s):  
M. ZAKAULLAH ◽  
IMTIAZ AHMAD ◽  
KHAIRUR REHMAN ◽  
G. MURTAZA

The CR-39 solid state nuclear track detectors are employed to investigate the fluence anisotropy of charged particles (protons, deuterons and tritons) emitted from the focus region of a low energy Mather-type plasma focus energized by a single 32 μF, 15 kV (3.6 kJ) capacitor. The charged particle flux is the highest in the axial direction, and decreases towards the radial direction. The radial charged particles flux is six times smaller than the flux in the axial direction.


1973 ◽  
Vol 40 (1) ◽  
pp. 43-47 ◽  
Author(s):  
J. W. Rauscher ◽  
R. E. Kelly ◽  
J. D. Cole

An analysis on the basis of the Navier-Stokes equations is made of the flow of a liquid in a thin film on a rotating disk. Fluid flows outward in the radial direction due to the centrifugal force. An asymptotic solution valid for small values of the Rossby number is presented. Higher-order terms correcting for the effects of convection, Coriolis acceleration, radial diffusion, surface curvature, and surface tension are found and discussed on a physical basis.


2012 ◽  
Vol 510 ◽  
pp. 545-548
Author(s):  
Liang Yu ◽  
Shu Sheng Yuan ◽  
Zhi Bing Pang ◽  
Yun Liang Wang

RNG (Renormalization Group) k-ε turbulent model was applied to the numerical simulation of turbulent mixing processes in the RQL gas turbine combustor, and SIMPLE algorithm was used to solve the finite difference equations. The calculated conclusions were used to analyze temperature distribution of the mixed flow field and near-wall region of the flow field, and then discuss the NOx emissions. The results show that the effect of the injector zone geometry and the jet to crossflow momentum flux ratios on the NOx emissions is obvious. The reasonable control of jet is beneficial to reduce the local high temperature area and is able to improve the distribution of the exit temperature. And then achieve the goal of reducing the environmental pollution.


1988 ◽  
Vol 92 (920) ◽  
pp. 390-396 ◽  
Author(s):  
A. Klein

SummaryAn experimental correlation is presented between the losses and the inlet flow conditions in short dump diffusers for turbojet combustors. Cascades of compressor blades upstream of the diffuser were used to make the flow field at inlet similar to that in a real jet engine. The flow field was altered in two ways — by varying the distance between the cascades and the diffuser inlet plane and by changing the blade aspect ratio. The measurements show clearly that distortions in the radial direction affect the losses to a much larger extent than non-uniformities in the circumferential direction. In consequence, the performance can be correlated to a satisfactory degree of accuracy simply by using the radial blockage factor at inlet.


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