scholarly journals Numerical Investigation of the Flow Field and Mass Transfer Characteristics in a Jet Slurry Pump

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 2053
Author(s):  
Yi’nan Qian ◽  
Yuanshun Wang ◽  
Zhenlong Fang ◽  
Xiuhan Chen ◽  
Sape A. Miedema
Keyword(s):  
Flow Field ◽  
Numerical Study ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Internal Flow ◽  
Axial Line ◽  
Suction Pressure ◽  
Flow Ratio ◽  
Jet Pump ◽  
Mixing Chamber

A jet pump is used to transport a variety of working media and is especially suitable for dredged soil transporting. In this study, a three-dimensional numerical study of a jet pump that is used for slurry delivery was carried out. The characteristics of the internal flow field of the mixing chamber with different working parameters were comprehensively analyzed. The results indicate that the pressure of the axial line decreases with increasing flow ratio (ratio of suction flux and inlet flux) while the pressure of the injected slurry shows a downward trend. With the increase in the flow ratio, the pressure ratio (difference between inlet pressure and suction pressure divided by the difference between exit pressure and suction pressure) falls off while the efficiency presents a parabolic distribution. The pressure ratio can be promoted by properly increasing the length of the mixing chamber so that the available efficiency is broadened. When the mixing chamber length is L = 2.5Dn~4.0Dn (Dn is nozzle outlet diameter), the highly efficient area is wide; in particular, when L = 3.5Dn, the jet slurry pump with the highest efficiency of 27.6% has the best performance.

scholarly journals Numerical Study of the Internal Flow Field of a Centrifugal Impeller

1994 ◽  
Author(s):  
Mou-jin Zhang ◽  
Chuan-gang Gu ◽  
Yong-miao Miao
Keyword(s):  
Flow Field ◽  
Stokes Equations ◽  
Numerical Study ◽  
Three Dimensional ◽  
Simple Algorithm ◽  
Internal Flow ◽  
Staggered Grid ◽  
Navier Stokes ◽  
Centrifugal Impeller ◽  
High Reynolds

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.

Experimental and Numerical Investigation of a Centrifugal Compressor and Numerical Study of the Area Ratio and Tip Clearance Effects on the Performance Characteristic

2008 ◽  
Author(s):  
Mahdi Nili-Ahmadabadi ◽  
Ali Hajilouy-Benisi ◽  
Mohammad Durali ◽  
Sayyed Mostafa Motavalli
Keyword(s):  
Flow Field ◽  
Centrifugal Compressor ◽  
Numerical Study ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Area Ratio ◽  
Tip Clearance ◽  
Performance Characteristics ◽  
Navier Stokes ◽  
Sst Turbulence Model

In this research, the centrifugal compressor of a turbocharger is investigated experimentally and numerically. Performance characteristics of the compressor were obtained experimentally by measurements of rotor speed and flow parameters at the inlet and outlet of the compressor. Three dimensional flow field in the impeller and diffuser was analyzed numerically using a full Navier-Stokes program with SST turbulence model. The performance characteristics of the compressor were obtained numerically, which were then compared with the experimental results. The comparison shows good agreement. Furthermore, the effect of area ratio and tip clearance on the performance parameters and flow field was studied numerically. The impeller area ratio was changed by cutting the impeller exit axial width from an initial value of 4.1 mm to a final value of 5.1 mm, resulting in an area ratio from 0.792 to 0.965. For the rotor with exit axial width of 4.6 mm, performance was investigated for tip clearance of 0.0, 0.5 and 1.0 mm. Results of this simulation at design point showed that the compressor pressure ratio peaked at an area ratio of 0.792 while the efficiency peaked at a higher value of area ratio of 0.878. Also the increment of the tip clearance from 0 to 1 mm resulted in 20 percent efficiency decrease.

Numerical Analysis of Internal Flow Field in an Impeller with the Time Marching Method

2011 ◽  
Vol 94-96 ◽  
pp. 1476-1480
Author(s):  
Cai Hua Wang
Keyword(s):  
Flow Field ◽  
High Speed ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Internal Flow ◽  
Centrifugal Impeller ◽  
Three Dimensional Flow ◽  
Vector Distribution ◽  
Time Marching ◽  
Marching Method

Centrifugal compressors are power machineries used widely. Fully understanding of the complex three-dimensional flow field is very important to design higher pressure ratio, higher efficiency centrifugal compressor. In this paper, time marching method is adopted to solve the three-dimensional viscous N-S equations under the relative coordinate system. The internal flow field of the “full controllable vortex” high speed centrifugal impeller is analyzed and the medial velocity vector distribution and the development of the velocity of each section in the impeller are showed. From the figures, it can be seen that the “wake” phenomenon, such as Ecckart described, caused by the curvature, Coriolis force and the boundary layer is exist

Numerical study on the Effect of Interaction Vaned Diffuser with Impeller on the Performance of a Modified Centrifugal Compressor

2013 ◽  
Vol 30 (2) ◽  
pp. 113-121 ◽  
Author(s):  
L. H. Jawad ◽  
S. Abdullah ◽  
R. Zulkifli ◽  
W. M. F. W. Mahmood
Keyword(s):  
Centrifugal Compressor ◽  
Numerical Study ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Internal Flow ◽  
Compressor Stage ◽  
Vaned Diffuser ◽  
Centrifugal Compressor Stage ◽  
Compressor Impeller ◽  
Inlet Conditions

ABSTRACTThis paper is a numerical simulation that was made in the three-dimensional flow, carried out in a modified centrifugal compressor, having vaned diffuser stage, used as an auto-motive turbo charger. Moreover, the performance of the centrifugal compressor was dependent on the proper matching between compressor impeller and vaned diffuser, influencing significantly surge and the efficiency of centrifugal compressor stages. In addition, a modified compressor impeller, coupled with vane and vaneless diffuser, has been found to have similar internal flow patterns for both the vaneless and vaned diffuser design. The vaned diffuser effect has been paid particular attention in terms of better analysis where the diffuser was designed for high sub-sonic inlet conditions. Another aim of this research was to study and simulate the effect of vaned diffuser on the performance of a centrifugal compressor. The simulation was undertaken by using a commercial software, the so-called ANSYS CFX, to predict numerically the performance in terms of pressure ratio, poly tropic efficiency and mass flow rate for the centrifugal compressor stage. The results were generated from CFD and were analyzed for better understanding of the fluid flow through centrifugal compressor stage. Conclusively, it was observed that the effect of the vaned diffuser is to convert the kinetic energy into a high static pressure after analyzing the results of the simulation.

scholarly journals Influence of guide vanes on the flow fields and performance of axial pump under unsteady flow conditions: Numerical study

2020 ◽  
Vol 14 (2) ◽  
pp. 6570-6593 ◽  
Author(s):  
Ahmed Ramadhan Al-Obaidi
Keyword(s):  
Flow Field ◽  
Unsteady Flow ◽  
Numerical Study ◽  
Dynamic Pressure ◽  
Three Dimensional ◽  
Axial Flow ◽  
Internal Flow ◽  
Design Flow ◽  
Guide Vanes ◽  
Axial Pump

Influence of different guide vanes on structural of flow field and axial pump performance under unsteady flow is carried out using numerical method. A three-dimensional axial flow pump model is numerically simulated using computational fluid dynamics (CFD) method with four number of impeller blades and 3, 4, 5 and 6 guide vanes depend on the SIMPLE code, standard turbulence k-ε model as well as sliding mesh method (SMM). The static, dynamic, total pressures, shear stress, velocity magnitude and turbulent kinetic energy are the important features which affecting instability operation in the pump. By monitoring above parameters and setting different measurement pressure points, the average pressures in the pump are discussed and the effect of guide vanes on the average pressure is analyzed. The results demonstrate that the numerical calculations can provide good accurately prediction for the characteristics of internal flow in the pump. The numerical results are closed to experimental results the minimum errors of pressure differences can reach 2.5% and the maximum errors 6.5%. The guide vanes have more effect on the flow field and pressure variations especially at outlet region in the axial pump. As compared with the using various guide vanes, the pressure increases as number of vanes increase that can lead the performance of pump also increases. Pressure differences in the pump at variety mass flow for vane 6 is higher than other vanes 3, 4 and 5 by 14.13, 11.35 and 3.85% for flow of 5 L/min. Further, the dynamic pressure differences for design flow between different vanes 6, 5, 4 and 3 are about by 2.87, 7.26 and 8.51% respectively.

scholarly journals Numerical Investigation of Internal Flow Field for Modified Design of Eckardt Backswept Impeller

1998 ◽  
Author(s):  
JongSik Oh
Keyword(s):  
Flow Field ◽  
Static Pressure ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Internal Flow ◽  
Aerodynamic Characteristics ◽  
Uniform Flow ◽  
Spanwise Direction ◽  
Vaneless Diffuser ◽  
Blade Thickness

The three dimensional blade shape of Eckardt’s backswept impeller was modified, expecting better aerodynamic performance of the internal flow field. Blade angle distributions and parts of the meridional contours were changed, while impeller diameter, blade number, blade thickness and blade inlet and exit angles remained unchanged. The casing contour in the vaneless diffuser is additionally changed in a smooth manner to obtain 15% pinched flow channel at the exit. With the help of the three dimensional compressible Navier-Stokes analysis method, some improvements in the aerodynamic characteristics of the internal flow field were found; a more uniform flow field in the circumferential direction at impeller discharge was established, and a more favorable rise of static pressure near the casing in the impeller passage was made. A more effective increase of static pressure in the vaneless diffuser was also found. But a less uniform flow field in the spanwise direction at impeller exit resulted. The same levels of total-to-total pressure ratio and isentropic efficiency of the compressor were obtained, while an increase of choking flow rate was obtained due to increased throat area.

scholarly journals Numerical Study on the Working Performance of a Streamlined Annular Jet Pump

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4411
Author(s):  
Xiaodong Wang ◽  
Yunliang Chen ◽  
Mengqiu Li ◽  
Yong Xu ◽  
Bo Wang ◽  
...  
Keyword(s):  
Flow Field ◽  
High Efficiency ◽  
Numerical Study ◽  
Flow Ratio ◽  
Jet Pump ◽  
Local Pressure ◽  
Maximum Increase ◽  
Annular Jet ◽  
Working Performance ◽  
Annular Jet Pump

To improve the working performance of the early annular jet pump (EAJP), a streamlined annular jet pump (SAJP) was proposed. The flow field and working performance of the EAJP and SAJP with an area ratio (m) of 1.75 were numerically studied and compared, separately, by using the combination of the Realizable k-ε turbulence model and the Schnerr–Sauer cavitation model. The results show that the efficiency of the SAJP is higher than that of the EAJP, when the flow ratio (q) is higher than 0.30, with a maximum increase of 1.2%. Furthermore, the high-efficiency area of the SAJP (q = 0.40~0.69) is wider than that of the EAJP (q = 0.36~0.57). There is no flow separation and low local pressure in the SAJP, due to the conjunction part of the suction chamber, throat, diffuser and outlet pipe without the structural mutation. It was found that the incipient cavitation number (σi) of the SAJP and EAJP was 0.541 and 0.578, respectively; therefore, the cavitation performance of the SAJP is better. Meanwhile, the critical flow ratio (qc) of the SAJP is 0.69, which is larger than that of the EAJP (qc = 0.57), implying that the SAJP has a wider normal working range than the EAJP. Importantly, the inception and development of cavitation appeared in the diffuser of the SAJP, different from that in the throat of the EAJP. Hence, it concluded that the cavitation in the SAJP has less influence on the flow field and working performance.

Numerical Study on the Effects of Blade Lean on High-Pressure Centrifugal Impeller Performance

2011 ◽  
Author(s):  
JongSik Oh ◽  
Charles W. Buckley ◽  
Giri L. Agrawal
Keyword(s):  
High Pressure ◽  
Degrees Of Freedom ◽  
Numerical Solutions ◽  
Numerical Study ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Internal Flow ◽  
Secondary Flows ◽  
Centrifugal Impeller ◽  
High Pressure Ratio

Blade lean and sweep are additional degrees of freedom for the three dimensional blade design. When compared to blade sweep, the influence of blade lean on the performance is not extensively described in the public literature. The effects of blade lean on the aerodynamic performance of a high-pressure ratio centrifugal impeller were investigated using a CFD (Computational Fluid Dynamics) approach. For total of 15 variations of blade lean given at the impeller inlet and outlet, while blade angles at the impeller inlet and outlet were unchanged, numerical solutions of the impeller with a vaneless diffuser were obtained at the design speed from a maximum choke flow to a minimum flow available. Compressor performance maps were generated to compare overall characteristics, and details of internal flow structure at 5 different quasi-orthogonal planes were investigated to see the effects of blade lean on the development of secondary flows. It was found that a positive lean at the impeller exit shroud helps mitigate the wake region to contribute to more uniform flows, resulting in an increase of the impeller pressure and efficiency. A negative lean at the impeller exit causes a limited head rise due to a reduced blade loading on the shroud. A negative inlet lean at the shroud provided the worst performance.

Numerical Study on Mechanical Characteristics of Steam Turbine Valve Disc

2013 ◽  
Vol 572 ◽  
pp. 319-322
Author(s):  
Dong Yue Qu ◽  
Zhong Yuan Guo ◽  
Chong Liu
Keyword(s):  
Flow Field ◽  
Axial Force ◽  
Numerical Study ◽  
Pressure Ratio ◽  
Flow Characteristics ◽  
Control Valve ◽  
Internal Flow ◽  
Simulation Method ◽  
Complex Flow ◽  
Valve Stem

The instability flow in the control valve often lead to abnormal vibration, the valve wear and the valve stem destruction, also lead to pressure loss. The flow in the control valve show complex flow regime distribution and variation, it is a typical unsteady flow. Therefore, it is necessary to theoretical calculation and qualitative analyses the flow field of valve by the numerical simulation method. In this paper, we study on the axial force of valve stem that caused by the fluid pulsation pressure. Establishing the flow field model of the control valve, generating the computational grid through the pre-processor, using the CFD software to do discretized and solved, getting visualization graphics of the internal flow field. Study the changes of the flow characteristics according to different pressure ratio, getting the variation characteristic of axial force. Provide the basis for subsequent optimization and design of the low vibration control valve.

THE INTERNAL FLOW FIELD ASSOCIATED WITH YAWED THREE-DIMENSIONAL RECTANGULAR CAVITIES

2000 ◽  
Vol 7 (3) ◽  
pp. 14
Author(s):  
Eric Savory ◽  
Norman Toy ◽  
Shiki Okamoto ◽  
Yoko Yamanishi
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Internal Flow
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