Numerical Simulation of the Flow in a Large-Scale Thrust Bearing

2010 ◽  
Author(s):  
Hong-Jie Wang ◽  
Ru-Zhi Gong ◽  
De-Ping Lu ◽  
Zhong-De Wu ◽  
Feng-Chen Li
Keyword(s):  
Flow Field ◽  
High Speed ◽  
Large Scale ◽  
Thrust Bearing ◽  
Cfd Simulation ◽  
Internal Flow ◽  
Heat Radiation ◽  
Heavy Load ◽  
Cfd Method ◽  
Water Turbines

Thrust bearing is a key component of large-scale water turbine. It closely relates to the efficiency of large-scale water turbines, and even determines whether the large-scale turbine can operate normally. With the development of the capacitance of water turbines, thrust bearing will develop to the direction of high speed and heavy load. The structure, strength, lubrication and the characteristic of heat radiation of large-scale thrust bearing were often researched in the past. To study the flow condition of the large-scale thrust bearing and analyze the load characteristics, CFD simulation was carried out on the model of thrust bearing. In this study, CFD method was used to simulate the internal flow field of the large-scale thrust bearing. The model researched was a thrust bearing for 1000MW water turbines. The diameter of the thrust bearing was over 5.8 meters, and the maximum thrust load of the bearing can reach to 60MN. The thin gap between the runner and the pad was usually neglected in the published CFD calculations of thrust bearing. But the thin gap was taken into account in this investigation. 1/12 of the model was used as the computational field and periodic boundary was used in the calculation. The standard κ-ε turbulence model was used to simulate the thrust bearing model, and the flow field in the thrust bearing was obtained. The thin gap between the runner and the pad is a wedge. The pressure and velocity distribution in the thrust bearing and thin gap was calculated respectively with conditions of different thin gaps and different rotational speeds of runner. After that, the relationship between carrying capacity and the size of clearance or the speed of the runner through analyzing the data has been obtained from the results of the calculation.

Precision Compound Sand Control Screen Internal Flow Field of the CFD Simulation

2014 ◽  
Vol 644-650 ◽  
pp. 4682-4685
Author(s):  
Zhi Jian Wang ◽  
Tian Zhu Zhang ◽  
Jin Shang ◽  
Metsakeu Kong Evariste
Keyword(s):  
Flow Field ◽  
Cfd Simulation ◽  
Internal Flow ◽  
Screen Effect ◽  
Theoretical Support ◽  
Sand Control ◽  
Porous Media Model ◽  
Speed Change ◽  
Cfd Method ◽  
Production Losses

In this paper, calculating fluid dynamics (CFD) method is utilized for analyzing the precision compound sand control screen internal flow field so as to establish appropriate models. During this numerical calculation, by using the - turbulence model is used to simulate the resistance characteristics under different working conditions when crude oil flows through precision compound sand control screen, analyze its speed change rule, flow path and pressure distribution, etc. The use of porous media model to simulate the resistance of the oil screen effect, the oil screen is replaced by the porous jump surface to simulate the strainer of pressure drop. To screen sand control performance and reduce the flow resistance to provide theoretical support, make the reservoir production losses to a minimum.

The Criterion of Red Blood Cell’s Fragmentation and the Turbulent Flow Field Simulation Analysis in the High-Speed Spiral Blood Pump

2011 ◽  
Vol 422 ◽  
pp. 767-770
Author(s):  
Zhong Yun ◽  
Xiao Yan Tang ◽  
Chuang Xiang ◽  
Fen Shi
Keyword(s):  
Flow Field ◽  
Turbulent Flow ◽  
High Speed ◽  
Cfd Simulation ◽  
Simulation Analysis ◽  
Internal Flow ◽  
Blood Pump ◽  
Important Index ◽  
Simulation Results ◽  
Turbulent Flow Field

For a blood pump, the injury to blood is a very important index of its performance. The strongly swirling turbulent flow in the internal flow field of a high-speed spiral blood pump(HSBP), is one of important factors leading to the fragmentation of the red blood cell(RBC) and the hemolysis. The study on the turbulent injure principle of blood in the HSBP is carried out by using the theory of the turbulent flow field and the hemorheology. The determinant gist on RBC turbulent fragmentation is obtained. The turbulent flow in the designed HSBP have been simulated and analyzed by using the multiphase suspend body CFD simulation technology. The simulation results indicate that the turbulence in the designed HSBP can meet the requirements of blood physiology.

Research on CFD Simulation of the Cement Slurry Mixer

2012 ◽  
Vol 621 ◽  
pp. 196-199
Author(s):  
Shui Ping LI ◽  
Ya Li Yuan ◽  
Lu Gang Shi
Keyword(s):  
Flow Field ◽  
High Performance ◽  
Cfd Simulation ◽  
Structural Parameters ◽  
Internal Flow ◽  
Simulation Method ◽  
Cement Slurry ◽  
Fluid Machinery ◽  
Computational Fluid Dynamics Cfd ◽  
Machinery Design

Numerical simulation method of the internal flow field of fluid machinery has become an important technology in the study of fluid machinery design. In order to obtain a high-performance cement slurry mixer, computational fluid dynamics (CFD) techniques are used to simulate the flow field in the mixer, and the simulation results are studied. According to the analysis results, the structural parameters of the mixer are modified. The results show the mixer under the revised parameters meet the design requirements well. So CFD analysis method can shorten design period and provide valuable theoretical guidance for the design of fluid machinery.

scholarly journals Analysis and control of flow at suction connection in high-speed centrifugal pump

2017 ◽  
Vol 9 (1) ◽  
pp. 168781401668529 ◽  
Author(s):  
Wen-wu Song ◽  
Li-chao Wei ◽  
Jie Fu ◽  
Jian-wei Shi ◽  
Xiu-xin Yang ◽  
...  
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
High Speed ◽  
Internal Flow ◽  
Orifice Plate ◽  
Centrifugal Pumps ◽  
Pressure Area ◽  
Negative Effect ◽  
And Control ◽  
Experimental Data Analysis

The backflow vortexes at the suction connection in high-speed centrifugal pumps have negative effect on the flow field. Setting an orifice plate in front of the inducer is able to decrease the negative effect caused by backflow vortexes. The traditional plate is able to partially control the backflow vortexes, but a small part of the vortex is still in the inlet and the inducer. Four new types of orifice plates were created, and the control effects on backflow vortexes were analyzed. The ANSYS-CFX software was used to numerically simulate a high-speed centrifugal pump. The variations of streamline and velocity vectors at the suction connection were analyzed. Meanwhile, the effects of these plates on the impeller pressure and the internal flow field of the inducer were analyzed. Numerically, simulation and experimental data analysis methods were used to compare the head and efficiency of the high-speed pumps. The results show that the C-type orifice plate can improve the backflow vortex, reduce the low-pressure area, and improve the hydraulic performance of the high-speed pump.

A Transonic Compressor Stage: Part 2 — CFD Simulation

2004 ◽  
Author(s):  
G. V. Hobson ◽  
A. J. Gannon ◽  
R. P. Shreeve
Keyword(s):  
Cfd Simulation ◽  
Pressure Ratio ◽  
Internal Flow ◽  
Design Tool ◽  
Experimental Results ◽  
Navier Stokes ◽  
Experimental Program ◽  
Compressor Stage ◽  
Transonic Compressor ◽  
Cfd Method

The simulation of a transonic compressor stage is presented. This stage was designed using an Euler CFD code with the intent of minimizing the use of empirical design techniques. The stage has subsequently been built and tested. More recently an existing multi-block Navier-Stokes code with a steady averaging-plane to pass information between the blade rows was used to simulate the flow through the machine. Performance maps of stage pressure ratio and efficiency at 70, 80, 90 and 100% speeds from both the Euler and Navier-Stokes CFD codes are compared with the experimental results. Details of the internal flow from the Navier-Stokes code are presented. Comparison of the design Euler CFD and experimental results showed reasonable agreement and validated its use as a design tool. Agreement between experimental and the current Navier-Stokes CFD results was good, allowing the code to be used in the viewing of the internal flow field. Improvements to the initial design CFD method are discussed in light of the experimental program and more recent simulations.

scholarly journals Numerical Analysis on the Hydrodynamic Performance of an Artificially Ventilated Surface-Piercing Propeller

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1499 ◽  
Author(s):  
Dongmei Yang ◽  
Zhen Ren ◽  
Zhiqun Guo ◽  
Zeyang Gao
Keyword(s):  
High Speed ◽  
Artificial Ventilation ◽  
Water Immersion ◽  
Numerical Results ◽  
Hydrodynamic Performance ◽  
Heavy Load ◽  
Computational Fluid Dynamics Cfd ◽  
Large Water ◽  
Cfd Method ◽  
Surface Piercing Propeller

When operated under large water immersion, surface piercing propellers are prone to be in heavy load conditions. To improve the hydrodynamic performance of the surface piercing propellers, engineers usually artificially ventilate the blades by equipping a vent pipe in front of the propeller disc. In this paper, the influence of artificial ventilation on the hydrodynamic performance of surface piercing propellers under full immersion conditions was investigated using the Computational Fluid Dynamics (CFD) method. The numerical results suggest that the effect of artificial ventilation on the pressure distribution on the blades decreases along the radial direction. And at low advancing speed, the thrust, torque as well as the efficiency of the propeller are smaller than those without ventilation. However, with the increase of the advancing speed, the efficiency of the propeller rapidly increases and can be greater than the without-ventilation case. The numerical results demonstrates the effectiveness of the artificial ventilation approach for improving the hydrodynamic performance of the surface piercing propellers for high speed planning crafts.

Research Analysis and Experiment Study on Flow Field of Hydrodynamic Coupling

2011 ◽  
Vol 418-420 ◽  
pp. 2006-2011
Author(s):  
Rui Zhang ◽  
Cheng Jian Sun ◽  
Yue Wang
Keyword(s):  
Flow Field ◽  
Cfd Simulation ◽  
Two Phase Flow ◽  
Three Dimensional ◽  
Internal Flow ◽  
Phase Flow ◽  
Complex Flow ◽  
Two Phase ◽  
Operation Conditions ◽  
Hydrodynamic Coupling

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.

Study on the Turbulent Injury Principle of Blood in the High-Speed Spiral Blood Pump

2011 ◽  
Vol 393-395 ◽  
pp. 992-995
Author(s):  
Zhong Yun ◽  
Chuang Xiang ◽  
Xiao Yan Tang ◽  
Fen Shi
Keyword(s):  
Shear Stress ◽  
Flow Field ◽  
Blood Cell ◽  
Turbulent Flow ◽  
Red Blood Cell ◽  
Blood Cells ◽  
High Speed ◽  
Internal Flow ◽  
Blood Pump ◽  
Turbulent Flow Field

The strongly swirling turbulent flow in the internal flow field of a high-speed spiral blood pump(HSBP), is one of important factors leading to the fragmentation of the red blood cell(RBC) and the hemolysis. The study on the turbulent injure principle of blood in the HSBP is carried out by using the theory of waterpower rotated flow field and the hemorheology. The numerical equation of the strongly swirling turbulent flow field is proposed. The largest stable diameter of red blood cells in the turbulent flow field is analyzed. The determinant gist on the red blood cell turbulent fragmentation is obtained. The results indicate that in the HSMP, when turbulent flow is more powerful, shear stress is weaker, the vortex mass with energy in flow field may cause serious turbulent fragmentation because of the diameter which is smaller than the RBC’s. The RBC’s turbulent breakage will occur when the Weber value is larger than 12.

Detailed Flow Investigations Within a High-Speed Centrifugal Compressor Impeller

1976 ◽  
Vol 98 (3) ◽  
pp. 390-399 ◽  
Author(s):  
D. Eckardt
Keyword(s):  
Flow Field ◽  
Flow Pattern ◽  
High Speed ◽  
Internal Flow ◽  
Suction Side ◽  
Turbulence Structure ◽  
Wake Interaction ◽  
Compressor Impeller ◽  
Channel Curvature ◽  
Relative Flow

Detailed accurate measurements of velocities, directions, and fluctuation intensities were performed with a newly developed laser velocimeter in the internal flow field of a radial discharge impeller, running at tip speeds up to 400 m/s. Relative flow distributions are presented in five measurement areas from inducer inlet to impeller discharge. The impeller flow pattern, which coincides largely with potential-theory calculations in the axial inducer, becomes more and more reversed when the flow separates from the blade suction side, developing a rapidly increasing wake in the radial impeller. The observed secondary flow pattern and effects of channel curvature and system rotation on turbulence structure are discussed with respect to separation onset and jet/wake interaction.

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