The Numerical Simulation of Internal Flow Field in Rotor Oil Pump

2012 ◽  
Vol 516-517 ◽  
pp. 1032-1035
Author(s):  
Chen Hai Guo ◽  
Jie Wen ◽  
Fei Dong
Keyword(s):  
Numerical Simulation ◽  
Velocity Vector ◽  
Flow Characteristic ◽  
Characteristic Curve ◽  
Maximum Velocity ◽  
Internal Flow ◽  
Experimental Result ◽  
Maximum Pressure ◽  
Oil Pump ◽  
Internal Velocity

Numerical simulation of rotor oil pump is completed by using SC/Tetra under variable conditions, which obtains the distribution of pressure and velocity. The pressure in the outlet oil chamber rises with rotation of rotor which makes the space smaller and smaller. In the result of postprocessor the maximum pressure is 4.3Mpa. This paper also studies on the internal velocity field distribution of pump body and pump cover. By the chart of velocity vector, fluid exists obvious reflow phenomenon. This is because of effection of the rotor rotation. The maximum velocity mainly exists in pump cover. Futhermore, flow characteristic curve is compared with the experimental result. The result basically shows the correctness of numerical simulation.

Impact Of Diffuser Width On The Performance Of AP1000 Reactor Coolant Pump

2012 ◽  
Vol 516-517 ◽  
pp. 921-925 ◽  
Author(s):  
Dan Qing Yuan ◽  
Hua Yan ◽  
Pei Pei Wang
Keyword(s):  
Numerical Simulation ◽  
Velocity Vector ◽  
Internal Flow ◽  
Meridian Plane ◽  
Coolant Pump ◽  
Ansys Cfx ◽  
Performance Curves ◽  
Ap1000 Reactor ◽  
Coefficient Method ◽  
Nuclear Coolant

For the problem of incapable to determine the width of spherical diffuser, four groups of spherial diffusers with different width were designed by using the speed coefficient method. Numerical investigation of internal flow in the nuclear coolant pumps with these diffusers was made based on ANSYS-CFX software. Aimed at the efficiency, ditribution of pressure and velocity vector on the meridian plane of each volute scheme was analysised emphatically. By comparing the performance curves of the coolant pumps predicted by the numerical simulation, we can draw that the head and efficiency of pump decreased as the increasing of diffuser width and performanced worst at the width of d=1.7R, then the performance no longer changes when diffuser width continue to reduce.

Optimization of Nonlinear Pressure-flow Characteristics of a Spring- Loaded Pressure Relief Valve Based on CFD Simulation

2021 ◽  
Author(s):  
Chengshuo Wu ◽  
Shiyang Li ◽  
Qianqian Li ◽  
Peng Wu ◽  
Bin Huang ◽  
...  
Keyword(s):  
Flow Characteristic ◽  
Characteristic Curve ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Relief Valve ◽  
Pressure Flow ◽  
Hydraulic Force ◽  
Middle Chamber ◽  
Valve Opening ◽  
Cfd Method

Abstract In this study, the nonlinear pressure-flow characteristics of a spring-loaded pressure relief valve (PRV) which is used in the automotive fuel supply system for pressure control is analyzed, and its characteristics are improved by means of geometrical modifications of the valve structure. Given the complexity of the coupling mechanism between the valve internal flow characteristics and spring system, a quasi-steady computational fluid dynamics (CFD) method is introduced to predict the nonlinear pressure-flow characteristic curve of the valve and the accuracy is validated by experimental data. The total hydraulic force on the valve spool and diaphragm are divided into three parts according to the position of action and the correlation between the internal flow characteristics, hydraulic force, and pressure-flow characteristics of the valve are explained by CFD analysis and visualization. The result shows that the quasi-steady CFD method can accurately predict the trends of the valve nonlinear pressure-flow characteristic curve which is mainly determined by the hydraulic force produced in the middle chamber of the valve, when the valve opening reaches a certain value, a main vortex would be formulated in the middle chamber and lead to the sudden increase of hydraulic force which causes the fluctuation of the pressure-flow characteristic curve of the valve. It was also found that by increasing the round corner size, the valve opening value of flow pattern change will be promoted and the valve pressure-flow characteristic can be optimized.

Investigation of the natural ventilation of wind catchers with different geometries in arid region houses

2020 ◽  
Vol 14 (3) ◽  
pp. 7109-7124
Author(s):  
Nasreddine Sakhri ◽  
Younes Menni ◽  
Houari Ameur ◽  
Ali J. Chamkha ◽  
Noureddine Kaid ◽  
...  
Keyword(s):  
Arid Region ◽  
Natural Ventilation ◽  
Reduction Rate ◽  
Internal Flow ◽  
Climatic Conditions ◽  
Maximum Pressure ◽  
Ventilation Technique ◽  
Window Position ◽  
The One ◽  
Flow Velocities

The wind catcher or wind tower is a natural ventilation technique that has been employed in the Middle East region and still until nowadays. The present paper aims to study the effect of the one-sided position of a wind catcher device against the ventilated space or building geometry and its natural ventilation performance. Four models based on the traditional design of a one-sided wind catcher are studied and compared. The study is achieved under the climatic conditions of the South-west of Algeria (arid region). The obtained results showed that the front and Takhtabush’s models were able to create the maximum pressure difference (ΔP) between the windward and leeward of the tower-house system. Internal airflow velocities increased with the increase of wind speed in all studied models. For example, at Vwind = 2 m/s, the internal flow velocities were 1.7, 1.8, 1.3, and 2.5 m/s for model 1, 2, 3, and 4, respectively. However, at Vwind = 6 m/s, the internal flow velocities were 5.6, 5.5, 2.5, and 7 m/s for model 1, 2, 3, and 4, respectively. The higher internal airflow velocities are given by Takhtabush, traditional, front and middle tower models, respectively, with a reduction rate between the tower outlet and occupied space by 72, 42, 36, and 33% for the middle tower, Takhtabush, traditional tower, and the front model tower, respectively. This reduction is due to the due to internal flow resistance. The third part of the study investigates the effect of window (exist opening) position on the opposite wall. The upper, middle and lower window positions are studied and compared. The air stagnation or recirculation zone inside the ventilated space reduced from 55% with the lower window to 46% for the middle window and reached 35% for the upper window position. The Front and Takhtabush models for the one-sided wind catcher with an upper window position are highly recommended for the wind-driven natural ventilation in residential houses that are located in arid regions.

scholarly journals Optimal Design of Slit Impeller for Low Specific Speed Centrifugal Pump Based on Orthogonal Test

2021 ◽  
Vol 9 (2) ◽  
pp. 121
Author(s):  
Yang Yang ◽  
Ling Zhou ◽  
Hongtao Zhou ◽  
Wanning Lv ◽  
Jian Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Pump ◽  
Large Scale ◽  
Internal Flow ◽  
Orthogonal Test ◽  
Centrifugal Pumps ◽  
Initial Model ◽  
Low Specific Speed ◽  
Specific Speed ◽  
Four Levels

Marine centrifugal pumps are mostly used on board ship, for transferring liquid from one point to another. Based on the combination of orthogonal testing and numerical simulation, this paper optimizes the structure of a drainage trough for a typical low-specific speed centrifugal pump, determines the priority of the various geometric factors of the drainage trough on the pump performance, and obtains the optimal impeller drainage trough scheme. The influence of drainage tank structure on the internal flow of a low-specific speed centrifugal pump is also analyzed. First, based on the experimental validation of the initial model, it is determined that the numerical simulation method used in this paper is highly accurate in predicting the performance of low-specific speed centrifugal pumps. Secondly, based on the three factors and four levels of the impeller drainage trough in the orthogonal test, the orthogonal test plan is determined and the orthogonal test results are analyzed. This work found that slit diameter and slit width have a large impact on the performance of low-specific speed centrifugal pumps, while long and short vane lap lengths have less impact. Finally, we compared the internal flow distribution between the initial model and the optimized model, and found that the slit structure could effectively reduce the pressure difference between the suction side and the pressure side of the blade. By weakening the large-scale vortex in the flow path and reducing the hydraulic losses, the drainage trough impellers obtained based on orthogonal tests can significantly improve the hydraulic efficiency of low-specific speed centrifugal pumps.

scholarly journals Numerical Study of Pressure Attenuation Effect on Tunnel Structures Subjected to Blast Loads

2021 ◽  
Vol 11 (12) ◽  
pp. 5646
Author(s):  
Cheng-Wei Hung ◽  
Ying-Kuan Tsai ◽  
Tai-An Chen ◽  
Hsin-Hung Lai ◽  
Pin-Wen Wu
Keyword(s):  
Numerical Simulation ◽  
Orifice Plate ◽  
Experimental Result ◽  
Scale Model ◽  
Pressure Reduction ◽  
Expansion Chamber ◽  
Pressure Relief ◽  
Attenuation Effect ◽  
The One ◽  
Better Than

This study used experimental and numerical simulation methods to discuss the attenuation mechanism of a blast inside a tunnel for different forms of a tunnel pressure reduction module under the condition of a tunnel near-field explosion. In terms of the experiment, a small-scale model was used for the explosion experiments of a tunnel pressure reduction module (expansion chamber, one-pressure relief orifice plate, double-pressure relief orifice plate). In the numerical simulation, the pressure transfer effect was evaluated using the ALE fluid–solid coupling and mapping technique. The findings showed that the pressure attenuation model changed the tunnel section to diffuse, reduce, or detour the pressure transfer, indicating the blast attenuation effect. In terms of the effect of blast attenuation, the double-pressure relief orifice plate was better than the one-pressure relief orifice plate, and the single-pressure relief orifice plate was better than the expansion chamber. The expansion chamber attenuated the blast by 30%, the one-pressure relief orifice plate attenuated the blast by 51%, and the double-pressure relief orifice plate attenuated the blast by 82%. The blast attenuation trend of the numerical simulation result generally matched that of the experimental result. The results of this study can provide a reference for future protective designs and reinforce the U.S. Force regulations.

Numerical Simulation of Interior Flow in Evaporation Droplet

2014 ◽  
Author(s):  
Qingming Dong ◽  
Zhentao Wang ◽  
Yonghui Zhang ◽  
Junfeng Wang
Keyword(s):  
Numerical Simulation ◽  
High Temperature ◽  
Internal Flow ◽  
Surface Force ◽  
Droplet Surface ◽  
Force Model ◽  
Marangoni Flow ◽  
High Temperature Area ◽  
Interior Flow ◽  
Temperature Area

In this present study, the VOF (Volume of Fluid) approach is adopted to capture the interface, and CSF (Continuum Surface Force) model to calculate the surface tension, and the governing equations are founded in numerical simulation of evaporating droplets. In this work, a water droplet is assumed to be suspending in high temperature air, and the gravity of a droplet is ignored. During evaporating process of the droplet, the internal circulation flow will be induced due to the gradient of temperature at the droplet surface. The interface flows from high temperature area to low temperature area, which pulls the liquid to produce convective flow inside the droplet called as Marangoni flow. Marangoni flow makes the temperature distribution tend to uniformity, which enhances heat transfer but weakens Marangoni flow in turn. So, during droplet evaporation, the internal flow is not steady.

Turbulence Model Influence on Numerical Investigation of Transonic Axial Compressor Rotor

2011 ◽  
Vol 308-310 ◽  
pp. 1519-1522
Author(s):  
Fang Xie ◽  
Chang Jiang Liu ◽  
You Jun Wang
Keyword(s):  
Experimental Data ◽  
Numerical Investigation ◽  
Turbulence Model ◽  
Characteristic Curve ◽  
Axial Compressor ◽  
Internal Flow ◽  
Turbulent Model ◽  
Compressor Rotor ◽  
Transonic Axial Compressor ◽  
Point Forecast

Numerical method using HI and HOH meshing combined B - L turbulent model and S - A turbulent model separately based on the Rotor 37 compressor Rotor was applied to the steady flow. results on pressure characteristic curve, stall point forecast etc were compared with related experimental data. This paper discussed calculation precision influenced by the turbulence model and numerical computation grid. This numerical investigation was basis for subsequent compressor internal flow field study.

Numerical Simulation Study of Metal Transfer in MIG Welding with Magnetic Control

2014 ◽  
Vol 532 ◽  
pp. 545-548 ◽  
Author(s):  
Chao Yang ◽  
Shu Yuan Jiang ◽  
Hai Bo Bi
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Mathematical Model ◽  
Simulation Study ◽  
Electromagnetic Theory ◽  
Metal Transfer ◽  
Experimental Result ◽  
Magnetic Control ◽  
Mig Welding ◽  
Model Based

This paper simulate the mode of metal transfer in MIG magnetic control welding by using CFD software FLUENT, establishing mathematical model based on fluid dynamics and electromagnetic theory, and simulate the form, grow and drop process of metal transfer with and without magnetic. Meanwhile, do experiments to confirm the simulate result, and it is well consistent with the experimental result.

scholarly journals The influence of axial-flow fan trailing edge structure on internal flow

2018 ◽  
Vol 10 (11) ◽  
pp. 168781401881174
Author(s):  
Weijie Zhang ◽  
Jianping Yuan ◽  
Banglun Zhou ◽  
Hao Li ◽  
Ye Yuan
Keyword(s):  
Numerical Simulation ◽  
Low Frequency ◽  
Axial Flow ◽  
Internal Flow ◽  
Axial Flow Fan ◽  
Trailing Edge ◽  
Edge Structure ◽  
Blade Loading ◽  
Wideband Noise ◽  
Fluctuation Amplitude

Axial-flow fan with advantages such as large air volume, high head pressure, and low noise is commonly used in the work of air-conditioner outdoor unit. In order to investigate the internal flow mechanism of the axial-flow fan with different trailing edge structures of impellers, four kinds of impellers were designed, and numerical simulation and experiment were deployed in this article. The pressure distribution on the blades surface and distribution of vorticity in impellers were obtained using numerical simulation. Distribution of blade loading and velocity at the circumference are discussed. The relationship between the wideband noise and the trailing edge was established based on the experiment results. The results show that after the optimization of the trailing edge structure, the distribution of vorticity near the trailing edge of the blade is more uniform, especially at the trailing edge of 80% of the chord length of the suction surface. From the blade height position of 70% to the impeller tip, the pressure on the surface rapidly increases due to the tip vortex and the vortex shedding on the blade edge occurred in the top region of impeller. The pressure fluctuation amplitude at the trailing edge structure of the tail-edge optimization structure is smaller. In the distribution of blade loading, the three tail-edge optimization structures have smaller pressure fluctuations and pressure differences at the trailing edge structure. It is extremely important to control the fluctuation amplitude at the trailing edge. The amplitude of low-frequency sound pressure level of optimizing the trailing edge structure decreases obviously in the range of 50–125 Hz, and the optimization structure of trailing edge has an obvious effect on low-frequency wideband noise.

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