scholarly journals Analysis and Research on Flow Characteristics of Hot Water Pipeline System

2021 ◽  
Vol 252 ◽  
pp. 03041
Author(s):  
Hou Yingzhe ◽  
Wu Hao ◽  
Yan Xiaozhe ◽  
Zhu Haoqiang ◽  
Gao Haitao ◽  
...  
Keyword(s):  
Flow Field ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Simulation Method ◽  
Hot Water ◽  
Pipeline System ◽  
Pipe System ◽  
Uniformity Coefficient ◽  
Pipe Model ◽  
Pipeline Vibration

Based on the CFD numerical simulation method, a pipe model was established to study the internal flow characteristics of two different specifications of hot water pipe system, and the related information of the flow field was obtained, such as the internal pressure, flow velocity and flow rate. The results showed that the smoother the pipeline transition was, the smaller the velocity uniformity coefficient would be, and the higher flow field uniformity means the smaller pressure and velocity fluctuations. Therefore, the pipeline vibration will be smaller, and the flow characteristics are greatly improved.

scholarly journals Comparative Study on Flow Characteristics of Pipeline System Based on CFD

2021 ◽  
Vol 252 ◽  
pp. 02053
Author(s):  
Hou Yingzhe ◽  
Wu Hao ◽  
Yan Xiaozhe ◽  
Zhu Haoqiang ◽  
Gao Haitao ◽  
...  
Keyword(s):  
Flow Field ◽  
Flow Rate ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Simulation Method ◽  
Hot Water ◽  
Pipeline System ◽  
Uniformity Coefficient ◽  
Study Results ◽  
Pipeline Vibration

Based on the CFD numerical simulation method, this paper established a pipeline model to study the internal flow characteristics of three different combinations of hot water pipeline systems and thus obtained the flow field information such as pressure, flow rate, and flow rate inside the pipeline. The study results showed that the smoother the pipeline transition, the smaller the velocity uniformity coefficient; the higher the uniformity of the flow field, the smaller the pressure and velocity fluctuations, the smaller the resulting pipeline vibration. Besides, the flow characteristics have been greatly improved.

Study on the Flow Characteristics of the Monolithic Muffler in Train Air Conditioning Duct

2012 ◽  
Vol 462 ◽  
pp. 300-306
Author(s):  
Xu Quan Li ◽  
Dong Dong Dong ◽  
Min Jie Gu ◽  
Gang Wang ◽  
Song Tao Hu
Keyword(s):  
Flow Field ◽  
Pressure Loss ◽  
Air Conditioning ◽  
Cfd Simulation ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Simulation Method ◽  
Calculation Model ◽  
Simulation Calculation ◽  
Performance Research

After installing the monolithic muffler in the train air duct, noise is reduced, but meanwhile also increased the air duct resistance. In this paper, a monolithic muffler simulation calculation model is introduced in this paper. The pressure loss and internal flow field of the muffler are obtained by. CFD simulation. Experimental results validate the simulation method. It provides a basis for the silencer performance research of muffler.

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.

scholarly journals Study on the 3D Hydrodynamic Characteristics and Velocity Uniformity of a Gravity Flow Circular Flume

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 927
Author(s):  
Yi Zhang ◽  
Longxi Han ◽  
Lina Chen ◽  
Chenfang Wang ◽  
Bo Chen ◽  
...  
Keyword(s):  
Flow Field ◽  
Environmental Science ◽  
Structural Characteristics ◽  
Longitudinal Velocity ◽  
Flow Characteristics ◽  
Science Research ◽  
Hydrodynamic Characteristics ◽  
Straight Channel ◽  
Uniformity Coefficient ◽  
Annular Flume

Flumes have been widely used in water conservancy science and environmental science research. It is of great significance to obtain the hydrodynamic characteristics and flow field uniformity in the flume. In this study, a new type of annular flume was taken as an example. The 3D flow field was simulated by using a commercial computational fluid dynamics (CFD) code, and was also measured by acoustic doppler velocimeter (ADV) to verify the simulation results. The average relative error range was between 8.37% and 9.95%, the simulated results basically reflected the actual situation of the flow field. On this basis, the structural characteristics of flow field were analyzed. A new calculation method of flow velocity uniformity was presented according to the flow characteristics of natural open channels. The velocity uniformity in the straight channel was calculated and analyzed based on this method, and the influence of speed on the velocity uniformity was further discussed. The length of uniform section was negatively correlated with the rotational speed (average velocity), which was between 39 cm and 101 cm in the straight, and the uniformity coefficient was less than 10%. Finally, the water flow characteristics in the straight channel without wheel were compared with the natural open channel flow. The longitudinal velocity was well fitted with the Prandtl logarithmic distribution formula (R2 > 0.977), and the application feasibility of the flume was analyzed. This study can provide technical support for the development and application of annular flume.

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 Numerical Simulation and Experimental Study on Flow Field in a Swirl Nozzle

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yicheng Sun ◽  
Yufan Fu ◽  
Baohui Chen ◽  
Jiaxing Lu ◽  
Wanquan Deng
Keyword(s):  
Flow Field ◽  
Velocity Distribution ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Low Pressure ◽  
External Flow ◽  
Droplet Velocity ◽  
Inlet Pressure ◽  
Outlet Section ◽  
Local Pressure

In order to study the internal flow characteristics and external droplet velocity distribution characteristics of the swirl nozzle, the following methods were used: numerical simulations were used to study the internal flow characteristics of a swirl nozzle and phase Doppler particle velocimetry was used to determine the corresponding external droplet velocity distribution under medium and low pressure conditions. The distributions of pressure and water velocity inside the nozzle were obtained. Meanwhile, the velocities of droplets outside the nozzle in different sections were discussed. The results show that the flow rate in the swirl nozzle increases with the increase in inlet pressure, and the local pressure in the region decreases because of the excessive velocity at the internal outlet section of the swirl nozzle, resulting in cavitation. The experimental results show that under an external flow field, the minimum droplet velocity occurs in the axial direction; starting from the axis, the velocity first increases and then decreases along the radial direction. Swirling motion inside the nozzle and velocity variations in the external flow field occur under medium and low pressure conditions. The relationship between the inlet pressure and the distributions of water droplets’ velocities was established, which provides a reference for the research and development of the swirl nozzle.

Research on Flow Characteristics of Aerostatic Circular Thrust Bearing with a Cone Cavity

2011 ◽  
Vol 308-310 ◽  
pp. 189-192
Author(s):  
Long Xing Chen ◽  
Wen Qi Ma ◽  
He Chun Yu ◽  
Hai Yan Liu ◽  
Hong Wang Du
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Thrust Bearing ◽  
Single Point ◽  
Flow Characteristics ◽  
Simulation Method ◽  
Flow Passage ◽  
Testing Method ◽  
Measurement Results ◽  
Simulation And Experiment

The aerostatic circular thrust bearing was taken as a study subject. The numerical simulation method was used to calculate the flow passage. Meanwhile, the single-point testing method was used to test the pressure distribution. The simulation and experiment measurement results were compared and analyzed. The results show that: The single-point testing method is effective to capture the change of flow characteristics. The overall results of simulation and testing coincide with each other well. In the range of cone cavity, the flow pattern for the gas is turbulent flow, and the flow field should be divided into different zones for simulation.

scholarly journals 1D-3D coupling investigation of hydraulic transient for power-supply failure of centrifugal pump-pipe system

2019 ◽  
Vol 21 (5) ◽  
pp. 708-726 ◽  
Author(s):  
Xiaoqin Li ◽  
Xuelin Tang ◽  
Min Zhu ◽  
Xiaoyan Shi
Keyword(s):  
Turbulent Flows ◽  
Flow Rate ◽  
Power Supply ◽  
Nuclear Power ◽  
Transient Flow ◽  
Internal Flow ◽  
Transition Process ◽  
Pipeline System ◽  
Pipe System ◽  
Rotating Speed

Abstract In the pumping station, the main feedwater system and the reactor system of nuclear power plant, power-supply failure causes strong hydraulic transients. One-dimensional method of characteristics (1D-MOC) is used to calculate the transient process in the pipeline system while three-dimensional (3D) computational fluid dynamics is employed to analyze the turbulent flows inside the pump and to obtain the performance parameters of the pump, and the data exchanges on the boundary conditions of the shared interface between 1D and 3D domains are updated based on the MpCCI platform. Based on the equation of motion of the pump motion parts, the relationship between the external characteristics and the internal flow field in the pump is further investigated because the dynamic behavior of the pump and the detailed fluid field evolutions inside the pump are captured during the transition process, and the transient flow rate, rotating speed, and pressure inside the impeller are comprehensively investigated. Meanwhile, compared with the data gained by experiment and traditional 1D-MOC, the relative errors of rotating speed and the flow rate obtained by 1D-3D coupling method are smaller than those by 1D-MOC. Furthermore, the influences of the main coupling parameters and coupling modes on the calculation results are analyzed, and the cause of the deviation is further explained.

Aerodynamic Simulation of Road Vehicle in Steady Crosswind

2013 ◽  
Vol 376 ◽  
pp. 341-344
Author(s):  
Shan Ling Han ◽  
Ru Xing Yu ◽  
Yu Yue Wang ◽  
Gui Shen Wang
Keyword(s):  
Flow Field ◽  
Wind Direction ◽  
Motor Vehicle ◽  
Aerodynamic Force ◽  
Flow Characteristics ◽  
Simulation Method ◽  
Aerodynamic Characteristics ◽  
External Flow ◽  
Slant Angle ◽  
Ahmed Body

Because crosswind affects drivers to control their vehicles safely, the research on flow characteristics in automotive crosswind has a great significance to improve the crosswind stability of the vehicle. By the steady state numerical simulation method, the aerodynamic characteristics of external flow field of Ahmed body in crosswind was investigated. The Ahmed body with 25° slant angle is built in UG NX. The external flow field of the Ahmed body in the wind direction of 0°, 15º, 30° angle is simulated in XFlow software. According to the map of the pressure and velocity distribution, the flow field both before and after, as well as left and right has significant change as the wind direction angle increased, and the trail turbulence intensity also changes. The changes of aerodynamic force and moment affect the driving stability of a motor vehicle.

Numerical Simulation of Interior Flow Field of Reactor Coolant Pump under Station Blackout Accident

2012 ◽  
Vol 455-456 ◽  
pp. 1002-1008 ◽  
Author(s):  
Yi Ming Xu ◽  
Shi Ming Xu
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Internal Flow ◽  
Simulation Method ◽  
Governing Equations ◽  
Coolant Pump ◽  
Reactor Coolant ◽  
Internal Characteristic ◽  
Station Blackout ◽  
Interior Flow

Numerical simulation is used for researching the transient characteristic and internal characteristic of the reactor coolant pump under station blackout accident. The simulation method has been presented by analyzing difference scheme for governing equations. The analytical model of reactor coolant pump flow field has been established by analyzing adequately the influence of varying rotation speed to the pump external characteristic. Finally, the pump internal flow characteristic is exposed.

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