Numerical Simulation on the Parallel Combined Nozzles of Mini/Micro Gas Flow Standard Device

2012 ◽  
Vol 472-475 ◽  
pp. 2000-2003
Author(s):  
Jin Long Meng ◽  
Zhao Qin Yin
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Flow Rate ◽  
Gas Flow ◽  
Flow Characteristics ◽  
Micro Gas Flow ◽  
Actual Flow Rate ◽  
Actual Flow ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

The flow characteristics in mini/micro sonic nozzles have been studied in this paper using the computational fluid dynamics (CFD) method. The result shows that the flow rate of the parallel combined nozzles is not equal to but smaller than that of the sum of the nozzles. The reason is the each effect of the air after nozzles, which changes the flow field parameters .The more number of the parallel combined nozzles, the bigger error exits between actual flow rate and that of the sum of the nozzles. The result is consistent to the experiment. The study also shows the smaller of the nozzle’s diameter, the bigger error exits.

Numerical Simulation of Quenchant Flow Characteristics in Large Quench Tank

2012 ◽  
Vol 271-272 ◽  
pp. 1372-1376
Author(s):  
Hui Sun
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Flow Field ◽  
Flow Rate ◽  
Inner Core ◽  
Flow Characteristics ◽  
Structure Design ◽  
Inner Surface ◽  
Computational Fluid Dynamics Cfd

The computational fluid dynamics (CFD) technique is employed to predict the flow of quenchant in a large quench tank. The characteristics of flow field in the existing quench tank are investigated, and the major deficiency occurred in the tank structure design is analyzed. Two different schemes for improving the tank structure design are brought forward, and further numerical simulations are carried out. Results show that the non-uniform flow field is generated throughout the quenching zone in the existing large quench tank. There is clear difference in flow rate in the regions near the inner surface of workpiece and the outer, which may cause the workpiece distortion and even cracking. Reduction in ring pipe intermediate diameter can not obviously enhance the uniformity of flow field in the quench tank. By adding an inner core in the center zone of the tank, the flow rate in the region near the inner surface of workpiece can be increased effectively, and the flow rate difference found in the quenching zone reduced significantly, which are beneficial to guarantee the quenching quality of workpiece.

Numerical Simulation of Campus Wind Environment

2010 ◽  
Vol 160-162 ◽  
pp. 280-286
Author(s):  
Ri Chao Liu ◽  
Zhong Hua Tang ◽  
Wei Yang Qi
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Wind Direction ◽  
Natural Ventilation ◽  
Pressure Field ◽  
Field Analysis ◽  
Wind Environment ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
Rng Turbulence Model

This paper adopted computational fluid dynamics (CFD) method, used k-ε RNG turbulence model-closed control differential equations for numerical simulation. Through numerical simulation and analysis of wind environment in a middle school campus, the round wind field under dominant wind direction was got in the summer and winter. According to the results of velocity field and pressure field, analysis the wind environment, compared the influence of wind direction and surrounding buildings space to the natural ventilation, provided guidance introduce for the layout of the school.

scholarly journals Numerical Simulation of the Hydrodynamics of Some Sectors of the Prute River

2019 ◽  
Vol 70 (3) ◽  
pp. 902-905
Author(s):  
Galina Marusic ◽  
Valeriu Panaitescu
Keyword(s):  
Water Pollution ◽  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Flow Characteristics ◽  
Aquatic Systems ◽  
Cfd Analysis ◽  
Computational Fluid Dynamics Cfd ◽  
Prut River

This paper addresses issues related to the determination of hydrodynamics of aquatic systems, with the application of computational fluid dynamics (CFD) analysis. The importance of knowing the hydrodynamics of aquatic systems for solving water pollution problems, as well as their prevention, is discussed. A case study regarding the determination of the water flow characteristics using CFD for some sectors of the Prut river is presented.

Numerical Simulation of Cross-Ventilation in Buildings Affected by Surrounding Buildings with Different Separation Distances

2013 ◽  
Vol 353-356 ◽  
pp. 2993-2996 ◽  
Author(s):  
Tao Tao Shui ◽  
Jing Liu ◽  
Fei Ma
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Street Canyon ◽  
Natural Ventilation ◽  
Flow Characteristics ◽  
Airflow Rate ◽  
Computational Fluid Dynamics Cfd ◽  
Simulation Results ◽  
Des Model

In order to investigate natural cross-ventilation in buildings, computational fluid dynamics (CFD) with the DES model is applied. The aim of this paper is to investigate the influence of surrounding buildings on natural ventilation in target building under different separation distances. The simulation results indicate that surrounding buildings has a significant impact on airflow structure and airflow rate of the target building. The flow characteristics in target building is determined by the flow regime in street canyon.

Numerical Simulation and Application of Gas Flow Distribution of ESP Transformed to Baghouse in Cement Kiln Head

2011 ◽  
Vol 130-134 ◽  
pp. 2715-2718
Author(s):  
Xiao Qing Dang ◽  
Hong Sheng Hu ◽  
Pang Min
Keyword(s):  
Numerical Simulation ◽  
Gas Flow ◽  
Dust Emission ◽  
Flow Distribution ◽  
Cement Kiln ◽  
Dust Collector ◽  
Air Volume ◽  
Configuration Parameter ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

By using Computational Fluid Dynamics (CFD) method,numerical simulation of gas flow distribution of ESP transform to baghouse in cement kiln head of 6000 t/d production. Through numerically simulation,air volume of every filter bag cell and head-on gas flow velocity distribution of filter bag were displayed. By adjusting the configuration parameter of the gas flow distribution device during the numerical simulation, it gives the result that the manner of installing gas flow distribution device, when the windage of the air volume of every filter bag cell is not more than 5% and the press drop of the dust collector with clean filter bag is 300 Pa. The calculated results showed good agreement with the measured results in the field. The simulation results were carried out by transformation. The dust emission concentration of precipitator is 26.6 mg/m3, and the dust running resistance is less than 1000Pa, can achieve the performance assessment requirements.

Mechanism and Characteristics of Horizontal-Wellbore Cleanout by Annular Helical Flow

SPE Journal ◽  
2013 ◽  
Vol 19 (01) ◽  
pp. 45-54 ◽  
Author(s):  
Song Xianzhi ◽  
Li Gensheng ◽  
Huang Zhongwei ◽  
Zhang Laibin ◽  
Tian Shouceng ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
High Pressure ◽  
Flow Rate ◽  
Tangential Velocity ◽  
Helical Flow ◽  
Hydraulic Parameters ◽  
Computational Fluid Dynamics Cfd ◽  
Horizontal Wellbore ◽  
Cfd Method ◽  
Significant Factors

Summary Horizontal-wellbore cleanout by rotating jets and annular helical flow has developed rapidly in past decades, in which the annular helical flow is one of the most significant factors to transport the solids in a horizontal wellbore. Because of its complexity and lack of research approaches, the mechanism and characteristics of annular helical flow by high-pressure jets were never revealed comprehensively. By the computational-fluid-dynamics (CFD) method, the flow field of annular helical flow (such as its generation, continuation, and attenuation) was first manifested. The axial velocity and tangential velocity vary regarding cleaning distance, flow rate, and nozzle assemblies. Furthermore, the dynamic simulation of sandbed sweeping by rotating jets and annular helical flow in a horizontal wellbore was accomplished, and the influences on sweeping efficiency were discussed. Finally, the recommended nozzle assembly and its flow-rate distribution in front jets, lateral jets, and rear jets were provided. This study is beneficial in designing the cleaning tool and in optimizing the hydraulic parameters and operation procedures.

CFD Optimization Analysis of a Cooling Fan for Mining Dump Truck

2013 ◽  
Vol 365-366 ◽  
pp. 388-394
Author(s):  
Jue Yang ◽  
Wei Xing ◽  
Hui Fang Fan
Keyword(s):  
Fluid Dynamics ◽  
Flow Rate ◽  
Static Pressure ◽  
Axial Flow ◽  
Aerodynamic Performance ◽  
Dump Truck ◽  
Blade Number ◽  
Cooling Fan ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

Axial flow fans are widely used in our daily lives such as automotive cooling systems, electronic appliances and air conditioning. The factors that affect the aerodynamic performance of axial flow fans include blade number, fan diameter, hub ratio, blade angle, rotating speed, etc. This paper investigates effects of hub ratio and bladenumber on the aerodynamic performance of the axial flow fan of the radiator of a dump truck we previously designed for mining. With the computational fluid dynamics (CFD) method, the fans operation condition, such as entry static pressure, effective power and flow rate, are numerically simulated with various hub ratios and blade numbers. The results of the numerical simulations are quantitatively analyzed and curves of fans performance changing with hub ratio and blade number are given. An optimization design for the cooling fan is conducted. The results of numerical simulation give conclusion that an increase of 5.6% of the vacuum static pressure and an increase of 3% of flow rate can be obtained when the hub ratio is between 500-600mm, with the same or even less power consumption. The flow rate increment reaches its peak at 8%, while power consumption efficiency is almost linearly increased, when the blade number increases to be in the range of 8 to 10. That is to say when the blade number is between 8 to 10, the fan is apparently making better use of energy. Compared with experimental method, computational fluid dynamics (CFD) method can reduce design circle and lower cost. The CFD results provide guidance to improvement of design efficiency and energy utilization.

scholarly journals Investigation on influences of loose gas on gas-solid flows in a circulating fluidized bed (CFB) reactor using full-loop numerical simulation

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Pengju Huo ◽  
Xiaohong Li ◽  
Yang Liu ◽  
Haiying Qi
Keyword(s):  
Numerical Simulation ◽  
Flow Rate ◽  
Gas Flow ◽  
Circulating Fluidized Bed ◽  
Separation Efficiency ◽  
Circulation Rate ◽  
Solid Mass ◽  
Gas Flow Rate ◽  
Gas Leakage ◽  
Mass Circulation

AbstractThe influences of loose gas on gas-solid flows in a large-scale circulating fluidized bed (CFB) gasification reactor were investigated using full-loop numerical simulation. The two-fluid model was coupled with the QC-energy minimization in multi-scale theory (EMMS) gas-solid drag model to simulate the fluidization in the CFB reactor. Effects of the loose gas flow rate, Q, on the solid mass circulation rate and the cyclone separation efficiency were analyzed. The study found different effects depending on Q: First, the particles in the loop seal and the standpipe tended to become more densely packed with decreasing loose gas flow rate, leading to the reduction in the overall circulation rate. The minimum Q that can affect the solid mass circulation rate is about 2.5% of the fluidized gas flow rate. Second, the sealing gas capability of the particles is enhanced as the loose gas flow rate decreases, which reduces the gas leakage into the cyclones and improves their separation efficiency. The best loose gas flow rates are equal to 2.5% of the fluidized gas flow rate at the various supply positions. In addition, the cyclone separation efficiency is correlated with the gas leakage to predict the separation efficiency during industrial operation.

scholarly journals Effect of hydraulic and geometric factors upon leakage flow rate in pressurized pipes

RBRH ◽  
2021 ◽  
Vol 26 ◽  
Author(s):  
Mayara Francisca da Silva ◽  
Fábio Veríssimo Gonçalves ◽  
Johannes Gérson Janzen
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Rate ◽  
Leakage Flow ◽  
Cfd Simulations ◽  
Mean Velocity ◽  
Leakage Flow Rate ◽  
Geometric Factors ◽  
Leakage Area ◽  
Computational Fluid Dynamics Cfd

ABSTRACT Computational Fluid Dynamics (CFD) simulations of a leakage in a pressurized pipe were undertaken to determine the empirical effects of hydraulic and geometric factors on the leakage flow rate. The results showed that pressure, leakage area and leakage form, influenced the leakage flow rate significantly, while pipe thickness and mean velocity did not influence the leakage flow rate. With relation to the interactions, the effect of pressure upon leakage flow rate depends on leakage area, being stronger for great leakage areas; the effects of leakage area and pressure on leakage flow rate is more pronounced for longitudinal leakages than for circular leakages. Finally, our results suggest that the equations that predict leakage flow rate in pressurized pipes may need a revision.

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