Numerical Simulation on the Influence of Flammable Gas Concentration on Explosion Peak Pressure

2014 ◽  
Vol 1010-1012 ◽  
pp. 1531-1534
Author(s):  
Xiao Feng Ma
Keyword(s):  
Numerical Simulation ◽  
Peak Pressure ◽  
Gas Concentration ◽  
Explosion Pressure ◽  
Flammable Gas ◽  
Explosion Overpressure ◽  
Fluent Software

This paper simulates the alternation of the maximum explosion overpressure on the different condition of the concentration based on the fluent software. The results show the maximum explosion overpressure increases in the earlier stage and then decreases in the later stage because of the different flammable gas concentration: the maximum explosion overpressure enhanced in 6% gas concentration and drops in 12% gas concentration; it augments in 6% gas concentration and drops in 12% gas concentration with the joining of the hydrogen; the explosion pressure peaked just at the 9% concentration of the flammable gas.

Study on Gas Flow Law in Goaf of Huangling No.1 Mine Fully-Mechanized Face

2014 ◽  
Vol 1010-1012 ◽  
pp. 1548-1553
Author(s):  
Tian Xuan Hao ◽  
Meng Liu
Keyword(s):  
Numerical Simulation ◽  
Gas Flow ◽  
Sampling Method ◽  
Concentration Field ◽  
High Fracture ◽  
Gas Concentration ◽  
Working Face ◽  
Fluent Software ◽  
Gas Control ◽  
Important Basis

The gas concentration field in goaf of Huangling No.1 Mine 304 fully-mechanized face was simulated numerically by FLUENT software with high fracture drilling or not. The results of numerical simulation were confirmed by fixed sampling method of immersed tube in goaf. Thus, the law of gas concentration field was gained, which provides the important basis for gas control of working face.

scholarly journals NUMERICAL SIMULATION ON THE EFFECT OF CONCENTRATION ON PREMIXED CH4/CO2/AIR EXPLOSION CHARACTERISTICS

2019 ◽  
Vol 5 (1) ◽  
pp. 39-47
Author(s):  
Nur Aqidah Muhammad Harinder Khan ◽  
Siti Zubaidah Sulaiman ◽  
Izirwan Izhab ◽  
Siti Kholijah Abdul Mudalip ◽  
Rohaida Che Man ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Maximum Rate ◽  
Pressure Rise ◽  
Spherical Vessel ◽  
Explosion Pressure ◽  
Flame Acceleration ◽  
Explosion Overpressure ◽  
Pressure Development ◽  
Air Explosion ◽  
Rich Mixtures

In this study, a numerical simulation on the premixed CH4/CO2/Air (methane/carbon dioxide/air) mixture explosion characteristics was conducted by using the Flame Acceleration Simulator (FLACs) software. The domain used in the 20 L spherical vessel with 0.808 m diameter. The effect of various equivalence ratios on the explosion characteristics such as the explosion pressure, Pex, maximum explosion overpressure, Pmax, the maximum rate of the pressure rise, (dP/dt)max and gas deflagration index, KG, were studied. For this purpose, the mixture concentrations range from equivalence ratio (ER) 0.8 to 1.5 (9.6 to 18% vol/vol) were considered. From this study, the explosion pressure, Pex, maximum explosion overpressure, Pmax, and the maximum rate of pressure rise, (dP/dt)max, at various ER was the maximum at a slightly rich concentration (ER=1.2). At lean and rich mixtures, the Pex, Pmax, (dP/dt)max and KG decreases. It can be said that, at ER=1.2, the role of thermal-diffusive instability and its effect on the flame speed during the pressure development process had causes the diffused methane, CH4, to react further into the flame front, which significantly increases the mixture mass burning rate and flame was also found to propagates the fastest at ER=1.2 due to the incompletecombustion process caused by the insufficient and excess CH4 present in the lean and rich mixtures. The CH4/CO2/air mixtures studied in this study were also found to have the highest level of hazard potential when exploded.

The Influence of the Convective Terms Discretization Scheme on the Simulation Results of Architectural Numerical Wind Tunnel

2012 ◽  
Vol 204-208 ◽  
pp. 4884-4887
Author(s):  
Jian Feng Wu ◽  
Cai Hua Wang ◽  
Chang Li Song
Keyword(s):  
Numerical Simulation ◽  
Wind Tunnel ◽  
Building Structures ◽  
Discretization Scheme ◽  
Shape Coefficient ◽  
Fluent Software ◽  
Actual Operation ◽  
Simulation Results ◽  
Load Shape ◽  
Numerical Wind Tunnel Method

The numerical simulation of construction is to obtain the desired accuracy. It depends on the theoretical basis of the calculator and selection of the various important factors in the actual operation. For this problem, this paper adopting the current code for the design of building structures as the comparison standard, using the FLUENT software, taking the numerical simulation results of a high building’s wind load shape coefficient of for example, discussing the influence of four kinds of the convective terms discretization scheme, respectively the first-order upwind, the second order upwind , power law and Quadratic upwind interpolation for convective kinematics, on the simulation results of architectural numerical wind tunnel, provides the reference for the rational use of numerical wind tunnel method.

Numerical Simulation of High-Aspect-Ratio Micro-Hole Electroforming with External Magnetic Field

2010 ◽  
Vol 42 ◽  
pp. 13-16
Author(s):  
Wei Li ◽  
Ping Mei Ming ◽  
Wu Ji Jiang ◽  
Yin Ding Lv
Keyword(s):  
Magnetic Field ◽  
Numerical Simulation ◽  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Flow State ◽  
Cathode Electrode ◽  
Micro Hole ◽  
Fluent Software ◽  
The Magnetic Field ◽  
Enhance Mass

In this paper, the influences of applied magnetic field on flow state during electroforming of the high-aspect-ratio (HAR) blind micro-hole were numerically analyzed using the Fluent software. The results showed that, when microelectroforming of nickel without external agitation, three vortexes could form due to the magnetohydrodynamic (MHD) effect within the HAR micro-hole with magnetic field in parallel to cathode-electrode surface, and the flow rate in the micro-hole increased with the increase of the magnetic field and current density. The MHD effect helped to enhance mass transfer during the microelectroforming of HAR microstructures.

scholarly journals NUMERICAL SIMULATION OF AIRFLOW AROUND VEHICLE MODELS

2018 ◽  
Vol 56 (3) ◽  
pp. 370
Author(s):  
Nguyen Van Thang ◽  
Ha Tien Vinh ◽  
Bui Dinh Tri ◽  
Nguyen Duy Trong
Keyword(s):  
Numerical Simulation ◽  
Kinetic Energy ◽  
Three Dimensional ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Forces ◽  
Dissipation Energy ◽  
Ansys Fluent ◽  
Car Model ◽  
Airflow Field ◽  
Fluent Software

This article carries out the numerical simulation of airflow over three dimensional car models using ANSYS Fluent software. The calculations have been performed by using realizable k-e turbulence model. The external airflow field of the simplified BMV M6 model with or without a wing is simulated. Several aerodynamic characteristics such as pressure distribution, velocity contours, velocity vectors, streamlines, turbulence kinetic energy and turbulence dissipation energy are analyzed in this study. The aerodynamic forces acting on the car model is calculated and compared with other authors.

scholarly journals Numerical simulation and experimental research of cavitation nozzle based on equation curve

2021 ◽  
Author(s):  
Lifu Wang ◽  
Dongyan Shi ◽  
Zhixun Yang ◽  
Guangliang Li ◽  
Chunlong Ma ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Reynolds Number ◽  
Flow Field ◽  
High Speed ◽  
Quadratic Equation ◽  
Outer Contour ◽  
Study Results ◽  
Fluent Software ◽  
The Impact ◽  
Better Than

Abstract To further investigate and improve the cleaning ability of the cavitation nozzle, this paper proposes a new model that is based on the Helmholtz nozzle and with the quadratic equation curve as the outer contour of the cavitation chamber. First, the numerical simulation of the flow field in the nozzle chamber was conducted using FLUENT software to analyze and compare the impact of the curve parameters and Reynolds number on the cleaning effect. Next, the flow field was captured by a high-speed camera in order to study the cavitation cycle and evolution process. Then, experiments were performed to compare the cleaning effect of the new nozzle with that of the Helmholtz nozzle. The study results demonstrate that effective cavitation does not occur when the diameter of the cavitation chamber is too large. For the new nozzle, with the increase of the Reynolds number, the degree of cavitation in the chamber first increases and then decreases; the cleaning effect is much better than that of a traditional Helmholtz nozzle under the same conditions; the nozzle has the best cleaning effect for the stand-off distance of 300 mm.

scholarly journals Numerical Simulation of Diffusion Absorption Refrigerator

2021 ◽  
Vol 233 ◽  
pp. 01044
Author(s):  
Guoyan Zhang ◽  
Shengyong Liu ◽  
Jie Lu ◽  
Jiong Wang ◽  
Yongtao Ma
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Gas Phase ◽  
Radial Direction ◽  
Tube Length ◽  
Lifting Capacity ◽  
Fluent Software ◽  
Lower Temperature ◽  
Absorption Refrigerator ◽  
Diffusion Absorption

Based on Fluent software, a mathematical model of thermosyphon pump is established and numerical simulation is carried out to study the influence of riser tube length, tube diameter and immersion ratio on liquid lifting capacity and efficiency. The results showed that: the liquid lifting volume increased with the increase of immersion ratio, whereas the lifting efficiency showed a trend of increasing followed by decreasing. The highest lifting efficiency for a 340mm long, 6mm diameter riser achieved when the immersion ratio is 0.35. With the increasing of the height in riser, the velocity of the gas phase close to the wall in the thermosyphon pump was higher than the velocity along the radial direction. In order to enhance fluid interchange, corners of the refrigeration box were designed to be arc-shaped with a higher corner speed and lower temperature.

The Numerical Simulation of Heat and Mass Transfer in Porous Medium

2011 ◽  
Vol 71-78 ◽  
pp. 4658-4661
Author(s):  
Ling Wang ◽  
Jian Zhang
Keyword(s):  
Numerical Simulation ◽  
Mass Transfer ◽  
Porous Medium ◽  
Heat And Mass Transfer ◽  
Fluent Software

Simulate the heat and mass transfer in 2D cases using fluent software and analyse the results of simulation. Summarize the reasons of neglecting the nature convection under the small Ra number, Furthermore state good thermal retardation properties of porous medium in building.

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