scholarly journals Numerical simulation of dust explosion in the spherical 20l vessel

2015 ◽  
Vol 63 (1) ◽  
pp. 289-293 ◽  
Author(s):  
Z. Salamonowicz ◽  
M. Kotowski ◽  
M. Półka ◽  
W. Barnat
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Combustion Process ◽  
Test Stand ◽  
Maximum Pressure ◽  
Dust Explosion ◽  
Computational Domain ◽  
Dispersion Process ◽  
Dust Dispersion ◽  
Positive Agreement

Abstract The paper presents experimental and numerical validation of the combustion process of coal and flour dust dispersed in a spherical chamber of 20 cubic decimetres volume. The aim of the study is to validate the numerical simulation results in relation to the experimental data obtained on the test stand. To perform the numerical simulations, a Computational Fluid Dynamics code FLUENT was used. Geometry of the computational domain was built in compliance with EN 14460. Numerical simulations were divided into two main steps. The first one consists in a dust dispersion process, where influence of standardized geometry was verified. The second part of numerical simulations investigated dust explosion characteristics in compliance with EN 14034. After several model modifications, outcomes of the numerical analysis shows positive agreement with both, the explosion characteristics for different dust concentration levels and the maximum pressure increase obtained on the test stand.

Visualization Study of Dust Dispersion Process in Siwek 20-L Device for Dust Explosion Test

2014 ◽  
Vol 590 ◽  
pp. 266-270 ◽  
Author(s):  
Bing Du ◽  
Wei Xing Huang ◽  
Nian Sheng Kuai ◽  
Jing Jie Yuan ◽  
Long Liu ◽  
...  
Keyword(s):  
High Speed ◽  
Dust Cloud ◽  
Control Valve ◽  
Processing Technique ◽  
Dust Explosion ◽  
Spherical Vessel ◽  
Dispersion Process ◽  
Visualization System ◽  
Dust Dispersion ◽  
Explosion Test

A visualization method is proposed in order to characterize the dispersion process of dust cloud in Siwek 20-L explosion device. The visualization system consists of a transparent spherical vessel, a dust dispersion device, a high precision control valve and a high-speed camera. Experiment with wheat flour powder indicate that the non-uniformity of dust cloud in space and time can be clearly distinguished based on the frame pictures, as well as the evolution of particles settlement with time after dispersion. Moreover, qualitative analysis based on picture processing technique was carried out to obtain the transmission data of dust cloud from the frame pictures. Results show that the transmission changes rapidly with time and reaches to the minimum value at about 60 ms after dispersion, and with this time, the optimum ignition delay time can be determined for dust explosion test in Siwek 20-L device.

Flow characteristics of dusts dispersed by high-pressure air blast in 20 L chamber

2015 ◽  
Vol 32 (3) ◽  
pp. 742-765 ◽  
Author(s):  
Jiachen Chen ◽  
Qi Zhang
Keyword(s):  
Numerical Simulation ◽  
High Pressure ◽  
Dust Cloud ◽  
Dust Particles ◽  
Dust Explosion ◽  
Air Blast ◽  
Content Type ◽  
Uniform Dispersion ◽  
Dust Dispersion ◽  
Dust Distribution

Purpose – A dust cloud is formed by a high-pressure air blast in dust explosion experiments in the spherical 20 L chamber. The state of the dust cloud has a significant impact on the dust explosion. However, it is difficult to observe the dust distribution in the chamber during the dust dispersion. Numerical simulation was used to examine the dust distribution in the chamber with the rebound nozzle in this work. The paper aims to discuss these issues. Design/methodology/approach – Through a series numerical simulations, the influences of the dust particle size and the pressure for dust dispersion on the have been analyzed, and the results are discussed. Findings – Dust in the spherical 20 L chamber is in the state of very intensifying motion within 30 ms from dispersion starting. Dust in the chamber reaches a uniform state beyond 200 ms. The pressure for dust dispersion should be higher than 0.5 MPa for the aluminum dusts of larger than 50. The higher blast pressure is not always applicable to achieve a uniform dispersion. There is a best blast pressure value for a given dust to achieve a uniform dispersion in the spherical 20 L chamber. Research limitations/implications – Dust cloud generation is essential for understanding dust explosions. Dust cloud deflagration parameters depend on the uniformity and concentration of dusts dispersed by a high-pressure air blast. Numerical simulation was used to examine the multiphase flow of the dust air mixture in this work. Through a series numerical simulations, the influences of the dust particle size and the pressure for dust dispersion on the have been analyzed, and the results are discussed. The data are useful for understanding the basics of dust cloud formation. Practical implications – The data are useful for evaluating dust explosion experimental parameters. Originality/value – Dispersible uniformity has a strong impact on measured parameters of dust explosion in a chamber. However, it is difficult to observe the dust particles distribution during the dispersion. Numerical simulation was used to examine the dust particles distribution and its influencing factors during the dispersion in this work. New finding is: the approach to examine the distribution of dust particles dispersed by a high-pressure blast in a chamber; the variation of dispersible uniformity and its influencing factors when dust is injected into the spherical 20 L chamber by high-pressure air blast.

NUMERICAL SIMULATION OF THE COMPACTION EFFECT DURING SHOCK WAVE € PARTICLE LAYER NUMERICAL SIMULATION OF THE COMPACTION EFFECT DURING SHOCK WAVE-PARTICLE LAYER INTERACTION

2020 ◽  
Author(s):  
YA. E. POROSHYNA ◽  
◽  
P. S. UTKIN ◽  
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Dust Explosion ◽  
Dense Particle ◽  
Layer Interaction ◽  
Particle Layer ◽  
Complex Process ◽  
Impermeable Wall

The problem of shock wave - dense particle layer interaction is a fundamental basis for the study of a more complex process of dust explosion or dust-layered detonation. The work presents results of numerical simulation of the experiment on interaction of an SW with particles layer deposited on the impermeable wall.

Effects of Steam Injection Flow in Burner and Outside Water Tube to the Increasing of Boiler Temperature

2007 ◽  
Vol 7 (1 & 2) ◽  
pp. 120
Author(s):  
M. Djoni Bustan
Keyword(s):  
Human Life ◽  
Combustion Process ◽  
Production Capacity ◽  
Steam Injection ◽  
Oil Refinery ◽  
Specific Enthalpy ◽  
Maximum Pressure ◽  
Injection Flow ◽  
Electrical Generator ◽  
Generator Unit

Energy is an expensive basic need for human life, especially energy from fossils, such as crude oil, gas, and coal. In an oil refinery factory or electrical generator unit, where heat is most dominantly utilized, the boiler is used to generate steam. The main problem in a boiler is its uncompleted combustion process because of the incomplete ratio of air–fuel. This problem is caused by the addition of deposits or sealing inside and outside of the tube fire heater which will reduce the performance of fired heater. The objective of this research is to study the effect of steam flow variation on burner and tubing for increasing heat and temperature as well as the quality of steam. This research used a package boiler B&W series 1986 model which can be seen at an oil refinery factory or steam power electrical generator unit in Indonesia. This package boiler has 50kg/hours steam production capacity, qualified superheated steam, maximum pressure and temperature at 7kgs/cms2 and 700oC. Quantitatively, the achievable heat efficiency which corresponded to the temperature increase caused by the steam injection is 41.25% and the specific enthalpy is 12.07%.

Vibration analysis and combustion parameter evaluation of CI engine based on Fourier Decomposition Method

2021 ◽  
pp. 146808742098819
Author(s):  
Wang Yang ◽  
Cheng Yong
Keyword(s):  
Vibration Analysis ◽  
Decomposition Method ◽  
Combustion Process ◽  
Pressure Rise ◽  
Maximum Pressure ◽  
Vibration Signals ◽  
Loop Control ◽  
Fourier Decomposition ◽  
Surface Vibration ◽  
Rise Rate

As a non-intrusive method for engine working condition detection, the engine surface vibration contains rich information about the combustion process and has great potential for the closed-loop control of engines. However, the measured engine surface vibration signals are usually induced by combustion as well as non-combustion excitations and are difficult to be utilized directly. To evaluate some combustion parameters from engine surface vibration, the tests were carried out on a single-cylinder diesel engine and a new method called Fourier Decomposition Method (FDM) was used to extract combustion induced vibration. Simulated and test results verified the ability of the FDM for engine vibration analysis. Based on the extracted vibration signals, the methods for identifying start of combustion, location of maximum pressure rise rate, and location of peak pressure were proposed. The cycle-by-cycle analysis of the results show that the parameters identified based on vibration and in-cylinder pressure have the similar trends, and it suggests that the proposed FDM-based methods can be used for extracting combustion induced vibrations and identifying the combustion parameters.

scholarly journals Wind shear over the Nice Côte d'Azur airport: case studies

2013 ◽  
Vol 13 (9) ◽  
pp. 2223-2238 ◽  
Author(s):  
A. Boilley ◽  
J.-F. Mahfouf
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Numerical Simulations ◽  
Wind Shear ◽  
Horizontal Wind ◽  
Wind Profiler ◽  
Measurement Campaign ◽  
Wind Lidar ◽  
Real Time Applications ◽  
Wind Shears

Abstract. The Nice Côte d'Azur international airport is subject to horizontal low-level wind shears. Detecting and predicting these hazards is a major concern for aircraft security. A measurement campaign took place over the Nice airport in 2009 including 4 anemometers, 1 wind lidar and 1 wind profiler. Two wind shear events were observed during this measurement campaign. Numerical simulations were carried out with Meso-NH in a configuration compatible with near-real time applications to determine the ability of the numerical model to predict these events and to study the meteorological situations generating an horizontal wind shear. A comparison between numerical simulation and the observation dataset is conducted in this paper.

Numerical Simulation of Premixed Propane/Air Flame Propagation Using a Dynamically Thickened Flame Approach

2013 ◽  
Vol 444-445 ◽  
pp. 1574-1578 ◽  
Author(s):  
Hua Hua Xiao ◽  
Zhan Li Mao ◽  
Wei Guang An ◽  
Qing Song Wang ◽  
Jin Hua Sun
Keyword(s):  
Numerical Simulation ◽  
Flame Propagation ◽  
Numerical Study ◽  
Vortex Motion ◽  
Combustion Process ◽  
Single Step ◽  
Premixed Combustion ◽  
Premixed Flame ◽  
Flame Surface ◽  
Arrhenius Kinetics

A numerical study of premixed propane/air flame propagation in a closed duct is presented. A dynamically thickened flame (TF) method is applied to model the premixed combustion. The reaction of propane in air is taken into account using a single-step global Arrhenius kinetics. It is shown that the premixed flame undergoes four stages of dynamics in the propagation. The formation of tulip flame phenomenon is observed. The pressure during the combustion process grows exponentially at the finger-shape flame stage and then slows down until the formation of tulip shape. After tulip formation the pressure increases quickly again with the increase of the flame surface area. The vortex motion behind the flame front advects the flame into tulip shape. The study indicates that the TF model is quite reliable for the investigation of premixed propane/air flame propagation.

Effects of Natural Gas Compositions on Engine In-Cylinder Process

2015 ◽  
Vol 1092-1093 ◽  
pp. 498-503
Author(s):  
La Xiang ◽  
Yu Ding
Keyword(s):  
Natural Gas ◽  
Alternative Fuels ◽  
Combustion Process ◽  
Engine Performance ◽  
Maximum Temperature ◽  
Maximum Pressure ◽  
Test Bed ◽  
Promising Alternative ◽  
Natural Gas Engines ◽  
Lower Maximum

Natural gas (NG) is one of the most promising alternative fuels of diesel and petrol because of its economics and environmental protection. Generally the NG engine share the similar structure profile with diesel or petrol engine but the combustion characteristics of NG is varied from the fuels, so the investigation of NG engine combustion process receive more attentions from the researchers. In this paper, a zero-dimensional model on the basis of Vibe function is built in the MATLAB/SIMULINK environment. The model provides the prediction of combustion process in natural gas engines, which has been verified by the experimental data in the NG test bed. Furthermore, the influence of NG composition on engine performance is investigated, in which the in-cylinder maximum pressure and temperature and mean indicated pressure are compared using different type NG. It is shown in the results that NG with higher composition of methane results in lower maximum temperature and mean indicated pressure as well as higher maximum pressure.

Stefan Number-Insensitive Numerical Simulation of the Enthalpy Method for Stefan Problems Using the Space-Time Conservation Element and Solution Element Method

2004 ◽  
Author(s):  
Anahita Ayasoufi ◽  
Theo G. Keith ◽  
Ramin K. Rahmani
Keyword(s):  
Numerical Simulation ◽  
Phase Change ◽  
Numerical Simulations ◽  
Latent Heat ◽  
Space Time ◽  
Enthalpy Method ◽  
Stefan Problems ◽  
Stefan Number ◽  
Original Scheme ◽  
Solution Element

An improvement is introduced to the conservation element and solution element (CE/SE) phase change scheme presented previously. The improvement addresses a well known weakness in numerical simulations of the enthalpy method when the Stefan number, (the ratio of sensible to latent heat) is small (less than 0.1). Behavior of the improved scheme, at the limit of small Stefan numbers, is studied and compared with that of the original scheme. It is shown that high dissipative errors, associated with small Stefan numbers, do not occur using the new scheme.

Pneumatic pulsator design as an example of numerical simulations in engineering applications

2012 ◽  
Vol 2 (1) ◽  
Author(s):  
Krzysztof Wołosz ◽  
Jacek Wernik
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Cast Iron ◽  
Numerical Simulations ◽  
Stress Analysis ◽  
Aluminium Alloy ◽  
Loose Material ◽  
Engineering Applications ◽  
Pressure Losses ◽  
Pneumatic Impact

AbstractThe paper presents the part of the investigation that has been carried out in order to develop the pneumatic pulsator which is to be employed as an unblocking device at lose material silo outlets. The part of numerical simulation is reported. The fluid dynamics issues have been outlined which are present during supersonic airflow thought the head of the pulsator. These issues describe the pneumatic impact phenomenon onto the loose material bed present in the silo to which walls the pulsator is assembled. The investigation presented in the paper are industrial applicable and the result is the working prototype of the industrial pneumatic pulsator. The numerical simulation has led to change the piston shape which is moving inside the head of the pulsator, and therefore, to reduce the pressure losses during the airflow. A stress analysis of the pulsator controller body has been carried out while the numerical simulation investigation part of the whole project. The analysis has made possible the change of the controller body material from cast iron to aluminium alloy.

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