A New Modeling Approach to Reacting Dispersed Flow in Smelting Cyclones

2000 ◽  
Author(s):  
M. Modigell ◽  
M. Weng
Keyword(s):  
Experimental Data ◽  
Flow Field ◽  
Gas Flow ◽  
Equilibrium Calculation ◽  
New Approach ◽  
Reaction Progress ◽  
Numeric Simulation ◽  
Thermodynamic Equilibrium Calculation ◽  
Simulation Results ◽  
Comparison With Experimental Data

Abstract The present paper proposes a new approach to analyse the conversion of complexly composed particles that are dispersed in a cyclone gas flow at high temperatures. The numeric simulation of flow field and particle trajectories is coupled with a thermodynamic equilibrium calculation which describes the particle reaction progress. First simulation results and the comparison with experimental data are shown in this paper.

Numerical Simulations of the Mixing Uniformity of Tracer Gas and Air in 90 Degree Elbow Duct

2011 ◽  
Vol 347-353 ◽  
pp. 3207-3210
Author(s):  
Ming Guang Zheng ◽  
Xian Yang Zeng ◽  
Zuo He Chi ◽  
Gong Gang Sun ◽  
Guang Xue Zhang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Gas Flow ◽  
Tracer Gas ◽  
Data Simulation ◽  
Online Calibration ◽  
Air Mixing ◽  
Point Discharge ◽  
Simulation Results ◽  
Better Than

To investigate the mixing uniformity between tracer gas and gas stream in the duct, numerical simulations of the CO tracer gas and air mixing in a 300mm diameter and 90 degree elbow duct were performed on the commercial CFD software FLUENT, and the comparisons between the simulation results and experimental data were analyzed. Tracer gas is injected by 5-point discharge, the mixing uniformity between tracer gas and air is better than that of 1-point discharge. The results indicated that the tracer gas concentrations of simulations were agreed with the experimental data. Simulation results could provide a valuable guidance for gas flow rate measurement and online calibration for gas flowmeter with tracer gas technique.

The Experimental Study and Numerical Simulation of the Gas Flow Field in the Cold Storage of Procambarus Clarkii

2014 ◽  
Vol 716-717 ◽  
pp. 780-784
Author(s):  
Shuo Li ◽  
Shu Cai Wang ◽  
Fang Cheng ◽  
Gao Bing Xia
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Cold Storage ◽  
Gas Flow ◽  
Procambarus Clarkii ◽  
Freezing Process ◽  
Uniform Temperature ◽  
Design And Optimization ◽  
Computational Fluid Dynamics Cfd ◽  
Simulation Results

The gas flow in the cold storage plays a very important role in the effect of cold storages of procambarus clarkii. Only the reasonable gas flow ensures the uniform temperature field.The paper uses the technique of computational fluid dynamics (CFD) to conduct the numerical simulation of the flow field and finds out the law of the distribution of the temperature field,on the basis of which the numerical simulation of non steady state of the freezing process of the frozen products is carried out.The experiments prove that the simulation results can better reflect the reality,and show that CFD tools can play an important role in the design and optimization of cold storages.

A Simplified Numerical Approach to Characterize the Thermal Response of a Moving Bed Solar Reactor

2021 ◽  
Author(s):  
Assaad Al Sahlani ◽  
Kelvin Randhir ◽  
Nesrin Ozalp ◽  
James Klausner
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Energy Storage ◽  
Solid Particle ◽  
Gas Flow ◽  
Plug Flow ◽  
Fixed Bed ◽  
Flow Rates ◽  
Proposed Model ◽  
Simulation Results

Abstract Concentrated solar thermochemical storage in the form of a zero-emission fuel is a promising option to produce long-duration energy storage. The production of solar fuel can occur within a cylindrical cavity chemical reactor that captures concentrated solar radiation from a solar field. A heat transfer model of a tubular plug-flow reactor is presented. Experimental data from a fixed bed tubular reactor are used for model comparison. The system consists of an externally heated tube with counter-current flowing gas and moving solid particles as the heated media. The proposed model simulates the dynamic behavior of temperature profiles of the tube wall, gas, and particles under various gas flow rates and residence times. The heat transfer between gas-wall, solid particle-wall, gas-solid particle, are numerically studied. The model is compared with experiments using a 4 kW furnace with a 150 mm heating zone surrounding a horizontal alumina tube (reactor) with 50.8 mm OD and a thickness of 3.175 mm. Solid fixed particles of magnesium manganese oxide (MgMn2O4) with the size of 1 mm are packed within the length of 250 mm at the center of the tube length. Simulation results are assessed with respect to fixed bed experimental data for four different gas flow rates, namely 5, 10, 15, 20 standard liters per minute of air, and furnace temperatures in the range of 200 to 1200 °C. The simulation results showed good agreement with maximum steady state error that is less than 6% of those obtained from the experiments among all runs. The proposed model can be implemented as a low-order physical model for the control of temperature inside plug-flow reactors for thermochemical energy storage (TCES) applications.

STATISTICAL MODELING OF DIFFUSION COEFFICIENT IN THE MASS HETEROGENEOUS STRUCTURES

2003 ◽  
Vol 17 (11) ◽  
pp. 2313-2323 ◽  
Author(s):  
Lj. MAŠKOVIĆ ◽  
R. VUJOVIĆ ◽  
B. S. TOŠIĆ ◽  
E. MOHORA
Keyword(s):  
Experimental Data ◽  
Diffusion Coefficient ◽  
Statistical Modeling ◽  
Coupled Oscillators ◽  
Energy Levels ◽  
Mass Dependence ◽  
Statistical Probability ◽  
New Approach ◽  
Heterogeneous Structures ◽  
Comparison With Experimental Data

The statistical modeling was used in the analysis of structures containing heterogeneous masses. The statistical probability of a system of coupled oscillators was found taking into account the mass dependence of energy levels. It is essentially a new approach. Both the low as well as high temperature expressions for diffusion coefficient were found. Comparison with experimental data gave satisfactory agreement.

Numerical Study of the Gas Flow in the Swirl Tube

2012 ◽  
Vol 550-553 ◽  
pp. 3194-3200
Author(s):  
Guang Cai Gao ◽  
Jian Jun Wang ◽  
You Hai Jin
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Reynolds Stress ◽  
Experimental Measurement ◽  
Gas Flow ◽  
Numerical Study ◽  
Separation Performance ◽  
Turbulent Model ◽  
Simulation Results ◽  
Good Agreement

The gas flow field in the swirl tube was studied by experimental measurement and numerical simulation. The results show that the simulation results based on the Reynolds stress turbulent model is in good agreement with the measured results probed by the five orifice Pitot-tube. Meantime, it is analyzed that there is short cut stream at the end of the exit tube, and at the dust discharge jaws, the particles are prone to be re-entrained from the hopper. All results above provide a base for further research on the optimization of the structure and the improvement of the separation performance of the swirl tube.

scholarly journals Effect of the Soft and Hard Interbedded Layers of Bedrock on the Mechanical Characteristics of Stabilizing Piles

2020 ◽  
Vol 10 (14) ◽  
pp. 4760
Author(s):  
Manman Dong ◽  
Liangqing Wang ◽  
Babak Shahbodagh ◽  
Xi Du ◽  
Shan Deng ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mechanical Characteristics ◽  
Element Model ◽  
Discrete Element ◽  
Discrete Element Model ◽  
Maximum Displacement ◽  
Stabilizing Piles ◽  
Simulation Results ◽  
Dip Angle ◽  
Comparison With Experimental Data

In this paper, the mechanical characteristics of stabilizing piles embedded in layered bedrocks are studied both experimentally and numerically. The influence of soft and hard interbedded layers in the structure of the bedrock on the mechanical characteristics of stabilizing piles is particularly investigated. The discrete element method is used to numerically investigate the response of the stabilizing piles embedded in composite and inclined bedrocks. The simulation results and comparison with experimental data are presented to demonstrate the effectiveness and accuracy of the discrete element model. As the dip angle of the soft/hard interbedded bedrock layers increases from 0° to 45°, it is observed that the displacement of the embedded section of the stabilizing pile increases and reaches the maximum displacement at 45°. In the range of 45° to 75°, the influence of the dip angle of the layered bedrock on the displacement of the embedded section of the pile is gradually reduced.

Comparing 2D and 3D numerical simulation results of gas flow velocity in convection reflow oven

2014 ◽  
Vol 26 (4) ◽  
pp. 223-230 ◽  
Author(s):  
Balázs Illés
Keyword(s):  
Heat Transfer ◽  
Flow Field ◽  
Flow Velocity ◽  
Gas Flow ◽  
Content Type ◽  
Simulation Results ◽  
2D And 3D ◽  
Gas Flow Velocity ◽  
2D Model ◽  
Gas Flow Field

Purpose – This paper aims to compare and study two-dimensional (2D) and three-dimensional (3D) computational fluid dynamics simulation results of gas flow velocity in a convection reflow oven and show the differences of the different modeling aspects. With the spread of finer surface-mounted devices, it is important to understand convection reflow soldering technology more deeply. Design/methodology/approach – Convection reflow ovens are divided into zones. Every zone contains an upper and a lower nozzle-matrix. The gas flow velocity field is one of the most important parameters of the local heat transfer in the oven. It is not possible to examine the gas flow field with classical experimental methods due to the extreme circumstances in the reflow oven. Therefore, numerical simulations are necessary. Findings – The heat transfer changes highly along the moving direction of the assembly, and it is nearly homogeneous along the traverse direction of the zones. The gas flow velocity values of the 2D model are too high due to the geometrical distortions of the 2D model. On the other hand, the calculated flow field of the 2D model is more accurate than in the 3D model due to the finer mesh. Research limitations/implications – Investigating the effects of tall components on a printed wiring board inside the gas flow field and further analysis of the mesh size effect on the models. Practical implications – The presented results can be useful during the design of a simulation study in a reflow oven (or in similar processes). Originality/value – The presented results provide a completely novel approach from the aspect of 2D and 3D simulations of a convection reflow oven. The results also reveal the heat transfer differences.

A SIMPLIFIED NUMERICAL APPROACH TO CHARACTERIZE THE THERMAL RESPONSE OF A MOVING BED SOLAR REACTOR

2021 ◽  
pp. 1-6
Author(s):  
Assaad Alsahlani ◽  
Kelvin Randhir ◽  
Nesrin Ozalp ◽  
James Klausner
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Solid Particle ◽  
Gas Flow ◽  
Plug Flow ◽  
Fixed Bed ◽  
Tube Length ◽  
Flow Rates ◽  
Proposed Model ◽  
Simulation Results

Abstract In this paper, heat transfer model of a tubular plug-flow reactor designed and manufactured for a solar fuel production is presented. Experimental data collected from a fixed bed tubular reactor testing are used for model comparison. The system consists of an externally heated tube with counter-current flowing gas and moving solid particles as the heated media. The proposed model simulates the dynamic behavior of temperature profiles of the tube wall, gas, and particles under various gas flow rates and residence times. The heat transfer between gas-wall, solid particle-wall, and gas-solid particle are numerically studied. The model results are compared with the results of experiments done using a 4 kW furnace with a 150 mm heating zone surrounding a horizontal alumina tube (reactor) with 50.8 mm outer diameter and thickness of 3.175 mm. Solid fixed particles of MgMn2O4 with the size of 1 mm are packed within length of 250 mm at the center of the tube length. Simulation results are assessed with respect to fixed bed experimental data for four different gas flow rates, namely 5, 10, 15, 20 standard liters per minute of air, and furnace temperatures in the range of 200 to 1200 °C. The simulation results showed good agreement with maximum steady state error that is less than 6% of those obtained from the experiments for all runs. The proposed model can be implemented as a low-order physical model for the control of temperature inside plug-flow reactors.

Numerical Simulation and Impeller Optimization of a Centrifugal Pump

2012 ◽  
Vol 472-475 ◽  
pp. 2195-2198 ◽  
Author(s):  
Shao Ping Zhou ◽  
Pei Wen Lv ◽  
Xiao Xia Ding ◽  
Yong Sheng Su ◽  
De Quan Chen
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Flow Field ◽  
Centrifugal Pump ◽  
Turbulence Model ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Three Dimensional Flow ◽  
Field Simulation ◽  
Simulation Results

The three-dimensional flow field simulation of a centrifugal pump was presented by using commercial CFD code. In order to study the most suitable turbulence model, the three known turbulence models of Standard k-ε, RNG k-ε, Realizable k-ε were applied to simulate the flow field of the MJ125-100 centrifugal pump and predict the performance of the pump. The simulation results of head and efficiency were compared with available experimental data, and the comparison showed that the result of the numerical simulation by RNG k-ε model had the best agreement. Additionally, the effect of number of blades on the efficiency of pump was studied. The number of blades was changed from 4 to 7. The results showed that the impeller with 7 blades had the highest efficiency.

Sign in / Sign up

Export Citation Format

Share Document