A 2-D Computational Model Describing the Heat Transfer, Reaction Kinetics and Regeneration Characteristics of a Ceramic Diesel Particulate Trap

1998 ◽  
Author(s):  
Cornelius N. Opris ◽  
John H. Johnson
Keyword(s):  
Heat Transfer ◽  
Computational Model ◽  
Reaction Kinetics ◽  
Transfer Reaction ◽  
Diesel Particulate

A Numerical Investigation Into the Heat Transfer Performance and Particle Dynamics of a Compressible, Highly Mass Loaded, High Reynolds Number, Particle Laden Flow

2021 ◽  
Author(s):  
Kyle Hassan ◽  
Robert F. Kunz ◽  
David Hanson ◽  
Michael Manahan
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Computational Model ◽  
High Reynolds Number ◽  
Heat Transfer Performance ◽  
Particle Dynamics ◽  
Transfer Performance ◽  
Temperature Distributions ◽  
High Reynolds ◽  
Particle Laden Flow

Abstract In this work, we study the heat transfer performance and particle dynamics of a highly mass loaded, compressible, particle-laden flow in a horizontally-oriented pipe using an Eulerian-Eulerian (two-fluid) computational model. An attendant experimental configuration [1] provides the basis for the study. Specifically, a 17 bar co-flow of nitrogen gas and copper powder are modeled with inlet Reynolds numbers of 3×104, 4.5×104, and 6×104 and mass loadings of 0, 0.5, and 1.0. Eight binned particle sizes were modeled to represent the known powder properties. Significant settling of all particle groups are observed leading to asymmetric temperature distributions. Wall and core flow temperature distributions are observed to agree well with measurements. In high Reynolds number cases, the predictions of the multiphase computational model were satisfactorily aligned with the experimental results. Low Reynolds number model predictions were not as consistent with the experimental measurements.

A Study of Heat Transfer Calculation Method of Reactor Vessel Metallic Insulation

2014 ◽  
Author(s):  
Yan Dapeng ◽  
Ying Luo
Keyword(s):  
Heat Transfer ◽  
Computational Model ◽  
Complex Geometry ◽  
Effective Conductivity ◽  
Radiation Heat Transfer ◽  
Reactor Vessel ◽  
View Factor ◽  
Main Mode ◽  
Modified Model ◽  
Test Result

Metallic insulation is commonly used in reactor vessel because of its resistance to radiation and corrosion. Since the main mode of heat loss of reactor vessel is thermal radiation, the ability to prevent radiation heat transfer is important for metallic insulation. But the thermal conductivity of metallic insulation is difficult to calculate owing to their complex geometry. This article uses FLUENT 14.0 to obtain the important parameter “view factor”, and then develops a computational model of effective conductivity of metallic insulation. Heat transfer test of metallic insulation was done, and the numerical simulation of metallic insulation was also performed. Based on results of test and simulation, the computational model is modified. The modified model can fit the test result better. Based on the modified model, the effective conductivity of metallic insulation increases with the increase of temperature of hot side and cold side, among which the temperature of hot side influences more. And when the temperature is high, the effective conductivity increases much faster.

Flow and Chemical Kinetics Simulations of Endothermic Fuels

2003 ◽  
Author(s):  
Thomas A. Ward ◽  
Jamie S. Ervin ◽  
Richard C. Striebich ◽  
Steven Zabarnick
Keyword(s):  
Heat Transfer ◽  
Computational Model ◽  
Chemical Kinetics ◽  
Flow Reactor ◽  
Two Dimensional ◽  
Flow Properties ◽  
Supercritical Regime ◽  
Fuel Flow ◽  
Product Distributions ◽  
Heat Transfer Limit

Advanced aircraft engines are reaching a practical heat transfer limit beyond which the convective heat transfer provided by hydrocarbon fuels is no longer adequate. One solution is to use an endothermic fuel that absorbs heat through chemical reactions. This paper describes the development of a two-dimensional computational model of the heat and mass transport associated with a flowing fuel using a unique global chemical kinetics model. Most past models do not account for changes in the chemical composition of a flowing fuel and also do not adequately predict flow properties in the supercritical regime. The two-dimensional computational model presented here calculates the changing flow properties of a supercritical reacting fuel by use of experimentally derived proportional product distributions. The present calculations are validated by measured experimental data obtained from a flow reactor of mildly cracked n-decane. It is believed that these simulations will assist the fundamental understanding of high temperature fuel flow experiments.

scholarly journals Numerical Prediction of Heat Transfer Characteristics of Nanofluids in a Minichannel Flow

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Arjumand Adil ◽  
Sonam Gupta ◽  
Pradyumna Ghosh
Keyword(s):  
Heat Transfer ◽  
Brownian Motion ◽  
Pressure Drop ◽  
Laminar Flow ◽  
Computational Model ◽  
Flow Regime ◽  
Cfd Simulation ◽  
Computational Results ◽  
Heat Transfer Characteristics ◽  
Simulation Process

CFD simulation of the heat transfer and pressure drop characteristics of different nanofluids in a minichannel flow has been explained using FLUENT version 6.3.26. Different nanofluids with nanoparticles of Al2O3, CuO, SiO2, and TiO2have been used in the simulation process. A comparison of the experimental and computational results has been made for the heat transfer and pressure drop characteristics for the case of Al2O3-water nanofluid for the laminar flow. Also, computations have been made by considering Brownian motion as well as without considering Brownian motion of the nanoparticles. After verification of the computational model with the experimental results for Al2O3-water nanofluid, the simulations were performed for the same experimental readings for different nanofluids in the laminar flow regime to find out the heat transfer and pressure drop characteristics.

CFD Simulation of the Particle Dispersion Behavior and Mass Transfer–Reaction Kinetics in non-Newton Fluid with High Viscosity

2019 ◽  
Vol 17 (7) ◽  
Author(s):  
Le Xie ◽  
Qi-An Wang ◽  
Xian-Jin Luo ◽  
Zheng-Hong Luo
Keyword(s):  
Mass Transfer ◽  
Reaction Kinetics ◽  
Transfer Reaction ◽  
High Viscosity ◽  
Particle Dispersion ◽  
Agitation Speed ◽  
Fluid Viscosity ◽  
Condensation Polymerization ◽  
Cross Model ◽  
Dispersion Behavior

Abstract Solid particle dispersion and chemical reactions in high-viscosity non-Newtonian fluid are commonly encountered in polymerization systems. In this study, an interphase mass transfer model and a finite-rate/eddy-dissipation formulation were integrated into a computational fluid dynamics model to simulate the dispersion behavior of particles and the mass transfer–reaction kinetics in a condensation polymerization-stirred tank reactor. Turbulence fields were obtained using the standard k–ε model and employed to calculate the mixing rate. Cross model was used to characterize the rheological property of the non-Newton fluid. The proposed model was first validated by experimental data in terms of input power. Then, several key operating variables (i.e. agitation speed, viscosity, and particle size) were investigated to evaluate the dispersive mixing performance of the stirred vessel. Simulation showed that a high agitation speed and a low fluid viscosity favored particle dispersions. This study provided useful guidelines for industrial-scale high-viscosity polymerization reactors.

scholarly journals Validity and limitations of simple reaction kinetics to calculate concentrations of organic compounds from ion counts in PTR-MS

2019 ◽  
Vol 12 (11) ◽  
pp. 6193-6208 ◽  
Author(s):  
Rupert Holzinger ◽  
W. Joe F. Acton ◽  
William J. Bloss ◽  
Martin Breitenlechner ◽  
Leigh R. Crilley ◽  
...  
Keyword(s):  
Proton Transfer ◽  
Reaction Kinetics ◽  
Transfer Reaction ◽  
Performance Status ◽  
Calibration Method ◽  
Proton Transfer Reaction ◽  
Rural Site ◽  
Water Molecules ◽  
Simple Reaction ◽  
Wide Range

Abstract. In September 2017, we conducted a proton-transfer-reaction mass-spectrometry (PTR-MS) intercomparison campaign at the CESAR observatory, a rural site in the central Netherlands near the village of Cabauw. Nine research groups deployed a total of 11 instruments covering a wide range of instrument types and performance. We applied a new calibration method based on fast injection of a gas standard through a sample loop. This approach allows calibrations on timescales of seconds, and within a few minutes an automated sequence can be run allowing one to retrieve diagnostic parameters that indicate the performance status. We developed a method to retrieve the mass-dependent transmission from the fast calibrations, which is an essential characteristic of PTR-MS instruments, limiting the potential to calculate concentrations based on counting statistics and simple reaction kinetics in the reactor/drift tube. Our measurements show that PTR-MS instruments follow the simple reaction kinetics if operated in the standard range for pressures and temperature of the reaction chamber (i.e. 1–4 mbar, 30–120∘, respectively), as well as a reduced field strength E∕N in the range of 100–160 Td. If artefacts can be ruled out, it becomes possible to quantify the signals of uncalibrated organics with accuracies better than ±30 %. The simple reaction kinetics approach produces less accurate results at E∕N levels below 100 Td, because significant fractions of primary ions form water hydronium clusters. Deprotonation through reactive collisions of protonated organics with water molecules needs to be considered when the collision energy is a substantial fraction of the exoergicity of the proton transfer reaction and/or if protonated organics undergo many collisions with water molecules.

A study on mass transfer–reaction kinetics of NO absorption by using UV/H2O2/NaOH process

Fuel ◽  
2013 ◽  
Vol 108 ◽  
pp. 254-260 ◽  
Author(s):  
Yangxian Liu ◽  
Jianfeng Pan ◽  
Aikun Tang ◽  
Qian Wang
Keyword(s):  
Mass Transfer ◽  
Reaction Kinetics ◽  
Transfer Reaction ◽  
Kinetics Of ◽  
No Absorption
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