Numerical study on forced convection in the exhaust problem using the spectral line-based weighted sum of gray gases model

Atashafrooz, Meysam; Asadi, Tahereh; Yan, Wei‐Mon

doi:10.1016/j.ijheatmasstransfer.2020.119837

Cited by 8 publications

(3 citation statements)

References 61 publications

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“…The albedo coefficient, optical thickness, and radiation-conduction parameters have an influence on the heat transfer behavior of the system [23,24]. Among the six radiation models provided by Fluent, only the P1 model and DO (discrete ordinate) model can be used to simulate the radiation between the solid phase and gas phase.…”

Section: Radiation Modelmentioning

confidence: 99%

The Co-Processing Combustion Characteristics of Municipal Sludge within an Industrial Cement Decomposition Furnace via Computational Fluid Dynamics

Zhu,

Mao,

Liu

et al. 2024

Mathematics

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Dealing with municipal sludge in an effective way is crucial for urban development and environmental protection. Co-processing the sludge by burning it in a decomposition furnace in the cement production line has been found to be a viable solution. This work aims to analyze the effects of the co-disposal of municipal sludge on the decomposition reactions and NOx emissions in the decomposing furnaces. Specifically, a practical 6000 t/d decomposition furnace was taken as the research object. To achieve this, ANSYS FLUENT with a UDF (user-defined function) was applied to establish a numerical model coupling the limestone decomposition reaction, fuel combustion, and NOx generation and reduction reactions. The flow, temperature, and component field distributions within the furnace with no sludge were firstly simulated with this model. Compared with site test results, the model was validated. Then, with sludge involved, the structure and operation parameters of the decomposition furnace for the co-disposal of municipal sludge were investigated by simulating the flow field, temperature field, and component field distributions. Parametric studies were carried out in three perspectives, i.e., sludge mixing ratio, preheating furnace arrangement height, and sludge particle size. The results show that all three aspects have great importance in the discomposing process. A set of preferable values, including a sludge mixing ratio of 10%, preheating furnace height of 21.5 m, and sludge particle diameter of 1.0 mm, was obtained, which resulted in a raw material decomposition rate of 89.9% and a NO volume fraction of 251 ppm at the furnace outlet.

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Section: Radiation Modelmentioning

confidence: 99%

The Co-Processing Combustion Characteristics of Municipal Sludge within an Industrial Cement Decomposition Furnace via Computational Fluid Dynamics

Zhu,

Mao,

Liu

et al. 2024

Mathematics

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“…Niemann et al [23] studied the impact of buoyancy effects on the velocity field and on turbulent heat transfer in the mixed regime by comparing two simulations, one with the buoyancy term removed from the equations and the other with a Richardson number of 0.338. On an inclined step in an inclined duct, Atashafrooz [24] presented the influence of buoyancy force on nanofluid flow in mixed MHD convection and entropy generation where the interaction of several parameters is studied, in an abruptly contracting duct [25], in a trapezoidal recess [26], and in three-dimensional forced convection [27], radiative heat transfer plays an important role in thermal behavior, so considering the interactions between the different radiative and convective (or conductive) heat transfer mechanisms can improve simulation precision [28][29][30][31][32][33].…”

Section: Introductionmentioning

confidence: 99%

Effect of the inclination angle of finned cylinder over a BFS on the MHD behavior in the presence of a nanofluid

Derbal

Bouzit

2022

Metall Mater Eng

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The present numerical study is based on the forced magnetohydrodynamic (MHD) convection of a ferrofluid through a backward facing step (BFS). A cylinder with two fixed fins and fixed dimensions is implanted inside fluid. The dimensionless governing equations have been solved using the multigrid finite element method. Several parameters were considered, such as the Hartmann number 0≤ Ha ≤100, the magnetic field inclination angle 0°≤ ɣ ≤90°, the Reynolds number 10≤ Re ≤200, the nanoparticle volume fraction 0%≤ φ ≤10%, and the fins inclination angle 0°≤ a ≤180°. The results have shown that the presence of the fins improves the heat transfer, especially at the position a = 90° where the Nuave number increases with a ratio of 113% for Re = 200.

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“…They also found that the exergy loss seems to be independent of the heat source location. Atashafrooz et al (2020) investigated the impact of radiation on forced convection flow in the exhaust problem by comparing the differences between the spectral line WSGG and gray models. Torres et al (2020) used a CFD simulation to understand the characteristics of mixed convection and radiation and to predict thermal losses from an isothermal bladed structure.…”

Section: Introductionmentioning

confidence: 99%

Interaction of mixed convection with non-gray gas radiation in a partially heated horizontal pipe: entropy generation analysis

Mazgar

Jarray

Hajji

et al. 2021

HFF

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Purpose This paper aims to numerically analyze the effect of non-gray gas radiation on mixed convection in a horizontal circular duct with isothermal partial heating from the sidewall. The influence of heater location on heat transfer, fluid flow and entropy generation is given and discussed in this study. Design/methodology/approach The numerical computation of heat transfer and fluid flow has been developed by the commercial finite element software COMSOL Multiphysics. Radiation code is developed based on the T10 Ray-Tracing method, and the radiative properties of the medium are computed based on the statistical narrow band correlated-k model. Findings The obtained results depicted that the radiation considerably contributes to the temperature homogenization of the gas. The findings highlight the impact of the heater location on swirling flow. It is also shown that the laterally heating process provides better energy efficiency than heating from the top of the enclosure. Originality/value This study is performed to improve heat transfer and to minimize entropy generation. Therefore, it is conceivable to improve the model design of industrial applications.

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Numerical study on forced convection in the exhaust problem using the spectral line-based weighted sum of gray gases model

Cited by 8 publications

References 61 publications

The Co-Processing Combustion Characteristics of Municipal Sludge within an Industrial Cement Decomposition Furnace via Computational Fluid Dynamics

The Co-Processing Combustion Characteristics of Municipal Sludge within an Industrial Cement Decomposition Furnace via Computational Fluid Dynamics

Effect of the inclination angle of finned cylinder over a BFS on the MHD behavior in the presence of a nanofluid

Interaction of mixed convection with non-gray gas radiation in a partially heated horizontal pipe: entropy generation analysis

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