Analysis of Relationship between Entropy Generation and Soot Formation in Turbulent Kerosene/Air Jet Diffusion Flames

Bazdidi–Tehrani, Farzad; Abedinejad, Mohammad Sadegh; Mohammadi, Milad

doi:10.1021/acs.energyfuels.9b01671

Cited by 18 publications

(4 citation statements)

References 49 publications

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“…Some extra terms such as the "Reynolds stresses tensors" are generated as a result of the Favre-averaging of the conservation equations. According to several studies [24][25][26][27][28], the realizable k − ε model [29] is presently utilized for modeling the viscous "Reynolds stresses" in a model combustor.…”

Section: Governing Equationsmentioning

confidence: 99%

Analysis of NO Formation and Entropy Generation in a Reactive Flow

Mohammadi

Abedinejad

2022

Aerospace

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A comprehensive investigation of turbulent combustion is accomplished to study the relationship between nitrogen oxide (NO) formation and entropy generation distribution in a non-premixed propane combustion. The radiation heat transfer and combustion are simulated, employing the discrete ordinates model and laminar flamelet model, respectively. A post processing model is employed to estimate the NO formation rate. The present results of NO species formation, mean temperature and velocity are compared with the existing experimental data, and good agreements are obtained. It is shown that the main region of total entropy generation rate and NO formation rate is at the same axial position. The entropy generation distribution may be defined as an index by which the combustion region and main region of NO formation are predicted. However, total entropy generation rate is more sensitive to high temperature (1500–1930 K) than that of NO formation rate. With an increase of 28.7% in temperature, the entropy generation and NO formation rates rise by 900% and 127%, respectively. The occurrence of chemical reactions plays the major role in the generation of entropy.

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Section: Governing Equationsmentioning

confidence: 99%

Analysis of NO Formation and Entropy Generation in a Reactive Flow

Mohammadi

Abedinejad

2022

Aerospace

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“…Furthermore, the effects of non-gray characteristics of three-atom gases (CO 2 and H 2 O), soot particles, and boundary walls on radiation entropy generation were evaluated [ 14 , 15 , 16 ]. Consequently, the relationships between flame temperature, soot formation, local entropy generation, and thermodynamic irreversibility in flames have been quantitatively analyzed [ 17 , 18 ].…”

Section: Introductionmentioning

confidence: 99%

Thermodynamics Irreversibilities Analysis of Oxy-Fuel Diffusion Flames: The Effect of Oxygen Concentration

Yan

Tang

Wang

et al. 2022

Entropy

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In studies on the combustion process, thermodynamic analysis can be used to evaluate the irreversibility of the combustion process and improve energy utilization efficiency. In this paper, the combustion process of a laminar oxy-fuel diffusion flame was simulated, and the entropy generation due to the irreversibilities of the radiation process, the heat conduction and heat convection process, the mass diffusion process, and the chemical reaction process was calculated. The effect of the oxygen concentration in the oxidizer on the entropy generation was analyzed. The results indicated that, as the oxygen concentration in the oxidizer increases, the radiative entropy generation first increases and then decreases, and the convective and conductive entropy generation, the mass diffusion entropy generation, the chemical entropy generation, and the total entropy generation gradually increase.

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“…This is mainly due to the fact that the usage of more sophisticated and detailed models is rather restricted because of the inherently connected high computational costs. This constraint leads to contributions either concentrating on laminar flames [9][10][11], on simplified turbulent configurations using direct numerical simulation (DNS) [12], or on turbulent flames using reduced-order models [11,13,14]. However , the processes generally occurring in combustion systems include exergy losses that vary spatially and temporally.…”

Section: Introductionmentioning

confidence: 99%

Computation of Entropy Production in Stratified Flames Based on Chemistry Tabulation and an Eulerian Transported Probability Density Function Approach

Dreßler

Nicolai

Agrebi

et al. 2022

Entropy

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This contribution presents a straightforward strategy to investigate the entropy production in stratified premixed flames. The modeling approach is grounded on a chemistry tabulation strategy, large eddy simulation, and the Eulerian stochastic field method. This enables a combination of a detailed representation of the chemistry with an advanced model for the turbulence chemistry interaction, which is crucial to compute the various sources of exergy losses in combustion systems. First, using detailed reaction kinetic reference simulations in a simplified laminar stratified premixed flame, it is demonstrated that the tabulated chemistry is a suitable approach to compute the various sources of irreversibilities. Thereafter, the effects of the operating conditions on the entropy production are investigated. For this purpose, two operating conditions of the Darmstadt stratified burner with varying levels of shear have been considered. The investigations reveal that the contribution to the entropy production through mixing emerging from the chemical reaction is much larger than the one caused by the stratification. Moreover, it is shown that a stronger shear, realized through a larger Reynolds number, yields higher entropy production through heat, mixing and viscous dissipation and reduces the share by chemical reaction to the total entropy generated.

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Analysis of Relationship between Entropy Generation and Soot Formation in Turbulent Kerosene/Air Jet Diffusion Flames

Cited by 18 publications

References 49 publications

Analysis of NO Formation and Entropy Generation in a Reactive Flow

Analysis of NO Formation and Entropy Generation in a Reactive Flow

Thermodynamics Irreversibilities Analysis of Oxy-Fuel Diffusion Flames: The Effect of Oxygen Concentration

Computation of Entropy Production in Stratified Flames Based on Chemistry Tabulation and an Eulerian Transported Probability Density Function Approach

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