Entropy generation in turbulent natural convection due to internal heat generation

Chen, Sheng; Krafczyk, Manfred

doi:10.1016/j.ijthermalsci.2009.02.012

Cited by 65 publications

(51 citation statements)

References 42 publications

(93 reference statements)

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“…Due to the importance of combustion phenomena, one can find a number of LB papers in literature [50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67]. The pioneering LB model for combustion systems was given by Succi et al [50] in 1997.…”

Section: Introductionmentioning

confidence: 99%

Multiple-relaxation-time lattice Boltzmann kinetic model for combustion

et al. 2015

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To probe both the Hydrodynamic Non-Equilibrium (HNE) and Thermodynamic NonEquilibrium (TNE) in the combustion process, a two-dimensional Multiple-Relaxation-Time (MRT) version of Lattice Boltzmann Kinetic Model(LBKM) for combustion phenomena is presented. The chemical energy released in the progress of combustion is dynamically coupled into the system by adding a chemical term to the LB kinetic equation. Beside describing the evolutions of the conserved quantities, the density, momentum and energy, which are what the Navier-Stokes model describes, the MRT-LBKM presents also a coarse-grained description on the evolutions of some non-conserved quantities. The current model works for both subsonic and supersonic flows with or without chemical reaction. In this model both the specific-heat ratio and the Prandtl number are flexible, the TNE effects are naturally presented in each simulation step. The model is verified and validated via well-known benchmark tests. As an initial application, various non-equilibrium behaviours, including the complex interplays between various HNEs, between various TNEs and between the HNE and TNE, around the detonation wave in the unsteady and steady one-dimensional detonation processes are preliminarily probed. It is found that the system viscosity (or heat conductivity) decreases the local TNE, but increase the global TNE around the detonation wave, that even locally, the system viscosity (or heat conductivity) results in two kinds of competing trends, to increase and to decrease the TNE effects. The physical reason is that the viscosity (or heat conductivity) takes part in both the thermodynamic and hydrodynamic responses.

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Section: Introductionmentioning

confidence: 99%

Multiple-relaxation-time lattice Boltzmann kinetic model for combustion

et al. 2015

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“…As with the single-phase system, this model has been validated over many years by repeated analyses and comparisons with analytical and experimental results [14,16,18,44,45]. It has been successfully applied to a variety of thermal flow problems including natural convection [14,18,44,[46][47][48][49][50], turbulent convection [51][52][53][54], thermal channel flows [14,40,55,56] and more complex systems involving multiple phases and phase change [57][58][59][60][61][62][63][64][65].…”

Section: Thermohydrodynamicsmentioning

confidence: 99%

A Non-Isothermal Chemical Lattice Boltzmann Model Incorporating Thermal Reaction Kinetics and Enthalpy Changes

Bartlett

2017

Computation

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Abstract:The lattice Boltzmann method is an efficient computational fluid dynamics technique that can accurately model a broad range of complex systems. As well as single-phase fluids, it can simulate thermohydrodynamic systems and passive scalar advection. In recent years, it also gained attention as a means of simulating chemical phenomena, as interest in self-organization processes increased. This paper will present a widely-used and versatile lattice Boltzmann model that can simultaneously incorporate fluid dynamics, heat transfer, buoyancy-driven convection, passive scalar advection, chemical reactions and enthalpy changes. All of these effects interact in a physically accurate framework that is simple to code and readily parallelizable. As well as a complete description of the model equations, several example systems will be presented in order to demonstrate the accuracy and versatility of the method. New simulations, which analyzed the effect of a reversible reaction on the transport properties of a convecting fluid, will also be described in detail. This extra chemical degree of freedom was utilized by the system to augment its net heat flux. The numerical method outlined in this paper can be readily deployed for a vast range of complex flow problems, spanning a variety of scientific disciplines.

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“…Recent studies on entropy generation analysis [27][28][29][30][31][32][33][34][35] reveal new methods for reducing computational cost and in which entropy generation due heat/mass transfer is analyzed. Chen et al [27] introduced a simple lattice Boltzmann model to investigate convectional phenomena at higher Rayleigh number up to 10 7 .They obtained that the flow is primarily dominated by thermal buoyancy effects, whereas for N > 1, the flow is mainly dominated by compositional buoyancy effects.…”

Section: Introductionmentioning

confidence: 99%

“…The variations of the total entropy generation number and Bejan number depend on the detailed combination of Reynolds and Grashof numbers. Entropy generation due to heat/mass transfer of turbulent natural convection due to internal heat generation in a cavity is studied by [31]. It was found that the time-volume averaged Bejan number almost equals one and then decreases quickly against Ra increasing.…”

Section: Introductionmentioning

confidence: 99%

Analysis of the Magnetic Field Effect on Entropy Generation at Thermosolutal Convection in a Square Cavity

Bouabid

Hidouri

Magherbi

et al. 2011

Entropy

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Thermosolutal convection in a square cavity filled with air and submitted to an inclined magnetic field is investigated numerically. The cavity is heated and cooled along the active walls with a mass gradient whereas the two other walls of the cavity are adiabatic and insulated. Entropy generation due to heat and mass transfer, fluid friction and magnetic effect has been determined in transient state for laminar flow by solving numerically the continuity, momentum energy and mass balance equations, using a Control Volume Finite-Element Method. The structure of the studied flows depends on four dimensionless parameters which are the Grashof number, the buoyancy ratio, the Hartman number and the inclination angle. The results show that the magnetic field parameter has a retarding effect on the flow in the cavity and this lead to a decrease of entropy generation, Temperature and concentration decrease with increasing value of the magnetic field parameter.

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Entropy generation in turbulent natural convection due to internal heat generation

Cited by 65 publications

References 42 publications

Multiple-relaxation-time lattice Boltzmann kinetic model for combustion

Multiple-relaxation-time lattice Boltzmann kinetic model for combustion

A Non-Isothermal Chemical Lattice Boltzmann Model Incorporating Thermal Reaction Kinetics and Enthalpy Changes

Analysis of the Magnetic Field Effect on Entropy Generation at Thermosolutal Convection in a Square Cavity

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