A Parabolic Temperature Profile Model for Heating of Droplets
01 Jun 2003-Journal of Heat Transfer-transactions of The Asme (American Society of Mechanical Engineers)-Vol. 125, Iss: 3, pp 535-537
TL;DR: In this article, a model for convective heating of droplets, which takes into account their finite thermal conductivity, is proposed, based on the assumption of the parabolic temperature profile in the droplets.
Abstract: A model for convective heating of droplets, which takes into account their finite thermal conductivity, is suggested. This model is based on the assumption of the parabolic temperature profile in the droplets. A rigorous numerical solution, without restrictions on temperature profiles inside droplets, is compared with predictions of the parabolic temperature profile and isothermal models
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TL;DR: In this article, the effect of finite thermal conductivity and recirculation in droplets can be taken into account using the so-called parabolic model, which is a reasonable compromise between accuracy and CPU efficiency.
724 citations
Cites background or methods from "A Parabolic Temperature Profile Mod..."
...(20)) gives [81]...
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...The parabolic temperature profile model was generalised to take into account the initial heating of droplets in [81], but the implementation of this generalised model into CFD codes has not yet been investigated....
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...(23) was called the parabolic temperature profile model [81]....
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...This allows us to approximate T(R) as [81]...
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...(24) and (28) gives [81]:...
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TL;DR: In this paper, a simplified model for bi-component droplet heating and evaporation is developed and applied for the analysis of the observed average droplet temperatures in a monodisperse spray.
163 citations
TL;DR: The results of comparative analysis of liquid and gas phase models for fuel droplets heating and evaporation, suitable for implementation into computational fluid dynamics (CFD) codes, are presented in this article.
147 citations
Cites background or methods from "A Parabolic Temperature Profile Mod..."
...Presentation (11) allows us to find the relation between Ts and T in the form [18]...
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...This model was called the parabolic temperature profile model [18]....
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...Following [18] we approximate this solution by the parabolic function...
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...A number of possible simplifications have been suggested [18,48]....
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...In [16–27] simplified models for droplet heating and evaporation have been developed....
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TL;DR: In this paper, the authors used a simplified model for thermal radiation absorption in a semi-transparent spherical droplet and applied it to the analysis of the vaporization process of n-decane and diesel fuel injected into hot air.
128 citations
TL;DR: In this article, the effect of temperature gradient inside fuel droplets on droplet evaporation, break-up and the ignition of fuel vapour/air mixture is investigated based on a zero-dimensional code.
117 citations
References
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TL;DR: In this article, isolated droplet vaporization, heating, and multi-component liquid droplets are discussed. But the authors focus on the behavior of droplet behavior at near critical, transcritical, and supercritical conditions.
Abstract: Preface 1. Introduction 2. Theory of isolated droplet vaporization, heating 3. Multicomponent liquid droplets 4. Droplet arrays and groups 5. Spray equations 6. Computational issues 7. Spray applications 8. Droplet interactions with turbulence and vortical structures 9. Droplet behavior at near critical, transcritical, and supercritical conditions Nomenclature References Appendices Index.
991 citations
TL;DR: In this paper, the applicability of radiation transfer theory for calculations of the thermal radiation emitted by spherical particle of a semitransparent material, and in particular the determination of radial heat generation profiles, is analyzed.
89 citations
TL;DR: In this article, the authors present some spray calculations in a combustion bomb and in a d.i. diesel engine for different test cases varying the formulation of the evaporation model in a modified version of the 3D-fluidynamic KIVA II code.
79 citations
TL;DR: In this article, a system of equations describing the effects of heating, evaporation, and combustion of fuel droplets in a monodisperse spray is simplified assuming that the Nusselt and Sherwood numbers are equal to 2.
76 citations
TL;DR: In this article, a method for the calculation of the temperature of large semitransparent particles of a material of low thermal conductivity during their motion in a gas jet is suggested.
Abstract: A method is suggested for the calculation of the temperature of large semitransparent particles of a material of low thermal conductivity during their motion in a gas jet. The temperature profile in a particle is calculated with due regard for thermal conductivity and thermal radiation. The results of calculations performed for typical parameters of a plasma jet demonstrate that the temperature at the center of an oxide particle 40–60 μm in diameter in the zone of heating may be 1500–2500 K lower than the temperature at the particle surface. Here, the error of prediction of the volume-average particle temperature in isothermal approximation reaches 350 K. The possibility of determining the volume-average temperature of particles by their thermal radiation is studied as applied to the problem of optical diagnostics of two-phase jets. It is demonstrated that the color temperature being measured may differ from the volume-average particle temperature by as much as 300 K. The possibility is discussed of experimentally determining the temperature dependence of the index of absorption, which would enable one to considerably increase the accuracy of the obtained values of the volume-average particle temperature.
6 citations