Numerical study on flash‐boiling spray of multicomponent fuel

Kawano, Daisuke; Ishii, Hajime; Suzuki, Hisakazu; Goto, Yuichi; Odaka, Matsuo; Senda, Jiro

doi:10.1002/htj.20117

Cited by 37 publications

(4 citation statements)

References 23 publications

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“…The growth of a single bubble was firstly described by Rayleigh [3] and Plesset [4]. Examples of incorporating the Rayleigh-Plesset model in CFD methods for calculating bubble growth and collapse can be found in Kawano et al [5] and Giannadakis et al [6]. Some studies assumed thermodynamic equilibrium using the homogeneous equilibrium model (HEM).…”

Section: Introductionmentioning

confidence: 99%

Numerical simulation of flash-boiling through sharp-edged orifices

Lyras¹,

Dembele²,

Vyazmina³

et al. 2017

Int. J. CMEM

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Flash boiling is the rapid phase change of a pressurised fluid that emerges to ambient conditions below its vapour pressure. Flashing of a flowing liquid through an orifice or a nozzle can occur either inside or outside the nozzle depending on the local pressure and geometry. Vapour generation during flashing leads to interfacial interactions that eventually influence the jet.Empirical models in the literature for simulating the inter-phase heat transfer employ many simplifying assumptions, which limits their applicability. Typical models, usually derived from cavitation, fail to describe the physics of heat and mass transfer, making them unreliable for flashing. The Homogeneous Relaxation Model (HRM) is a reliable model able to capture heat transfer under these conditions accounting for the non-equilibrium vapour generation. This approach uses a relaxation term in the transport equation for the vapour. On the basis of the generic compressible flow solver within the open source computational fluid dynamics (CFD) code OpenFOAM, the HRM has been implemented to create a dedicated new solver HRMSonicELSAFoam. An algorithm that links the standard pressure-velocity coupling algorithm to the HRM is used. In this method, a pressure equation is derived which employs the continuity equation including compressibility effects. A relaxation term has been defined such that the instantaneous quality would relax to the equilibrium value over a given timescale. Although it is possible to consider this timescale constant, it is calculated via an empirical correlation in the present study.Validations have been carried out by simulating two-phase flows through sharp-edged orifices. The relatively good agreement achieved has demonstrated that the solver accurately calculates the pressure and vapour mass fraction. This demonstrates the potential of HRMSonicELSAFoam for flash boiling simulations and predicting the properties of the subsequent flash atomisation.

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Section: Introductionmentioning

confidence: 99%

Numerical simulation of flash-boiling through sharp-edged orifices

Lyras¹,

Dembele²,

Vyazmina³

et al. 2017

Int. J. CMEM

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“…where μc is in micropoise (1 uP=10 −7 Pa s). The parameter R' is defined as followed The coefficient e0 is a function of molecular mass Mw and acentric factor ω: (42) The above viscosity model developed from PR EOS has been used by many authors [14] [26] with good results. Equation (33) can also be expressed in terms of compressibility factor by using, in analogy with PR-EOS, a generalized equation for viscosity of the kind (43) In this case, by settings (44) and it can be solved by the same numerical algorithm implemented in the PR cubic eos.…”

Section: Viscositymentioning

confidence: 99%

“…Application to Modern Internal Combustion EnginesCubic EOS are normally not implemented in open source CFD codes and sometimes they are present in commercial codes, but not as a default thermodynamic solver; historically, their use has been restricted to specialized VLE calculations. The use of multi-component real like fuels brought the interest for cubic EOS among the internal combustion engine community; Kawano et al[42] implemented a PR-EOS in KIVA 3v to simulate liquid-vapour equilibrium in numerical simulation of flash boiling sprays of multi-component fuels; Neroorkar and Schmidt[43] implemented a PR-EOS in Open FOAM to calculate saturated liquid densities of gasoline-ethanol blends in direct injection engines, Negro and Bianchi[4] used a VTPR-EOS in a homogeneous one-dimensional model for predicting nozzle chocking in superheated liquid fuel injectors, the recent works of Qiu and Reitz[44] [10] report of an implementation of a PR-EOS in KIVA 3v to account for real gas effects and phase change in supercritical injections and fuel condensation, Ma et al[45] adopted a PR-EOS to account for the consistent thermodynamics in supercritical and transcritical regimes, simulating transcritical ndodecane injections in a Diesel engine. This brief literature review is certainly not comprehensive, but it gives an idea of the growing interest towards the PR-EOS in engine simulations.…”

mentioning

confidence: 99%

Coefficients for the calculation of thermophysical properties of indolene/ethanol biofuels for transcritical engine simulations

Negro

Falfari

Bianchi

2016

Combustion and Flame

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“…It is widely accepted that bubble nucleation provides the initiating mechanism for flash boiling. The specifics depend on how the bubbles form, whether from surface imperfections (e.g., within the atomizer, on solid impurities in the liquid, or on combustor walls when droplets impinge on them) or homogeneously within the bulk of the liquid. ,,− There is renewed interest in the process as it relates to fuel efficiency in combustion engines. , …”

Section: Introductionmentioning

confidence: 99%

Initiation of Flash Boiling of Multicomponent Miscible Mixtures with Application to Transportation Fuels and Their Surrogates

et al. 2018

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This paper presents methodologies to predict thermodynamic conditions that initiate flash boiling by spontaneous nucleation of liquids consisting of hundreds of miscible liquids and their lower order surrogate mixtures. The methods are illustrated with a kerosene-based fuel and a seven-component surrogate for it. The predictions are compared to measurements of nucleation temperatures obtained from a pulse-heating technique that rapidly heats a microscale platinum film immersed in a pool of the test fluid. Nucleation temperatures are predicted using a generalized corresponding states principle (GCSP), and a modification of classical nucleation theory that considers the mixture as a pseudo single component fluid (PSCF). The intent is to offer a simple means to predict the initiation of flash boiling that can have important consequences for fuel efficiency in combustion engines. We show that contact angle has a strong effect such that predicted and measured spontaneous nucleation temperatures agree for a given heating rate only if contact angle is accounted for in the theory. For low heating rates (less than 2 × 107 K/s), predicted nucleation temperatures, assuming a spherical bubble, are 13% higher than measurements. The gap is closed to about 6% as the heating rate reaches 3 × 108 K/s (the highest that could be reached in the experiments) and to less than 1% when the measured nucleation temperature is extrapolated to an asymptotic (zero contact angle) limit. The PSCF method (using mixture properties as mole fraction averages of mixture component properties evaluated at the same reduced temperatures as the mixtures) and the GSCP predict virtually identical nucleation temperatures, while the GCSP method does not require any mixture property values.

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Numerical study on flash‐boiling spray of multicomponent fuel

Cited by 37 publications

References 23 publications

Numerical simulation of flash-boiling through sharp-edged orifices

Numerical simulation of flash-boiling through sharp-edged orifices

Coefficients for the calculation of thermophysical properties of indolene/ethanol biofuels for transcritical engine simulations

Initiation of Flash Boiling of Multicomponent Miscible Mixtures with Application to Transportation Fuels and Their Surrogates

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