A Comprehensive Numerical Study of Diesel Fuel Spray Formation with OpenFOAM

Kösters, Anne

doi:10.4271/2011-01-0842

Cited by 10 publications

(3 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…where j true→ is the heat flux vector, and q · ev is the enthalpy defect due to the evaporation of liquid fuel, which is determined by the spray model. 23 Viscous heating has been neglected, what is an reasonable assumption for low-Mach-number flow.…”

Section: Computational Modelsmentioning

confidence: 99%

Investigation of turbulence–chemistry interactions in a heavy-duty diesel engine with a representative interactive linear eddy model

Lackmann

Nygren

Oevermann

2018

International Journal of Engine Research

Self Cite

View full text Add to dashboard Cite

Simulations of a heavy-duty diesel engine operated at high-load and low-load conditions were compared to each other, and experimental data in order to evaluate the influence of turbulence–chemistry interactions on heat release, pressure development, flame structure, and temperature development are quantified. A recently developed new combustion model for turbulent diffusion flames called representative interactive linear eddy model which features turbulence–chemistry interaction was compared to a well-stirred reactor model which neglects the influence of turbulent fluctuations on the mean reaction rate. All other aspects regarding the spray combustion simulation like spray break-up, chemical mechanism, and boundary conditions within the combustion chamber were kept the same in both simulations. In this article, representative interactive linear eddy model is extended with a progress variable, which enables the model to account for a flame lift-off and split injection, when it is used for diffusion combustion. In addition, the extended version of representative interactive linear eddy model offers the potential to treat partially premixed and premixed combustion as well. The well-stirred reactor model was tuned to match the experimental results, thus computed pressure and apparent heat release are in close agreement with the experimental data. Representative interactive linear eddy model was not tuned specifically for the case and thus the computed results for pressure and heat release are in reasonable agreement with experimental data. The computational results show that the interaction of the turbulent flow field and the chemistry reduce the peak temperatures and broaden up the turbulent flame structure. Since this is the first study of a real combustion engine (metal engine) with the newly developed model, representative interactive linear eddy model appears as a promising candidate for predictions of spray combustion in engines, especially in combustion regimes where turbulence–chemistry interaction plays an even more important role like, example given, in low-temperature combustion or combustion with local extinction and re-ignition.

show abstract

Section: Computational Modelsmentioning

confidence: 99%

Investigation of turbulence–chemistry interactions in a heavy-duty diesel engine with a representative interactive linear eddy model

Lackmann

Nygren

Oevermann

2018

International Journal of Engine Research

Self Cite

View full text Add to dashboard Cite

show abstract

“…The idea to consider a sphere around every parcel is not completely new. Kösters and Karlsson (2011) applied it in the implementation of the Stochastic Blob and Bubble spray model, also known as VSB2 model. In that approach the idea was to construct a model that treats the spray and its break-up as one process, instead of summing individual, fragmenting droplets to a spray.…”

Section: The Vsb2 Model As a Starting Pointmentioning

confidence: 99%

A Spherical Volume Interaction DDM Approach for Diesel Spray Modeling

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Such thermodynamic equilibrium condition is then used to compute the evaporation rate as will be explained in detail in the next section. Such implicit approaches are normally based on the assumption that locally the liquid is completely evaporated at equilibrium state [13]. This is not generally true, since for non diluted cases some amount of liquid remains even at equilibrium state.…”

Section: Introductionmentioning

confidence: 99%

Development of an evaporation model for the dense spray region in Eulerian-Eulerian multiphase flow simulations

Puggelli¹,

Palanti²,

Andreini³

et al. 2017

Proceedings ILASS–Europe 2017. 28th Conference on Liquid Atomization and Spray Systems

View full text Add to dashboard Cite

In the present study, a novel implicit numerical model to describe evaporation phenomena in the dense spray region is proposed. The main aim is to go beyond the limits of standard vaporization models, which are normally based on a dilute spray assumption, to deal with high liquid volume fractions. The proposed method is based on an a priori computation of steady state equilibrium conditions reached by a system composed by liquid, vapour and air at constant pressure combined with a modelled characteristic time of evaporation. Such equilibrium composition and temperature is then used inside numerical calculations to compute evaporation source terms. The new formulation allows to simulate evaporation process in the dense zone of the spray, where, due to the extremely low thermal relaxation time, classical explicit method can lead to unphysical results. Such innovative approach has been implemented in a multiphase solver in the framework of the CFD suite OpenFOAM. An Eulerian-Eulerian solver, derived from the Eulerian Lagrangian Spray Atomization (ELSA) model, has been used, in order to correctly describe the liquid-gas flow without assumptions on the topology of the liquid phase. Evaporation source terms have been modelled as function of the amount of surface available for mass and heat transfer. An analysis of the solver has been carried out in RANS framework in order to highlight the capabilities of the approach in dealing with high liquid volume fraction regions with a physically consistent representation of evaporation phenomena. KeywordsSpray modelling, ELSA, Eulerian-Eulerian methods, Evaporation modelling. IntroductionThe future standards on pollutants emissions expected by ICAO-CAEP [1] for the next generation of civil aeroengines have pushed the attention towards the introduction of lean burn technology in aeronautical framework. Here, a drastic reduction of NOx levels can be achieved working on a narrow range of temperature and equivalence ratio. Therefore, all the issues related to liquid fuel atomization and air-fuel mixing have to be carefully investigated and Computational Fluid Dynamics (CFD) has been gaining strong attention for the design process. In this framework, the numerical method chosen for the modelling of the liquid phase can have a strong impact on both simulation accuracy and computational effort. Standard Eulerian-Lagrangian (E-L) approaches, which are based on tracking single liquid discrete entities (i.e. parcels), are characterized by a straightforward introduction of the main interactions between the gas and the liquid phase, even if they are not theoretically suitable in the near injection region where the spray is really dense. An extensive use of experimental correlations in order to introduce the effects of primary breakup inside numerical calculations is therefore required. However, this strategy is not general since a strong spreading between the huge number of available experimental correlations can be determined for the same configuration and operating conditions. Be...

show abstract

A Comprehensive Numerical Study of Diesel Fuel Spray Formation with OpenFOAM

Cited by 10 publications

References 16 publications

Investigation of turbulence–chemistry interactions in a heavy-duty diesel engine with a representative interactive linear eddy model

Investigation of turbulence–chemistry interactions in a heavy-duty diesel engine with a representative interactive linear eddy model

A Spherical Volume Interaction DDM Approach for Diesel Spray Modeling

Development of an evaporation model for the dense spray region in Eulerian-Eulerian multiphase flow simulations

Contact Info

Product

Resources

About