Convective vaporization of a fuel droplet with thermal radiation absorption

a b s t r a c tThe results of numerical and experimental studies of heating and evaporation of monodisperse acetone, ethanol, 3-pentanone, n-heptane, n-decane and n-dodecane droplets in an ambient air of fixed temperature and atmospheric pressure are reported. The numerical model took into account the finite thermal conductivity of droplets and recirculation inside them based on the effective thermal conductivity model and the analytical solution to the heat conduction equation inside droplets. The effects of interaction between droplets are taken into account based on the experimentally determined corrections to Nusselt and Sherwood numbers. It is pointed out that the interactions between droplets lead to noticeable reduction of their heating in the case of ethanol, 3-pentanone, n-heptane, n-decane and n-dodecane droplets, and reduction of their cooling in the case of acetone. Although the trends of experimentally observed droplet temperatures and radii are the same as predicted by the model taking into account the interaction between droplets, the actual values of the predicted droplet temperatures can differ from the observed ones by up to about 8 K, and the actual values of the predicted droplet radii can differ from the observed ones by up to about 2%. It is concluded that the effective thermal conductivity model, based on the analytical solution to the heat conduction equation inside droplets, can predict the observed average temperature of droplets with possible errors not exceeding several K, and observed droplet radii with possible errors not exceeding 2% in most cases. These results allow us to recommend the implementation of this model into CFD codes and to use it for multidimensional modelling of spray heating and evaporation based on these codes.

show abstract

“…For the binary diffusion coefficient of n-decane (C 10 H 22 ) we used the following approximation [24]: …”

Section: Discussionmentioning

confidence: 99%

“…Other physical properties of n-heptane and ndodecane were assumed to be the same as in [12] (most of these properties were approximated using data from [22,23]). The physical properties of n-decane were taken to be the same as in [24], while the properties of acetone, ethanol and 3-pentanone were taken from [17,22,25]. …”

Section: Methodsmentioning

confidence: 99%

Monodisperse monocomponent fuel droplet heating and evaporation

Kristyadi

Deprédurand

Castanet

et al. 2010

Fuel

View full text Add to dashboard Cite

show abstract

“…It is assumed that these values do not depend on the composition of this mixture and can be assumed equal to D v = 2 × 10 −10 T 1.75 . In the general case when p is not equal to 1 bar, this expression should be generalised to [44,51]:…”

Section: Vapour Diffusion Coefficientsmentioning

confidence: 99%

Modelling of biodiesel fuel droplet heating and evaporation

Sazhin

Qubeissi

Kolodnytska

et al. 2014

Fuel

112

View full text Add to dashboard Cite

Biodiesel fuel droplet heating and evaporation is investigated using the previously developed models, taking into account temperature gradient, recirculation, and species diffusion within droplets. The analysis is focused on four types of biodiesel fuels: Palm Methyl Ester, Hemp Methyl Esters, Rapeseed oil Methyl Ester, and Soybean oil Methyl Ester. These fuels contain up to 15 various methyl esters and possibly small amounts of unspecified additives, which are treated as methyl esters with some average characteristics. Calculations are performed using two approaches: 1) taking into account the contribution of all components of biodiesel fuels (up to 16); and 2) assuming that these fuels can be treated as a one component fuel with averaged transport and thermodynamic coefficients. It is pointed out that for all types of biodiesel fuel the predictions of the multi-component and single component models are rather close (the droplet evaporation times predicted by these models differ by less than about 5.5%). This difference is much smaller than observed in the case of Diesel and gasoline fuel droplets, and is related to the 1 Corresponding author, e-mail: S.Sazhin@brighton.ac.uk Preprint submitted to FuelMarch 28, 2013 fact that in the case of Diesel and gasoline fuel droplets the contribution of components in a wide range of molar masses and enthalpies of evaporation needs to be taken into account, while in the case of biodiesel fuels the main contribution comes from the components in a narrow range of molar masses and enthalpies of evaporation. As in the case of Diesel and gasoline fuel droplets, the multi-component model predicts higher droplet surface temperature and longer evaporation times than the single component model.

show abstract

“…The full compositions of diesel and biodiesel fuels were considered. The diesel fuel consisted of 98 hydrocarbons and the 19 biodiesel fuels, TME, LME, BME, CME, PMK, PME, SFE, PTE, CSE, CNE, SNE, SME, RME, LNE, TGE, HME1, HME2, CAN and WCO, consisted of 11,8,14,8,11,10,4,8,7,8,7,7,8,6,7,13,7, 12 and 14 components of methyl esters, respectively. The effect of increasing biodiesel fuel concentration on the evolutions of droplet surface temperature and evaporation time was clearly illustrated.…”

Section: Resultsmentioning

confidence: 99%

Droplets heating and evaporation: an application to diesel-biodiesel fuel mixtures

Qubeissi

Al-Esawi

Sazhin

2017

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

View full text Add to dashboard Cite

The heating and evaporation of automotive fuel droplets are crucial to the design of internal combustion engines and to ensuring their good performance. Accurate modelling is essential to the understanding of these processes and ultimately improving engine design. The interest in fossil-biodiesel fuel blends has been mainly stimulated by depletion of fossil fuels and the need to reduce carbon dioxide emissions that contribute towards climate change. This paper presents an analytical investigation into the application of discrete component model for the heating and evaporation of multi-component fuel droplets to several blended diesel-biodiesel fuels. The model considers the contribution of all groups of hydrocarbons in diesel fuel and methyl esters in biodiesel fuels. The main features of new application to the analysis of blended-fuel droplets in engine-like conditions is described. The model is applied to several blends of diesel, combining 98 components of hydrocarbons, and 19 types biodiesel fuels, combining up to 17 species of methyl ester, considering the differences in their chemical levels of saturation, and thermodynamic and transport properties. One important finding is that some fuel blends, e.g. B5 (5% biodiesel fuel and 95% diesel fuel), can give almost identical droplet lifetimes to the one predicted for pure diesel fuel; i.e. such mixtures can be directly used in conventional diesel engines with minimal, or no, modification to the droplet break-up process. KeywordsBiodiesel, Diesel, Fuel droplet, Fuel mixture, Heating and evaporation IntroductionRenewable sources of energy, such as biodiesel fuels, have been of great interest to scientists and public in the last decades due to depletion of fossil fuels and impact on global warming [1,2]. Also, compared to fossil fuel, biodiesel fuel has several advantages: it has less carbon dioxide emissions, higher flash point, higher lubricity and it is cost effective; in addition, the blend of diesel-biodiesel fuels can be used in diesel engines with minimal/no modifications [3,4]. The delay in processes preceding the onset of combustion (mainly the heating and evaporation of fuel droplets) in the internal combustion engines is crucial to the design and performance of these engines [5,6]. However, the complexity of modelling these processes should be taken into account as it involves detailed physics of heat transfer, mass transfer and fluid dynamics associated processes. In this paper, the discrete component model (DCM) (see [5][6][7]) is utilised to analyse the droplets heating and evaporation of diesel-biodiesel fuel blends. These blends are represented by a mixture of 19 types of biodiesel fuels with up to 17 species of methyl ester (see [8] for more details) and diesel fuel, formed of 98 hydrocarbons (see [7] for more details). The thermodynamic and transport properties of diesel fuel are inferred from [7]; while for properties of biodiesel fuel are taken from [9]. The contribution of species and average droplet temperatures are taken into account...

show abstract

Convective vaporization of a fuel droplet with thermal radiation absorption

Cited by 127 publications

References 32 publications

Monodisperse monocomponent fuel droplet heating and evaporation

Monodisperse monocomponent fuel droplet heating and evaporation

Modelling of biodiesel fuel droplet heating and evaporation

Droplets heating and evaporation: an application to diesel-biodiesel fuel mixtures

Contact Info

Product

Resources

About