sustainability-logo

Journal Browser

Journal Browser

Special Issue "Influence of Biofuel Additions on the Ignition Delay of Single Diesel Fuel Drops"

A special issue of Sustainability (ISSN 2071-1050). This special issue belongs to the section "Sustainable Chemical Engineering and Technology".

Deadline for manuscript submissions: closed (30 June 2021).

Special Issue Editor

Dr. Laurencas Raslavičius
E-Mail Website
Guest Editor
Department of Transport Engineering, Kaunas University of Technology, 51424 Kaunas, Lithuania
Interests: microalgal biofuels for transport; energy and transport policy; interactions between scientific development, technological change, and private sector activities in the renewable energy sector

Special Issue Information

Dear Colleagues,

Until recently, it had not been recognized that diesel fuel blends with biofuels offer advantages for public transportation, hybrid or marine propulsion, agricultural and forestry machinery, industrial furnaces, boilers, etc. However, the nature of the fuel itself has a great influence on combustion-generated emissions. Accordingly, significant steps must be taken to control the components and the contaminants of fuel to minimize problems from emissions.

It is known that most conventional and alternative liquid fuels as well as their binary, ternary or multicomponent blends that are used for energetic means, especially these days, however, are mixtures of many chemical compounds with widely different volatilities. A detailed understanding of droplet ignition, droplet cluster ignition, and combustion are of interest in view of a detailed understanding of the ongoing basic physical and chemical processes. This kind of research is motivated by both (i) safety considerations in various systems, in which the ignition must be avoided (explosions in industrial installations, fire safety in space environments, and prevention of autoignition in the fuel delivery systems) and (ii) a pressing need for parametric studies to compile libraries of droplet ignition and combustion data as an essential prerequisite for any understanding of spray combustion and its application to the design of efficient combustion systems.

Combustion of a biofuel–diesel single droplets in an oxidizing atmosphere has been a subject of investigation over the past three decades after a few countries in Europe began to take an interest in biofuels in the early 1990s. While many reviews and original research articles have appeared on various aspects of droplet ignition, there are many important features which have yet to be explained. The present issue constitutes a reexamination of the problem of liquid biofuel–diesel droplet combustion and will therefore discuss experimental, theoretical, and computational research dealing with droplet ignition delay phenomena.

Examples of such cases include but are not limited to:

  • The droplet ignition in a high-pressure environment;
  • Ignition of bi-component and multicomponent droplets of oxygenated diesel fuel;
  • The effects of 1st–4th-generation biofuel additives on ignition delay of diesel fuel droplets;
  • The application of droplet theories with a special emphasis on ignition delay to the modeling of various combustion systems;
  • Determination of ignition characteristics of the droplets containing biological additives that are not yet commercialized and could potentially be produced from hundreds of different industrial and non-industrial species, like algal biomass;
  • Quasi-steady and unsteady models for the ignition of a fuel droplet in a stagnant environment;
  • Convective effects on droplet ignition.

Dr. Laurencas Raslavičius
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Sustainability is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1900 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • ignition delay
  • multicomponent effects
  • stationary droplets
  • freely-falling droplets
  • quasi-steady analysis
  • transient analysis
  • convective conditions
  • droplet cluster ignition
  • oxygenates
  • biocomponents

Published Papers (6 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Article
Comparison of Research Data of Diesel–Biodiesel–Isopropanol and Diesel–Rapeseed Oil–Isopropanol Fuel Blends Mixed at Different Proportions on a CI Engine
Sustainability 2021, 13(18), 10059; https://0-doi-org.brum.beds.ac.uk/10.3390/su131810059 - 08 Sep 2021
Viewed by 347
Abstract
Depletion in the levels of fossil fuels and increasing environmental concerns associated with the rise in consumption of conventional fuels are among the top global concerns. Finding an alternative sustainable fuel that matches the performance characteristics of diesel/petrol fuels as well as decreases [...] Read more.
Depletion in the levels of fossil fuels and increasing environmental concerns associated with the rise in consumption of conventional fuels are among the top global concerns. Finding an alternative sustainable fuel that matches the performance characteristics of diesel/petrol fuels as well as decreases the exhaust emissions has been a challenging task. After deliberate research, it is found that every alternative fuel is associated with different problems when they are used independently, thereby limiting its benefits. Scientists suggest that using different fuel blends might lead to sustainability. This article is the analysis of data obtained from the experimentation based on two different alternative fuels, Rapeseed Methyl Ester (RME)-based biodiesel and Rapeseed Oil (RO), blended with diesel (D) and Isopropanol (P) into three different proportions each. Tests were carried out in a compression ignition (CI) engine, and comparisons are based on the resulted performance and exhaust emission characteristics. The two different alternative fuels are blended into the following proportions to make six fuel mixtures, D50RME30P20, D50RME40P10, D50RME45P5, D50RO30P20, D50RO40P10 and D50RO45P5. The tests are carried out at different loads (BMEP) and are compared to that of pure diesel. Using the experimentation results, we also obtained the combustion characteristics of all fuel mixtures for further evaluation Full article
Show Figures

Figure 1

Article
Assessment of Microalgae Oil as a Carbon-Neutral Transport Fuel: Engine Performance, Energy Balance Changes, and Exhaust Gas Emissions
Sustainability 2021, 13(14), 7878; https://0-doi-org.brum.beds.ac.uk/10.3390/su13147878 - 14 Jul 2021
Cited by 1 | Viewed by 478
Abstract
Notwithstanding the substantial progress acheved since 2010 in the attempts to realize the potential of microalgae biofuels in the transportation sector, the prospects for commercial production of CO2-neutral biofuels are more challenging today than they were in 2010. Pure P. moriformis [...] Read more.
Notwithstanding the substantial progress acheved since 2010 in the attempts to realize the potential of microalgae biofuels in the transportation sector, the prospects for commercial production of CO2-neutral biofuels are more challenging today than they were in 2010. Pure P. moriformis microalgae oil was subjected to unmodified engine performance testing as a less investigated type of fuel. Conventional diesel was used as a reference fuel to compare and to contrast the energy balances of an engine as well as to juxtapose performance and emission indicators for both unary fuels. According to the methodology applied, the variation of BSFC rates, BTE, smoke opacity, NOx, HC, CO2, O2, and exhaust gas temperature on three different loads were established during compression ignition (CI) engine operation at EGR Off, 25% EGR, 18% EGR and 9% EGR modes, respectively. Simulation model (AVL Boost/BURN) was employed to assess the in-cylinder process parameters (pressure, pressure rise, temperature, temperature rise, ROHR, and MFB). Furthermore, the first law energy balances for an engine running on each of the test fuels were built up to provide useful insights about the peculiarities of energy conversion. Not depending on EGR mode applied, the CI engine running on microalgae oil was responsible for slightly higher BTE values, drastically reduced smoke opacity, higher CO2 values, and smaller O2 concentration, marginally increased NOx levels and lower total energy losses (in %) if compared to the performance with diesel fuel. Full article
Show Figures

Figure 1

Article
Prognostic Assessment of the Performance Parameters for the Industrial Diesel Engines Operated with Microalgae Oil
Sustainability 2021, 13(11), 6482; https://0-doi-org.brum.beds.ac.uk/10.3390/su13116482 - 07 Jun 2021
Cited by 1 | Viewed by 550
Abstract
A study conducted on the high-speed diesel engine (bore/stroke: 79.5/95.5 mm; 66 kW) running with microalgae oil (MAO100) and diesel fuel (D100) showed that, based on Wibe parameters (m and φz), the difference in numerical values of combustion characteristics was [...] Read more.
A study conducted on the high-speed diesel engine (bore/stroke: 79.5/95.5 mm; 66 kW) running with microalgae oil (MAO100) and diesel fuel (D100) showed that, based on Wibe parameters (m and φz), the difference in numerical values of combustion characteristics was ~10% and, in turn, resulted in close energy efficiency indicators (ηi) for both fuels and the possibility to enhance the NOx-smoke opacity trade-off. A comparative analysis by mathematical modeling of energy and traction characteristics for the universal multi-purpose diesel engine CAT 3512B HB-SC (1200 kW, 1800 min−1) confirmed the earlier assumption: at the regimes of external speed characteristics, the difference in Pme and ηi for MAO100 and D100 did not exceeded 0.7–2.0% and 2–4%, respectively. With the refinement and development of the interim concept, the model led to the prognostic evaluation of the suitability of MAO100 as fuel for the FPT Industrial Cursor 13 engine (353 kW, 6-cylinders, common-rail) family. For the selected value of the indicated efficiency ηi = 0.48–0.49, two different combinations of φz and m parameters (φz = 60–70 degCA, m = 0.5 and φz = 60 degCA, m = 1) may be practically realized to achieve the desirable level of maximum combustion pressure Pmax = 130–150 bar (at α~2.0). When switching from diesel to MAO100, it is expected that the ηi will drop by 2–3%, however, an existing reserve in Pmax that comprises 5–7% will open up room for further optimization of energy efficiency and emission indicators. Full article
Show Figures

Figure 1

Article
The Influence of Droplet Dispersity on Droplet Vaporization in the High-Temperature Wet Gas Flow in the Case of Combined Heating
Sustainability 2021, 13(7), 3833; https://0-doi-org.brum.beds.ac.uk/10.3390/su13073833 - 31 Mar 2021
Viewed by 404
Abstract
The change in the thermal and energy state of the water droplet is defined numerically. The influence of droplet dispersity on the interaction of the transfer processes was evaluated. In influence of the Stefan flow was considered as well. The internal heat transfer [...] Read more.
The change in the thermal and energy state of the water droplet is defined numerically. The influence of droplet dispersity on the interaction of the transfer processes was evaluated. In influence of the Stefan flow was considered as well. The internal heat transfer of the droplet was defined by the combined heat transfer through effective conductivity and radiation model. The results of the numerical modeling of heat and mass transfer in water droplets in a wet flue gas flow of 1000 °C highlight the influence of the variation in heat transfer regimes in the droplet on the interaction of the transfer processes in consistently varying phase change regimes. The results of the investigation shows that the inner heat convection diminishes intensively in the transitional phase change regime because of a rapid slowdown of the slipping droplet in the gas. The radiation absorption in the droplet clearly decreases only at the final stage of equilibrium evaporation. The highlighted regularities of the interaction between combined transfer processes in water droplets are also valid for liquid fuel and other semi-transparent liquids sprayed into high-temperature flue gas flow. However, a qualitative evaluation should consider individual influence of dispersity that different liquids have. Full article
Show Figures

Figure 1

Article
An Improved Prediction of Pre-Combustion Processes, Using the Discrete Multicomponent Model
Sustainability 2021, 13(5), 2937; https://0-doi-org.brum.beds.ac.uk/10.3390/su13052937 - 08 Mar 2021
Cited by 2 | Viewed by 695
Abstract
An improved heating and evaporation model of fuel droplets is implemented into the commercial Computational Fluid Dynamics (CFD) software CONVERGE for the simulation of sprays. The analytical solutions to the heat conduction and species diffusion equations in the liquid phase for each time [...] Read more.
An improved heating and evaporation model of fuel droplets is implemented into the commercial Computational Fluid Dynamics (CFD) software CONVERGE for the simulation of sprays. The analytical solutions to the heat conduction and species diffusion equations in the liquid phase for each time step are coded via user-defined functions (UDF) into the software. The customized version of CONVERGE is validated against measurements for a single droplet of n-heptane and n-decane mixture. It is shown that the new heating and evaporation model better agrees with the experimental data than those predicted by the built-in heating and evaporation model, which does not consider the effects of temperature gradient and assumes infinitely fast species diffusion inside droplets. The simulation of a hollow-cone spray of primary reference fuel (PRF65) is performed and validated against experimental data taken from the literature. Finally, the newly implemented model is tested by running full-cycle engine simulations, representing partially premixed compression ignition (PPCI) using PRF65 as the fuel. These simulations are successfully performed for two start of injection timings, 20 and 25 crank angle (CA) before top-dead-centre (BTDC). The results show good agreement with experimental data where the effect of heating and evaporation of droplets on combustion phasing is investigated. The results highlight the importance of the accurate modelling of physical processes during droplet heating and evaporation for the prediction of the PPCI engine performance. Full article
Show Figures

Figure 1

Article
Parametric Analysis of the Combustion Cycle of a Diesel Engine for Operation on Natural Gas
Sustainability 2021, 13(5), 2773; https://0-doi-org.brum.beds.ac.uk/10.3390/su13052773 - 04 Mar 2021
Cited by 2 | Viewed by 461
Abstract
The publication research task is related to one of the solution aspects in reference to decarbonization of transport by transferring the operation of diesel engines to natural gas. The results of converted diesel engines into operation with dual-fuel (D-NG) without significant constructive modifications [...] Read more.
The publication research task is related to one of the solution aspects in reference to decarbonization of transport by transferring the operation of diesel engines to natural gas. The results of converted diesel engines into operation with dual-fuel (D-NG) without significant constructive modifications are focused on forecasting the energy efficiency parameters of in-service engine models and evaluation of the reserves improvement. This paper presents energy efficiency parameters and characteristics of the combustion cycle methodological optimization of high-speed 79.5/95.5 mm diesel engine with a conventional fuel injection system. Interrelations between the indicated efficiency (ηi), combustion cycle performance parameters (excess air ratio (α), compression ratio (ε), degree of pressure increase in the cylinder (λ), maximum cycle pressure (pmax), air pressure (pk), air temperature (Tk) after compression, etc.), and heat release characteristics were determined and researched. Directions of the optimization when the engines were operating in a wide range of load (pmi) modes were also obtained: the low energy efficiency in the low-load mode were due to reduced heat release dynamics (combustion time increased up to 200° CA). The main influencing factors for ηi were the pilot-injection portion phase (φinj) and α, optimization of ε was inefficient. To avoid exceeding the permissible limits of reliability for pmax, the realized reserve of ηi increase was estimated as 10%. Methodological tools for the practical application of parametric analysis to the conversion of diesel to dual-fuel operation have been developed and adapted in the form of a numerical modeling algorithm, which was presented in nomogram form. For improvement of initial energy parameters for a specific engine models heat release characteristics identification, accurate methods must be used. The proposed methodology is seen as a theoretical tool for a dual-fuel conversion models for in-service engines and has benefit of a practical use of a fast application in the industrial field. Full article
Show Figures

Figure 1

Back to TopTop