scholarly journals Assessment of the impact of nanosecond plasma discharge on the combustion of methane air flames

2020 ◽  
Vol 197 ◽  
pp. 10001
Author(s):  
Donato Fontanarosa ◽  
Ghazanfar Mehdi ◽  
Maria Grazia De Giorgi ◽  
Antonio Ficarella

At present, development of plasma assisted ignition and combustion is a very promising research area due to its wide applications in the field of aeronautical engines and power sector. Plasma discharge can improve the combustion because it produces large number of chemically active particles which affects the chemical reaction. Simulation is an effective tool to analyze the interaction between the plasma and the flame through the implementation of plasma-assisted combustion. This study focused on three main objectives. Initially a microscopic plasma model with detailed kinetic plasma mechanisms was developed, then the validation of these mechanisms in air/methane mixture has been performed. Finally, the effects of nano pulsed plasma discharge on combustion have been investigated. In order to accomplish the above task, two numerical tools Chemical Kinetic Solver (CHEMKIN) and Plasma Kinetic Solver (ZDPlasKin) are used. It was found that the kinetic model of plasma provides good overall agreement with experimental data and identify key processes for species (e.g. O atom) generation and decay. The results showed that with the increase of reduced electric field, active particles and intermediate species/radicals (in particular ozone) are increased. ZDPlasKin results were incorporated in CHEMKIN to investigate and compare the flame speed, thermal and chemical effect by using a GRI-Mech scheme modified with the addition of ozone reactions. It has been found that with the adding of plasma flame speed was increased up to 26% at stoichiometric ratio. The chemical heat release also showed increment at low temperatures that confirmed the combustion enhancement. Furthermore, ignition delay timings were significantly reduced with the plasma excitation.

2021 ◽  
Author(s):  
Ghazanfar Mehdi ◽  
Maria Grazia De Giorgi ◽  
Donato Fontanarosa ◽  
Sara Bonuso ◽  
Antonio Ficarella

Abstract This study focused on the comparative analysis about the production of ozone and active radicals in presence of nanopulsed plasma discharge on air and on fuel/air mixture to investigate its effect on combustion enhancement. This analysis is based on numerical modeling of air and methane/air plasma discharge with different repetition rates (100 Hz, 1000 Hz and 10000 Hz). To this purpose, a two-step approach has been proposed based on two different chemistry solvers: a 0-D plasma chemistry solver (ZDPlasKin toolbox) and a combustion chemistry solver (CHEMKIN software suite). Consequently, a comprehensive chemical kinetic scheme was generated including both plasma excitation reactions and gas phase reactions. Validation of air and methane/air mechanisms was performed with experimental data. Kinetic models of both air and methane/air provides good fitting with experimental data of O atom generation and decay process. ZDPlasKin results were introduced in CHEMKIN in order to analyze combustion enhancement. It was found that the concentrations of O3 and O atom in air are higher than the methane/air activation. However, during the air activation peak concentration of ozone was significantly increased with repetition rates and maximum was observed at 10000 Hz. Furthermore, ignition timings and flammability limits were also improved with air and methane/air activation but the impact of methane/air activation was comparatively higher.


Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6463
Author(s):  
Xiaoyang Guo ◽  
Erjiang Hu ◽  
Xiaotian Li ◽  
Geyuan Yin ◽  
Zuohua Huang

A study on forced ignition characteristics of RP-3 jet fuel-air mixture was conducted around a constant volume combustion vessel and a nanosecond pulsed plasma discharge power supply. Experiments were carried out at different initial pressures (pu = 0.2, 0.3, 0.5 atm), equivalence ratios (ϕ = 0.7, 0.8, 1.1), steam concentrations (ZH2O = 0%, 10%, 15%) and oxygen concentrations (ZO2 = 13.5%, 16%, 21%). The relationship between ignition probability and ignition energy is investigated. The experimental results show that the decrease in pressure, equivalence ratio, oxygen concentration and the increase in steam concentration all lead to an increase in minimum ignition energy (MIE). In order to further analyze the experimental data, one existing fitting equation is reformed with the initial conditions taken into account. Multivariate fitting is carried out for different conditions, and the fitting results of ignition probability are in good agreement with the experiments. The MIE results under different experimental conditions are figured out with the new fitting equation. The impact indexes, which stand for the effects of different factors, are also calculated and compared in present work.


2020 ◽  
Vol 91 (3) ◽  
pp. 31301
Author(s):  
Nabil Chakhchaoui ◽  
Rida Farhan ◽  
Meriem Boutaldat ◽  
Marwane Rouway ◽  
Adil Eddiai ◽  
...  

Novel textiles have received a lot of attention from researchers in the last decade due to some of their unique features. The introduction of intelligent materials into textile structures offers an opportunity to develop multifunctional textiles, such as sensing, reacting, conducting electricity and performing energy conversion operations. In this research work nanocomposite-based highly piezoelectric and electroactive β-phase new textile has been developed using the pad-dry-cure method. The deposition of poly (vinylidene fluoride) (PVDF) − carbon nanofillers (CNF) − tetraethyl orthosilicate (TEOS), Si(OCH2CH3)4 was acquired on a treated textile substrate using coating technique followed by evaporation to transform the passive (non-functional) textile into a dynamic textile with an enhanced piezoelectric β-phase. The aim of the study is the investigation of the impact the coating of textile via piezoelectric nanocomposites based PVDF-CNF (by optimizing piezoelectric crystalline phase). The chemical composition of CT/PVDF-CNC-TEOS textile was detected by qualitative elemental analysis (SEM/EDX). The added of 0.5% of CNF during the process provides material textiles with a piezoelectric β-phase of up to 50% has been measured by FTIR experiments. These results indicated that CNF has high efficiency in transforming the phase α introduced in the unloaded PVDF, to the β-phase in the case of nanocomposites. Consequently, this fabricated new textile exhibits glorious piezoelectric β-phase even with relatively low coating content of PVDF-CNF-TEOS. The study demonstrates that the pad-dry-cure method can potentially be used for the development of piezoelectric nanocomposite-coated wearable new textiles for sensors and energy harvesting applications. We believe that our study may inspire the research area for future advanced applications.


2016 ◽  
Vol 1 (90) ◽  
pp. 92-97
Author(s):  
I.T. Slusar ◽  
V.A. Serbenyuk ◽  
A.N. Gera ◽  
A.P. Solyanik ◽  
A.A. Tarasenko

Research on the impact of the introduction of micro fertilizers and growth promoters on a background of mineral fertilizer and without N90R45К120 spent on old peat in shallow carbonate floodplain r.Supiy, Yahotyn Kyiv region. Power peat horizon about 60-70 cm, 7,4-7,6 pH of the aqueous extract, stupas schedule 56-60%, density 0,49-0,52 assembly soil, total nitrogen content (%) - 1.9; gross forms of phosphorus - 0,4, potassium 0.2, 20% lime. In experiments studying biological rehoplant, radustym, Biolan, emistim, Jets, humisol, plantafol, radyfarm and micronutrients: copper, boric acid, manganese sulphate, zinc sulphate, potassium humates. Treatment drugs conducted in the spring by spraying mixtures. Space research area of 60 m2, three-time repetition. It is established that the use of growth stimulants and micronutrients in the background N90R45К120 provided the highest yield mixtures of years, against making BIOLan - 9.9 t / ha Radyfarmu - 9.6 t / ha Radostymu 9.3 t / ha dry weight. In areas for making other preparations were intermediate yield growth rates - 0.5 - 2.0 t / ha dry weight. Also good gains herbage yields obtained by making all kinds of micronutrients and growth stimulants in the background without making makrodobryv which was within 5.3 - 6.9 t / ha to control without fertilization - 4.5 t / ha dry weight. In deep peat copper fertilizer (25 kg / ha of copper sulphate or 5 kg / ha pirytnoho cinders) in all zones should be making every 3-4 years, and zinc, cobalt and molybdenum advisable to make time for the growing season, spring, by foliar application in such numbers: ammonium molibdenovokyslyy - 0.3 kg / ha; cobalt sulfate - 3 kg / ha zinc sulphate 0.5 kg / ha or placers these salts should be mixed with major fertilizer.


Author(s):  
Maryam Karami ◽  
Mojgan Ghanbari ◽  
Hassan Abbas Alshamsi ◽  
Somaye Rashki ◽  
Masoud Salavati-Niasari

In the present study, Tl4HgI6 nanostructures have been successfully fabricated through a simple precipitation route. The impact of TlI stoichiometric ratio to HgI2, and kind of surfactants was explored on...


Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Jure Žigon ◽  
Matjaž Pavlič ◽  
Pierre Kibleur ◽  
Jan Van den Bulcke ◽  
Marko Petrič ◽  
...  

AbstractPlasma treatment is becoming a mature technique for modification of surfaces of various materials, including wood. A better insight in the treatment process and the impact of the plasma on properties of wood bulk are still needed. The study was performed on Norway spruce and common beech wood, as well as their thermally modified variations. The formations of the airborne discharge, as well as mass changes of the treated wood, were monitored. The impact of such treatment on wood-coating interaction was investigated by evaluating the dynamic wettability and penetration into wood. At the wood surface, plasma streamers were observed more intense on denser latewood regions. Wood mass loss was higher with increasing number of passes through the plasma discharge and was lower for thermally modified wood than for unmodified wood. Plasma treatment increased the surface free energy of all wood species and lowered the contact angles of a waterborne coating, these together indicating enhanced wettability after treatment. Finally, the distribution and penetration depth of the coating were studied with X-ray microtomography. It was found that the coating penetrated deeper into beech than into spruce wood. However, the treatment with plasma increased the penetration of the coating only into spruce wood.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3838
Author(s):  
Marta Borowska-Stefańska ◽  
Michał Kowalski ◽  
Paulina Kurzyk ◽  
Miroslava Mikušová ◽  
Szymon Wiśniewski

The main purpose of this article was to determine the impact on the equilibrium of the local transport system from privileging EVs by permitting them to use bus lanes. The study used two sets of data: information on infrastructure and traffic management; and information on the recorded road network loads and traffic volumes generated by a given shopping centre—the E. Leclerc shopping centre (an important traffic generator within the city of Łódź, Poland). These sets were then used to develop a microsimulation traffic model for the shopping centre and the associated effects on the localised transport system. The model was constructed by means of the PTV Vissim software tool. An initial simulation was conducted that formed a basis for subsequent scenarios (in total, 17 simulations were performed). On the basis of the conducted analyses, it was established that—for the researched part of the transport system—privileging the still rather uncommon battery electric vehicles (BEVs) engendered a marginal deterioration of traffic conditions. At the same time, allowing BEVs to use bus lanes within the chosen research area had no negative impact on bus journey times.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kamrul Ahsan ◽  
Shams Rahman

PurposeThis study conducts a systematic literature review of e-tail product returns research. E-tail product returns are essentially acquisition of products that have been sold through purely online or brick-and-click channels and then returned by consumer to business.Design/methodology/approachUsing a systematic literature review protocol, we identified 75 peer-reviewed articles on e-tail product returns, conducted bibliometric analysis and content analysis of the articles and summarised our findings.FindingsThe findings reveal that the subject of e-tail returns is a new research area; academics have started to investigate several aspects of e-tail returns through different research methodologies and theoretical foundations. Further research is required in leading e-commerce countries and on key areas such as omni-channel returns management, customer satisfaction and service, the impact of resources such as people skills, the benefits of technology and IT systems in managing e-tail returns.Practical implicationsThe study offers a summative account of current e-tail knowledge areas, which can serve as a reference guide for e-tailers to develop strategies for more efficient and competitive product returns.Originality/valueThis study contributes theoretically by developing clusters of key themes or knowledge areas about e-tail returns. It also provides a conceptual framework for e-tail returns management, which can be used as a springboard for further empirical research.


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