scholarly journals Light-Induced ignition of Carbon Nanotubes and energetic nano-materials: a review on methods and advanced technical solutions for nanoparticles-enriched fuels combustion

2020 ◽  
Vol 59 (1) ◽  
pp. 26-46 ◽  
Author(s):  
Paolo Visconti ◽  
Patrizio Primiceri ◽  
Roberto de Fazio ◽  
Luciano Strafella ◽  
Antonio Ficarella ◽  
...  

AbstractAim of the present manuscript is to provide an overview of all possible methods and light source typologies used by the different research groups for obtaining the energetic nano-materials’ photo-ignition, showing the latest progress related to such phenomenon employing, also, alternative radiation sources to the common Xe lamp. In fact, the employment of a different source typology can open new usage prospects respect to those enabled by the Xe lamp, mainly due to its technological limitations. Therefore, several studies are faced to test light sources, such as lasers and LEDs, for igniting the nano-energetic materials (as CNTs mixed with metallic catalyzers, Al / CuO nano-particles, etc); these nano-materials are usefully employed for starting, in volumetric and controlled way, the combustion of air-fuel mixtures inside internal combustion engines, leading to significant benefits to the combustion process also in terms of efficiency, reliability, and emissions of pollutants. Several research works are presented in literature concerning the ignition of liquid / gaseous fuels, without nano-particles, employing laser sources (i.e laser-based plugs in place of the common spark plugs); therefore, an innovative solution is proposed that employs multi-point laser-plugs for inducing the ignition of nano-materials dispersed into the air-fuel mixture inside the cylinder, so further improving the combustion of the fuel in an internal combustion engine.

Author(s):  
Jiang Lu ◽  
Ashwani K. Gupta ◽  
Eugene L. Keating

Abstract Numerical simulation of flow, combustion, heat release rate and pollutants emission characteristics have been obtained using a single cylinder internal combustion engine operating with propane as the fuel. The data are compared with experimental results and show excellent agreement for peak pressure and the rate of pressure rise as a function of crank angle. The results obtained for NO and CO are also found to be in good agreement and are similar to those reported in the literature for the chosen combustion chamber geometry. The results have shown that both the combustion chamber geometry and engine operating parameters affects the flame growth within the combustion chamber which subsequently affects the pollutants emission levels. The code employed the time marching procedure and solves the governing partial differential equations of multi-component chemically reacting fluid flow by finite difference method. The numerical results provide a cost effective means of developing advanced internal combustion engine chamber geometry design that provides high efficiency and low pollution levels. It is expected that increased computational tools will be used in the future for enhancing our understanding of the detailed combustion process in internal combustion engines and all other energy conversion systems. Such detailed information is critical for the development of advanced methods for energy conservation and environmental pollution control.


2019 ◽  
Vol 178 (3) ◽  
pp. 182-186
Author(s):  
Zbigniew SROKA ◽  
Maciej DWORACZYŃSKI

The modification of the downsizing trend of internal combustion engines towards rightsizing is a new challenge for constructors. The change in the displacement volume of internal combustion engines accompanying the rightsizing idea may in fact mean a reduction or increase of the defining swept volume change factors and thus may affect the change in the operating characteristics as a result of changes in combustion process parameters - a research problem described in this publication. Incidents of changes in the displacement volume were considered along with the change of the compression space and at the change of the geometric degree of compression. The new form of the mathematical dependence describing the efficiency of the thermodynamic cycle makes it possible to evaluate the opera-tion indicators of the internal combustion engine along with the implementation of the rightsizing idea. The work demonstrated the in-variance of cycle efficiency with different forms of rightsizing.


2021 ◽  
pp. 146808742110442
Author(s):  
Sebastian Welscher ◽  
Mohammad Hossein Moradi ◽  
Antonino Vacca ◽  
Peter Bloch ◽  
Michael Grill ◽  
...  

Due to increasing climate awareness and the introduction of much stricter exhaust emission legislation the internal combustion engine technology faces major challenges. Although the development and state of technology of internal combustion engines generally reached a very high level over the last years those need to be improved even more. Combining water injection with a diesel engine, therefore, seems to be the next logical step in developing a highly efficient drive train for future mobility. To investigate these potentials, a comprehensive evaluation of water injection on the diesel engine was carried out. This study covers >560 individual operating points on the test bench. The tests were carried out on a single-cylinder derived from a Euro 6d four-cylinder passenger car with the port water injection. Furthermore, a detailed pressure trace analysis (PTA) was performed to evaluate various aspects regarding combustion, emission, etc. The results show no significant effects of water injection on the combustion process, but great potential for NOx reduction. It has been shown that with the use of water injection at water-to-fuel rates of 25%, 50%, and 100%, NOx reduction without deterioration of soot levels can be achieved in 62%, 40%, and 20% of the experiments, respectively. Furthermore, water injection in combination with EGR offers additional reduction in NOx emissions.


Author(s):  
Xiaojian Yang ◽  
Guoming G. Zhu ◽  
Zongxuan Sun

The combustion mode transition between SI (spark ignited) and HCCI (Homogeneously Charged Compression Ignition) of an IC (Internal Combustion) engine is challenge due to the thermo inertia of residue gas; and model-based control becomes a necessity. This paper presents a control oriented two-zone model to describe the hybrid combustion that starts with SI combustion and ends with HCCI combustion. The gas respiration dynamics were modeled using mean-value approach and the combustion process was modeled using crank resolved method. The developed model was validated in an HIL (Hardware-In-the-Loop) simulation environment for both steady-state and transient operations in SI, HCCI, and SI-HCCI hybrid combustion modes through the exhaust valve timing control (recompression). Furthermore, cooled external EGR (exhaust gas re-circulation) was used to suppress engine knock and enhance the fuel efficiency. The simulation results also illustrates that the transient control parameters of hybrid combustion is quite different from these in steady state operation, indicating the need of a control oriented SI-HCCI hybrid combustion model for transient combustion control.


2019 ◽  
Vol 178 (3) ◽  
pp. 27-37 ◽  
Author(s):  
Denys STEPANENKO ◽  
Zbigniew KNEBA

The mathematical description of combustion process in the internal combustion engines is a very difficult task, due to the variety of phenomena that occurring in the engine from the moment when the fuel-air mixture ignites up to the moment when intake and exhaust valves beginning open. Modeling of the combustion process plays an important role in the engine simulation, which allows to predict in-cylinder pressure during the combustion, engine performance and environmental impact with high accuracy. The toxic emissions, which appears as a result of fuels combustion, are one of the main environmental problem and as a result the air pollutant regulations are increasingly stringent, what makes the investigation of the combustion process to be a relevant task.


2020 ◽  
Vol 8 (6) ◽  
pp. 2076-2080

Internal combustion engine powered vehicles are widely used all around the world for mobility. Scooter is the most commonly used two-wheeler by people of all age groups due to its easy handling and riding comfort. Due to gearless transmission, the mileage of scooter is low compared to gear transmission bikes. Nowadays increase in petrol price makes the mileage as the most important factor for internal combustion engines. Using lean air-fuel mixture for combustion in a engine increases the mileage as well as reduces the pollution. The air-fuel ratio is said to be lean when the ratio of air-fuel is greater than 15:1, the stoichiometric ratio of air-fuel is 14.7:1. In this Study, the clearance between the piston and cylinder of a 125cc engine is reduced from 0.5mm to 0.25mm to run in lean air-fuel mixture. The lean fuel-air mixture is achieved by supplying extra air into the engine by making an additional hole in the carburetor outlet and the air is supplied through it. The excess air is supplied to the engine after the vehicle reaches above 40 kilometer per hour. The extra air supply is controlled by an solenoid valve which is actuated by an electronic circuit. The lean mixture usage increases the engine temperature more than usual and it is controlled by using synthetic engine oil. The result shows increase in mileage from 40 - 45 kilometer per litre to 50 - 60 kilometer per litre and reduction in the emission of Carbon monoxide (CO) and Hydrocarbon (HC). Thus an overall increase in mileage is about 15 - 20% from existing vehicle but emission of Nitrogen Oxides (NOX) is slightly higher than usual. Combustion of lean air-fuel mixture produces less torque hence it cannot be used to move the vehicle from rest position, so lean mixture must be supplied to the engine after the vehicle reaches certain speed


Author(s):  
Jiang Lu ◽  
Ashwani K. Gupta ◽  
Eugene L. Keating ◽  
Andrew A. Pouring

Abstract Numerical simulation of flow, combustion phenomena and pollutants emission characteristics have been obtained on an homogeneous-charged internal combustion engine having conventional flat piston and five other bowl-in-piston geometries. The code employed here uses the time marching procedure and solves the governing partial differential equations of multi-component chemically reactive flow by finite difference method. The transient solution is marched out in a sequence of time steps. The results show that the piston geometry affects the local flame properties which subsequently influences the pollutants emission level. The numerical results provide a cost effective means of developing advanced internal combustion engine chamber geometry design that provides high efficiency and low pollution. It is expected that increased computational tools will be used in the future for enhancing our understanding of the detailed combustion process in internal combustion engines and all other energy conversion systems. Such detailed information is critical for the development of advanced methods for energy conservation and environmental pollution control.


Author(s):  
Ashwani K. Gupta ◽  
Lu Jiang ◽  
Eugene L. Keating

Abstract Numerical simulation of flow, combustion phenomena and pollutants emission characteristics have been obtained on an internal combustion engine having conventional flat piston and advanced piston geometries. The code employed the time marching procedure that solves the governing partial differential equations of multi-component chemically reactive fluid flow by finite difference method. The transient solution is marched out in a sequence of time steps. The results show that both the piston geometry and inlet flow conditions affects the local flame properties which subsequently alters the pollutants emission levels. The numerical results provide a cost effective means of developing advanced internal combustion engine chamber geometry design that provides high efficiency and low pollution levels. It is expected that increased computational tools will be used in the future for enhancing our understanding of the detailed combustion process in internal combustion engines and all other energy conversion systems. Such detailed information is critical for energy conservation and environmental pollution control.


Author(s):  
L. Andreassi ◽  
A. L. Facci ◽  
S. Ubertini

As a consequence of the endless price growing of oil, and oil derivate fuels, automotive industry is experiencing a concerning decreasing in sales. Accordingly, in order to meet customer needs, there is every day a greater interest in solutions for increasing engine efficiency. On the other hand the growing attention to environmental problems leads to increasingly restrictive regulations, such as European EURO 4 and EURO 5. Direct injection of gaseous fuel has emerged to be a high potential strategy to tackle both environmental and fuel economy requirements. However since the electronic gaseous injection technology is rather new for automotive applications, limited experience exists on the optimum configuration of the injection system and the combustion chamber. To facilitate the development of these applications computer models are being developed to simulate gaseous injection, air entrainment and the ensuing combustion. This paper introduces a new method for modelling the injection process of gaseous fuels in multi-dimensional simulations. The proposed model allows holding down grid requirements, thus making it compatible with the three-dimensional simulation of an internal combustion engine. The model is validated and calibrated by comparing numerical results with available experimental data. To highlight the potential applications, some numerical results of the three-dimensional combustion process in a gas engine are presented.


2008 ◽  
Vol 132 (1) ◽  
pp. 3-16
Author(s):  
Jerzy MERKISZ ◽  
Marek WALIGÓRSKI

The article concerns the possibilities of use of the method being able to assess of the combustion process and its lack in internal combustion engines of railway traction vehicles, that bases on the use of vibration signal parameters. The paper includes the results of research conducted on the engine test bench with a single cylinder research and compression-ignition engine with direct injection, and tests for the engine of a diesel locomotive in the exploitation condition. Possibility of the vibration signal estimators application to the assessment of a combustion process lack in an internal combustion engine and a high reliability of combustion process diagnostics basing on the above method have been proved.


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