Enhancement of Energetic Materials Combustion Process

Author(s):  
Rene Francisco Boschi Goncalves ◽  
Koshun Iha ◽  
José A. F. F. Rocco

Fuels and energetic materials enhancements have been focus of several studies in the past few years, as the sole development of the engines (design, structure of the combustion chambers and stronger materials) leads to a limited efficiency. One of the most effective ways of enhancing the energetic capabilities of a fuel is via enrichment with a highly reactive species, such as hydrogen and ozone, as these materials significantly increase the reaction mechanism kinetics, enabling the occurrence of faster reactions and increasing the temperature of the chamber. The present chapter aims to summarize some of the applications of fuel enrichment and the so far achieved results, focusing in internal combustion engines and systems for automotive, energy-generation or aerospace applications.

Author(s):  
Randy P. Hessel ◽  
Ettore Musu ◽  
Salvador M. Aceves ◽  
Daniel L. Flowers

A computational mesh is required when performing CFD-combustion modeling of internal combustion engines. For combustion chambers with moving pistons and valves, like those in typical cars and trucks, the combustion chamber shape changes continually in response to piston and valve motion. The combustion chamber mesh must then also change at each time step to reflect that change in geometry. The method of changing the mesh from one computational time step to the next is called rezoning. This paper introduces a new method of mesh rezoning for the KIVA3V CFD-combustion program. The standard KIVA3V code from Los Alamos National Laboratory comes with standard rezoners that very nicely handle mesh motion for combustion chambers whose mesh does not include valves and for those with flat heads employing vertical valves. For pent-roof and wedge-roof designs KIVA3V offers three rezoners to choose from, the choice depending on how similar a combustion chamber is to the sample combustion chambers that come with KIVA3V. Often, the rezoners must be modified for meshes of new combustion chamber geometries to allow the mesh to successfully capture change in geometry during the full engine cycle without errors. There is no formal way to approach these modifications; typically this requires a long trial and error process to get a mesh to work for a full engine cycle. The benefit of the new rezoner is that it replaces the three existing rezoners for canted valve configurations with a single rezoner and has much greater stability, so the need for ad hoc modifications of the rezoner is greatly reduced. This paper explains how the new rezoner works and gives examples of its use.


2020 ◽  
Vol 21 (1) ◽  
pp. 14-19
Author(s):  
Arthur R. Asoyan ◽  
Igor K. Danilov ◽  
Igor A. Asoyan ◽  
Georgy M. Polishchuk

A technical solution has been proposed to reduce the consumption of basic hydrocarbon fuel, to improve the technical, economic and environmental performance of internal combustion engines by affecting the combustion process of the fuel-air mixture with a minimum effective mass fraction of hydrogen additive in the fuel-air mixture. The burning rate of hydrogen-air mixtures is an order of magnitude greater than the burning rate of similar mixtures based on gasoline or diesel fuel, compared with the former, they are favorably distinguished by their greater detonation stability. With minimal additions of hydrogen to the fuel-air charge, its combustion time is significantly reduced, since hydrogen, having previously mixed with a portion of the air entering the cylinder and burning itself, effectively ignites the mixture in its entirety. Issues related to the accumulation of hydrogen on board the car, its storage, explosion safety, etc., significantly inhibit the development of mass production of cars using hydrogen fuel. The described technical solution allows the generation of hydrogen on board the car and without accumulation to use it as an additive to the main fuel in internal combustion engines. The technical result is to reduce the consumption of hydrocarbon fuels (of petroleum origin) and increase the environmental friendliness of the car due to the reduction of the emission of harmful substances in exhaust gases.


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.


2019 ◽  
Vol 294 ◽  
pp. 05001
Author(s):  
Patryk Urbański ◽  
Maciej Bajerlein ◽  
Jerzy Merkisz ◽  
Andrzej Ziółkowski ◽  
Dawid Gallas

3D models of Szymkowiak and conventional engines were created in the Solidworks program. During the motion analysis, the characteristics of the piston path were analyzed for the two considered engine units. The imported file with the generated piston routes was used in the AVL Fire program, which simulated combustion processes in the two engines with identical initial conditions. The configurations for two different compression ratios were taken into account. The basic thermodynamic parameters occurring during the combustion process in internal combustion engines were analyzed.


1929 ◽  
Vol 33 (228) ◽  
pp. 1139-1166

During the past quarter of a century great strides have been made in perfecting the science of aviation. Too much credit cannot be given to the men who have laboured untiringly in the laboratories in an endeavour to determine with mathematical certainty the physical laws that govern the mechanical devices which mankind is using in his conquest of the air.Science has done more for civil aviation, however, than unravel the mysteries of aerodynamics and internal combustion engines. It has provided many important aids to air navigation, such as improved lighting facilities for airways and airports, wireless as a means of communication between ground and aeroplane, and also as a beacon to guide the pilot on his course, and numerous instruments which now adorn the cockpit of every aeroplane.While at times the development of air transport may suffer because of lack of co–ordination between the laboratory and the factory, it will suffer far more should a similar condition exist between the scientists and those charged with the duty of regulating and promoting civil aviation.


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.


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