Analytical study on the effects of compression speed on the auto-ignition prediction in PCCI combustion

2021 ◽  
Vol 2021.59 (0) ◽  
pp. 08a4
Author(s):  
Kaoru Miyoshi ◽  
Kenji Yoshida
1974 ◽  
Vol 16 (2) ◽  
pp. 88-94 ◽  
Author(s):  
G. A. Karim ◽  
M. Rashidi ◽  
M. Taylor

A large portion of the literature about the use of hydrogen as a fuel in air-breathing reciprocating engines is devoted to the problems of auto-ignition and knock. Operation with oxygen-enriched air or pure oxygen, which in principle can reduce or even eliminate the production of oxides of nitrogen, is expected to be potentially more troublesome in this respect. The paper describes an analytical approach, incorporating detailed chemical kinetics, to the combustion of H2-O2-N2 mixtures in a reciprocating engine. The role of various operating parameters was determined primarily in relation to the length of the ignition delay and the associated peak values of cylinder pressure and temperature. Also, the extent of production of oxides of nitrogen in the exhaust was examined in terms of cycle parameters and the oxygen index of the charge.


Author(s):  
Ramzi Ben Abdallah ◽  
Vishal Sethi ◽  
Pierre Q. Gauthier ◽  
Andrew Martin Rolt ◽  
David Abbott

Liquid hydrogen is considered a technically feasible fuel for all gas turbine applications including propulsion systems [1]. However, the exceptional combustion properties of hydrogen will make fundamental changes to gas turbine combustion systems essential. Micromixing, with a novel cross-flow fuel-injection feature and a large plurality of injection holes offers miniaturised diffusive combustion without the risk of auto-ignition or flashback. A detailed analytical study has been performed to explore combustion behaviour of hydrogen in the micro-diffusion combustor concept. The aims are to investigate a broad range of analytical tools and sensitivities related to hydrogen micromix combustion numerical modelling. Comparative studies based on a number of RANS and LES simulations were carried out to down-select suitable numerical models for species transport, turbulence, chemistry and thermochemistry. Simulation results were found to be particularly sensitive to the species diffusion effects. The study was then extended to identify proper thermal boundary conditions capable of replicating experimental work. A thorough discussion of the findings is provided. The study has generated a novel micromix-injector geometry promising to yield ultra-low NOx emissions. This paper sheds light on the difficulties encountered in modelling the combustion of a gaseous fuel (hydrogen) in a novel micro-diffusion combustion chamber and suggests effective approaches to overcome them. It also identifies additional benefits related to hydrogen as a fuel.


This research article focuses on the theme of violence and its representation by the characters of the novel “This Savage Song” by Victoria Schwab. How violence is transmitted through genes to next generations and to what extent socio- psycho factors are involved in it, has also been discussed. Similarly, in what manner violent events and deeds by the parents affect the psychology of children and how it inculcates aggressive behaviour in their minds has been studied. What role is played by the parents in grooming the personality of children and ultimately their decisions to choose the right or wrong way has been argued. In the light of the theory of Judith Harris, this research paper highlights all the phenomena involved: How the social hierarchy controls the behaviour. In addition, the aggressive approach of the people in their lives has been analyzed in the light of the study of second theorist Thomas W Blume. As the novel is a unique representation of supernatural characters, the monsters, which are the products of some cruel deeds, this research paper brings out different dimensions of human sufferings with respect to these supernatural beings. Moreover, the researcher also discusses that, in what manner the curse of violence creates an inevitable vicious cycle of cruel monsters that makes the life of the characters turbulent and miserable.


Author(s):  
Anfal Muayad Mayoof

Hospitals are the major contributor to environmental corruption and the biggest drain onenergy in their life cycle because they are complex, multifunctional giant facilities. Several recent studieshave been carried out to find the most suitable solutions to reduce energy consumption provide it on-siteand contribute to supporting economic, environmental and social aspects. The reason for the slowmovement of green buildings for hospitals is to focus on a suitable design for the complex function thatdeals with the local climate, natural resources, economy and cultural values and avoid the one-size-fits alldesign. This made the solutions used multiple and varied, different for greening of the hospital and put theresearch in the absence of a clear perception of the mechanisms of the application of green architecture inhospitals and this identified the problem of research. Therefore, the study looked at an analytical study ofexisting project models designed according to the strategies and standards of green architecture todetermine the strategies adopted in each project, and by adopting the analytical method after determiningthe strategy used in each building to achieve the green architecture and then comparing them according tothe standards adopted using the global LEED system Green Building Council. The results that will bereached are the mechanisms of applying Green Architecture to Hospitals.


2011 ◽  
Vol 3 (8) ◽  
pp. 386-389
Author(s):  
Dr. K. Sadasivan Dr. K. Sadasivan ◽  
◽  
S. Kavitha S. Kavitha ◽  
Britto A Britto A

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