178,267 research outputs found
Some numerical considerations in the simulation of low-Ma number hydrogen/air mixing layers
No full textRebecca Owston, Vinicio Magi and John Abraha
A numerical study of thermal and chemical effects in interactions of n-heptane flames with a single surface
No full textRebecca Owston, Vinicio Magi and John Abraha
Fuel-air mixing characteristics of DI hydrogen jets
No full textRebecca Owston, Vinicio Magi and John Abrahamhttp://saeeng.saejournals.org/content/1/1/693.abstrac
Transient deformation and drag of decelerating drops in axisymmetric flows
No full textExtent: 20p.Transient deformation and drag coefficients of decelerating drops in axisymmetric flows are numerically computed. The drag coefficients are compared with those of solid spheres. In the case of drops, the behavior of the drag coefficient is dependent on the deformation and internal circulation of the drops in addition to the factors which are important for solid spheres. These, in turn, are dependent on the gas-based Weber number (Weg) and the Ohnesorge number (Ohl). At the relatively low Weg of 1, when the deformation is small, the drag coefficients are about the same for the solid sphere and drop. When Weg is increased, the deformation increases and the difference increases. At the highest Weg of 100, the drop reaches a point of secondary breakup. In general, oblate shapes result in greater drag and prolate shapes in lower drag relative to the solid sphere. Increasing Ohl, which implies increasing viscous forces in the liquid relative to surface tension forces, leads to less deformation and hence lesser differences between solid and drop drag coefficients for a given Weg.Amrita R. Wadhwa, Vinicio Magi and John Abraha
Interactions of hydrogen flames with walls: Influence of wall temperature, pressure, equivalence ratio, and diluents
No full textThe thermal and chemical effects of one-dimensional, premixed hydrogen flames quenching against a single surface are studied numerically using a detailed chemical mechanism. The results for stoichiometric H₂–O₂ flames impinging on a 750 K inert wall agree qualitatively with prior published results. Other wall boundary conditions studied include an adiabatic wall and isothermal walls with temperatures ranging from 298 to 1200 K. Chemical pathway analysis of the detailed hydrogen mechanism reveals the growing importance of radical recombination reactions near the inert walls for increasing wall temperature. Implementation of a H, O, and OH radical sink at the surface of a 750 K isothermal wall results in significantly lower heat generation near the surface. Investigations of various gas properties include changes to equivalence ratio (0.7–2.0), chamber pressure (1 and 2 bar), and inert gas (N₂) addition.R. Owston, V. Magi, J. Abraha
A study of flame-vortex interactions in the presence of residual gases
No full textIn this work the effects of residual combustion products from a prior injection on flame extinction characteristics in a Diesel fuel pulse are investigated through a fundamental study. A numerical code with sixth-order accurate spatial discretization and multiple-step chemical kinetics is used to simulate flame-vortex interactions under Diesel conditions in the presence of residual combustion product mixtures. The results indicate that there is a balance between the heating effect of the high-temperature combustion products that enhance flame stability and the dilution effect of the reduced oxygen concentration, which promotes extinction. These counteracting aspects of the entrained combustion products can lead to an ideal dwell time between multiple injection events for optimum benefits in flame stability.Jonathan W. Anders, Rishikesh Venugopal, Vinicio Magi, and John Abraha
Experience with Rule Induction and k-Nearest Neighbour Methods for Interface Agents that Learn
No full textInterface Agents are being developed to assist users with a variety of tasks. To perform effectively, such agents need knowledge of user preferences. An agent architecture has been developed which observes a user performing tasks, and identifies features which can be used as training data by a learning algorithm. Using the learned profile, an agent can give advice to the user on dealing with new situations. The architecture has been applied to two different information filtering domains: classifying incoming mail messages (Magi) and identifying interesting USENET news articles (UNA). This paper describes the architecture and examines the results of experimentation with different learning algorithms and different feature extraction strategies within these domains
R. C. Zaehner. The Teachings of the Magi. A Compendium of Zoroaslrian Beliefs
No full textGignoux Philippe. R. C. Zaehner. The Teachings of the Magi. A Compendium of Zoroaslrian Beliefs. In: Revue de l'histoire des religions, tome 191, n°1, 1977. p. 98
Book review. Munson R 2004: Raising the Dead: Organ Transplants, Ethics and Society. Oxford: Oxford University Press. 288p. GBP12.99 (PB). ISBN 0 19 517801 7
No full textDopo di te con la pistola
No full textRomanzo di culto in Inghilterra, dove il suo autore viene giudicato "all'altezza di Hammet e Chandler e, in certi casi, addirittura meglio" ("Times Literary Supplement"), "Dopo di te con la pistola", che con altre due opere fa parte della "Trilogia di Mortdecai", ci offre una storia irresistibile dove gli ingredienti canonici del noir si mescolano mirabilmente a battute eleganti, sottintesi sarcastici, citazioni colte
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