Autoignition in nonpremixed flow

The objective of this investigation has been to improve understanding of autoignition processes in nonpremixed flow fields of the types encountered in Diesel-engine ignition, through theoretical analyses that employ asymptotic methods of applied mathematics. The work was intended to develop formulas and equations that can be used in activities of applied research, such as code development, aimed at providing tools useful for the design of Diesel engines. The formulas may also be used directly for ignition estimates.Characteristic time scales were identified for these ignition problems. Their relative magnitudes were employed to define different regimes of ignition and to obtain simplified partial differential equations that describe ignition in these regimes. Effects of turbulence on ignition were addressed. Special attention was devoted to unsteady mixing layers, involving both variable strain and variable pressure, for which ignition-time formulas were derived. In addition, ignition analyses were completed for variable-volume chambers with arbitrary initial spatial variations of temperature and composition, to determine pressure histories produced by ignition-front propagation. These studies were based on one-step, Arrhenius approximations for the chemical kinetics and were restricted to ignition stages that precede ordinary flame propagation. Additional work considered triple-flame propagation that can odcur in mixing layers after ignition, with this same chemical-kinetic description, and asymptotic analysis of n-heptane ignition on the basis of a four-step, semi-empirical model for the chemical kinetics. In this latter study, the region of negative effective overall activation energy, between 800 K and 1100 K, was identified as exhibiting unusual ignition dynamics, and the asymptotic ignition-time formulas were shown to give good agreement with predictions of numerical integrations. This research has helped to strengthen the foundations of ignition theory for nonuniform media. It provided simplified descriptions of ignition processes that can be employed in studies of Diesel combustion that are oriented more towards development than are the present investigations. The asymptotic methods employed in this work thus appear capable of providing quite useful results

Educational work of the Worcester museums

Thesis (M.A.)--Boston University, 1946. This item was digitized by the Internet Archive

Prospectus, September 1, 1993

https://spark.parkland.edu/prospectus_1993/1012/thumbnail.jp

The Evening Herald (Albuquerque, N.M.), 03-19-1919

https://digitalrepository.unm.edu/abq_eh_news/2594/thumbnail.jp

Tucumcari News Times, 08-19-1911

https://digitalrepository.unm.edu/tucumcari_news/1405/thumbnail.jp

Mount Vernon Democratic Banner October 27, 1871

Mount Vernon Democratic Banner was a newspaper published weekly in Mount Vernon, Ohio. Until 1853, it was published as the Democratic Banner.https://digital.kenyon.edu/banner1871/1045/thumbnail.jp

Space shuttle: Heat transfer rate measurements on Convair booster (B-15B-2) and North American Rockwell orbiter (161B) at nominal Mach number of 8

Plotted and tabulated data from the thin-skin thermocouple phase of an experimental test program are presented. These data are representative of three events of simulated flight and are described as booster-orbiter ascent heating data, booster reentry heating data, and orbiter reentry heating data. The test was conducted in a 50-inch hypersonic tunnel b at a nominal Mach number of 8 and free-stream Reynolds number range of 700,000 to 3,700,000 per foot. The model employed was a 0.009 scale replica of the Convair B-15B-2 booster and North American Rockwell 161B orbiter

Horace and his Greek originals

Typescript.it is the purpose of this thesis to give specific examples of Horace's indebtedness to Greek originals in the first book of Odes. The term Greek originals, as used here, includes those parts of ante-Horatian literature, written in the Greek language, which he has translated, whose spirit he has caught, or whose thought he has imitated. Hence the classification of these collected examples is made, in respect to the degree of indebtedness, into the following divisions: 1) Lines which are unconscious echoes of the Greek, 2) lines which consciously imitate the Greek, 3) poems unconsciously imitative of Greek spirit or thought, 4) poems consciously imitative of the Greek, and 5) poems translated.--Page 1.Includes bibliographical references (pages 224-228)

New Mexico State Record, 07-09-1920

https://digitalrepository.unm.edu/nm_state_record_news/1208/thumbnail.jp