Last edited by Daizilkree
Saturday, July 11, 2020 | History

3 edition of Mechanisms of combustion limits in premixed gas flames at microgravity found in the catalog.

Mechanisms of combustion limits in premixed gas flames at microgravity

Mechanisms of combustion limits in premixed gas flames at microgravity

final report, 12/15/88 - 12/17/91

  • 281 Want to read
  • 37 Currently reading

Published by National Aeronautics and Space Administration, National Technical Information Service, distributor in [Washington, DC, Springfield, Va .
Written in English

    Subjects:
  • Reduced gravity environments.,
  • Combustion -- Effect of reduced gravity on.

  • Edition Notes

    Statementprincipal investigator, Paul D. Ronney.
    Series[NASA contractor report] -- NASA CR-194557., NASA contractor report -- NASA CR-194557.
    ContributionsUnited States. National Aeronautics and Space Administration.
    The Physical Object
    FormatMicroform
    Pagination1 v.
    ID Numbers
    Open LibraryOL14701020M

    Over the past two decades, microgravity combustion research has focused primarily on increasing our understanding of fundamental combustion processes (e.g., droplet combustion, soot production, flame spread, smoldering and gas jet flames). This research program has been highly successful and was aided by synergistic programs in Europe and in Japan. Achieving microgravity 11 Candle flame as an example of gravitational influences on combustion 27 Premixed-gas Flames / P.D. Ronney 35 Comparison of time scales 37 Flammability limits 40 Flame instabilities 48 Stretched and curved flames 53 'Cool flames' 67 Turbulent flames 70

    The effects of unburned-gas temperature on the characteristics of cellular premixed flames generated by hydrodynamic and diffusive-thermal instabilities in large space: fractal dimension of cellular-flame fronts. Journal of Thermal Science and Technology, Vol. 12, Issue. 1, p. JTST A laser schlieren system which uses video recording and digital images analysis has been developed and applied successfully to microgravity combustion experiments performed in a drop-tower. The optical system and the experiment are installed within a small package which is subjected to free-fall. The images are recorded on video tape and are digitized and analyzed .

      Premixed conical CH4-air flames were studied experimentally and numerically under normal straight, reversed gravity conditions and microgravity. Low-gravity experiments were performed in Drop tower. Classical Bunsen-type burner was used to find out features of gravity influence on the combustion processes. Mixture equivalence ratio was varied from . Microgravity combustion research review One of the first books published on microgravity combustion is entitled Combustion Experiments in a Zero-Gravity Laboratory, edited by Thomas H. Cochran 4. The authors presented many great ideas on investigating combustion in microgravity. However, the book offered very little.


Share this book
You might also like
Days

Days

Netaji, the man

Netaji, the man

A history of the Far East in modern times.

A history of the Far East in modern times.

Evaluation in education

Evaluation in education

prophylaxis of post-partum haemorrhage

prophylaxis of post-partum haemorrhage

Neurology of infancy and childhood.

Neurology of infancy and childhood.

Forecasting the mountain wave.

Forecasting the mountain wave.

Transport phenomena.

Transport phenomena.

Immunology at a glance

Immunology at a glance

Birth registration

Birth registration

Plays about the presidents

Plays about the presidents

Richard Nixon

Richard Nixon

More than a bed...

More than a bed...

Man and his lifebelts

Man and his lifebelts

Never Seduce a Scoundrel (The School for Heiresses, Book 1)

Never Seduce a Scoundrel (The School for Heiresses, Book 1)

Mechanisms of combustion limits in premixed gas flames at microgravity Download PDF EPUB FB2

“Combustion is also an area where compressible reactive phases benefit from microgravity studies to reveal mechanisms and isolate basic behaviors that feed more accurate models.

ClavinInfluence of hydrodynamics and diffusion upon the stability limits of laminar premixed flames. (), pp. Google Scholar. P.D Cited by: 2. MECHANISMS OF COMBUSTION LIMITS IN PREMIXED GAS FLAMES AT MICROGRAVITY (NASA-Lewis Grant No.

NAG) 12/15/88 - 12/17/91 Principal Investigator: Paul D. Ronney Department of Mechanical and Aerospace Engineering Princeton Univerity, Princeton, NJ (current address: Department of Mechanical Engineering University of Southern California. @article{osti_, title = {Studies of premixed laminar and turbulent flames at microgravity.

Final report, 15 March August }, author = {Ronney, P.D.}, abstractNote = {A two and one-half year experimental and theoretical research program on the properties of laminar and turbulent premixed gas flames at microgravity was conducted.

propagating spherically expanding premixed gas flames at microgravity (tzg) conditions exhibit a flammability limit with a very low burning velocity at the limit and an unstable mode of flame prop- agation at sub-limit conditions, termed Self-Extin- guishing Flames or SEFs, which do not occur at earth gravity.

from non-premixed flames (e.g., gas-jet flames, liquid fuel droplet flames, fire spread over solid fuel beds) is the fact that (with the exception of “flame balls” discussed in section ) in.

The second chapter on premixed flames by Paul Rooney begins with a discussion of the salient time scales significant in microgravity combustion and deals with buoyancy effects on flammability limits, flame instabilities, stretched and curved flames, cool flames, and turbulent flames.

Experiments on counterflow flames of CH 4 /O 2 /CO 2 mixtures (Le = ) under microgravity and normal gravity fields were conducted to examine the combustion limit, near-limit extinction boundary and flame regimes of low-Lewis-number premixed flames.

1-D steady state computations on counterflow flames and flame balls were additionally. In addition to microgravity studies, modeling of premixed-gas flames with reabsorption is relevant to combustion at high pressures and in large furnaces because frequently s.

For example, at 40 atm, a typical pressure for premixed-charge internalcom-bustion engines, s ’ 1 for cylinders of radius 4 cm. Similarly, s. 1 in atmospheric. Book Description. Extensively using experimental and numerical illustrations, Combustion Phenomena: Selected Mechanisms of Flame Formation, Propagation, and Extinction provides a comprehensive survey of the fundamental processes of flame formation, propagation, and extinction.

Taking you through the stages of combustion, leading experts visually display. Extensively using experimental and numerical illustrations, Combustion Phenomena: Selected Mechanisms of Flame Formation, Propagation, and Extinction provides a comprehensive survey of the fundamental processes of flame formation, propagation, and extinction.

Taking you through the stages of combustion, leading experts visually display, mathematically explain, and. Get this from a library. Mechanisms of combustion limits in premixed gas flames at microgravity: final report, 12/15//17/ [Paul D Ronney; United States. National Aeronautics and Space Administration.].

Mechanisms of combustion limits in premixed gas flames at microgravity. By Paul D. Ronney. Abstract. A three-year experimental and theoretical research program on the mechanisms of combustion limits of premixed gasflames at microgravity was conducted.

Progress during this program is identified and avenues for future studies are discussed. Purchase Flashback Mechanisms in Lean Premixed Gas Turbine Combustion - 1st Edition. Print Book & E-Book. ISBNIn addition to microgravity studies, modeling of premixed-gas flames with reabsorption is relevant to combustion at high pressures and in large furnaces because frequently τ>1.

For example, at 40 atm, a typical pressure for premixed-charge IC engines, τ≈1 for cylinders of. Laminar burning velocities and flammability limits of premixed flames in the presence of various inert gases including helium, argon, nitrog en and carbon dioxide were investigated by.

Combustion and Flame(); the extension of this mechanism to n -heptane: Fuel(). Clarifications of Quasi-Steady Cool Flames Results from Peters et al. CTM 18 ()   Combustion Engineering, a topic generally taught at the upper undergraduate and graduate level in most mechanical engineering programs, and many chemical engineering programs, is the study of rapid energy and mass transfer usually through the common physical phenomena of flame oxidation.

It covers the physics and chemistry of this process and the. This book provides an introduction to understanding combustion, the burning of a substance that produces heat and often light, in microgravity environments-i.e., environments with very low gravity such as outer space.

Readers are presented with a compilation of worldwide findings from fifteen years of research and experimental tests in various low-gravity environments, including 1/5(1). "On the Mechanisms of Flame Propagation Limits and Extinction Processes at Microgravity," Twenty Second Symposium (International) on Combustion, Combustion Institute,pp.

Ronney, P. D., "Effect of Chemistry and Transport Properties on Near-Limit Flames at Microgravity," Combustion Science and Technology, Vol. 59, pp. The high‐Lewis number (Le) diffusive‐thermal instability in premixed gas combustion is studied experimentally in tubes using lean C 4 H 10 –O 2 –He mixtures (Le≊).

Two self‐excited instabilities are observed for flames propagating in a tube open at the ignition end and closed at the other end: (1) a combined spiral wave and radial pulsation and (2) a pure radial pulsation.

User Tools. Cart. Sign In.related to the experimental and theoretical study of combustion limits in premixed flames at microgravity, as discussed in the following sections.

These topics include: • Radiation effects on premixed gas flames • Flame structure and stability at low Lewis number the mechanisms of flame extinction in the SFLT is not well understood. The.microgravity facility mentioned above. The objective is to understand the extinguishing processes of premixed methane-air flames by various inert gases and to provide better validity of the current C/H/O reaction mechanism for laminar flame propagation, especially in the near-limit region where flame temperature and burning velocity are low.