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Christian Eigenbrod

Bio: Christian Eigenbrod is an academic researcher from University of Bremen. The author has contributed to research in topics: Ignition system & Combustion. The author has an hindex of 10, co-authored 56 publications receiving 440 citations.


Papers
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Journal ArticleDOI
TL;DR: In this article, a numerical model is developed applying a simplified chemical reaction model that includes the low and the high temperature reactions, which is able to reproduce the two step temperature rise and the roles of the two kinds of reactions on the ignition process up to the establishment of a diffusion flame around the droplet.
Abstract: Experimental and theoretical studies on the spontaneous ignition process of isolated fuel droplets were carried out. Time dependent temperature fields around the igniting droplets were observed by interferometry so that two step temperature rise can be detected. Some experiments are performed under microgravity to obtain reference data. Induction times are examined as a function of ambient temperature. As a result, a zero temperature coefficient region is found, which is equivalent to the NTC (negative temperature coefficient) region for the ignition of premixed gas. A numerical model is developed applying a simplified chemical reaction model that includes the low and the high temperature reactions. The model is able to reproduce the two step temperature rise and the roles of the two kinds of reactions on the ignition process up to the establishment of a diffusion flame around the droplet are examined.

67 citations

Journal ArticleDOI
01 Jan 1996
TL;DR: In this paper, a fuel droplet of n -heptane, n -dodecane, or iso-octane is suddenly exposed in a high-temperature, high-pressure air to ignite.
Abstract: Spontaneous ignition of isolated single fuel droplets in air is investigated. Special attention is given to the transient behavior of chemical reactions. Single-stage and two-stage ignition or cool flame behavior is investigated. A fuel droplet of n -heptane, n -dodecane, or iso -octane is suddenly exposed in a high-temperature, high-pressure air to ignite. The succeeding process is observed by a Michelson interferometer that visualizes the instantaneous temperature field around a droplet. Experiments are done with air of 500–1100 K in temperature and 0.1–2.0 MPa in pressure. Ignition regions are mapped on a temperature-pressure plane and the roles of the low-and high-temperature branches of chemical reactions are described. Induction times and their temperature or pressure dependence are analyzed. The diameter dependence of the induction times shows influences of physical process only on first induction time. Pressure dependence of the second induction time indicates that the dominating factor for the induction time is the nature of a cool flame during the first stage. Mixture conditions at the occurrence of a cool flame and the relation between mixture condition and second induction times are examined. Fuel and temperature dependence of second induction time and TC (zero-temperature coefficient) behavior of total induction time are explained by the dependence of the mixture condition on those parameters through cool flame temperature.

62 citations

Journal ArticleDOI
TL;DR: In this paper, a large-scale flame spread experiment was conducted inside an orbiting spacecraft to study the effects of microgravity and scale and to address the uncertainty regarding how flames spread when there is no gravity and if the sample size and the experimental duration are, respectively, large enough and long enough to allow for unrestricted growth.

59 citations

Journal ArticleDOI
TL;DR: In this article, an international research team has been assembled to reduce the uncertainty and risk in the design of spacecraft fire safety systems by testing material samples in a series of flight experiments (Saffire 1, 2, and -3) to be conducted in an Orbital Science Corporation Cygnus vehicle after it has undocked from the International Space Station (ISS).

57 citations

Journal ArticleDOI
01 Jan 2000
TL;DR: In this paper, a suspended droplet was brought to a high temperature for ignition and the Michelson interferometer detected cool-flame appearance as well as hotflame appearance, and ignition types (no ignition, coolflame only, singlestage ignition, and two-stage ignition) were classified on a Z-Ta map.
Abstract: Spontaneous ignition of isolated two-component fuel droplets has been experimentally studied. The components were n-decane (ND)/1-methylnaphthalene (MN), or ND/1,2,4-trimethylbenzene (TMB). Both are n-alkane/aromatic mixtures, and therefore are candidates for model fuels of multicomponent commercial fuels refined from crude petroleum. ND showed two-stage ignition behavior, while the other two fuels (aromatic hydrocarbons) did not and were less reactive. A suspended droplet was suddenly brought to a high temperature for ignition. Observation by a Michelson interferometer detected cool-flame appearance as well as hot-flame appearance. The ambient gas was air, and the droplet diameter was 0.7 mm. The experimental conditions that were varied were ambient temperature, Ta, (500–1000K), ambient pressure, Pa, (0.1–2.0 MPa), and the initial mole fraction of ND in the liquid phase, Z (0–1). In the case Z≠1, Pa was fixed to 0.3 MPa. Ignition delays for cool-flame and hot-flame appearance (t1 and ttot) and the difference between them (t2) were measured, and ignition types (no ignition, cool-flame only, singlestage ignition, and two-stage ignition) were classified on a “Z-Ta” map. It is common to ND/MN and ND/TMB that two-stage ignition region is narrowed and finally vanishes as Z decreases, and that t1, t2, and ttot all increase monotonically as Z decreases. However, TMB was affected more than MN because of its higher volatility. (Normal boiling point: ND 447.3 K, MN 517.9 K, TMB 442.5 K) Numerical simulation with a fully transient one-dimensional model was employed to help the interpretation.

43 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, the effect of finite thermal conductivity and recirculation in droplets can be taken into account using the so-called parabolic model, which is a reasonable compromise between accuracy and CPU efficiency.

724 citations

Journal ArticleDOI
TL;DR: In this article, the initiation of turbulent non-premixed combustion of gaseous fuels through autoignition and through spark ignition is reviewed, motivated by the increasing relevance of these phenomena for new combustion technologies.

614 citations

Journal ArticleDOI
TL;DR: A review of gas phase detailed kinetic models developed to simulate the low-temperature oxidation and autoignition of gasoline and diesel fuel components (alkanes, ethers, esters, alkenes, cycloalkane, aromatics, including from four atoms of carbon) is presented in this paper.

580 citations

01 Jan 2016
TL;DR: The sfpe handbook of fire protection engineering is universally compatible with any devices to read and is available in the authors' digital library an online access to it is set as public so you can download it instantly.
Abstract: Thank you very much for downloading sfpe handbook of fire protection engineering. Maybe you have knowledge that, people have look numerous times for their favorite books like this sfpe handbook of fire protection engineering, but end up in infectious downloads. Rather than enjoying a good book with a cup of coffee in the afternoon, instead they juggled with some malicious bugs inside their laptop. sfpe handbook of fire protection engineering is available in our digital library an online access to it is set as public so you can download it instantly. Our digital library saves in multiple locations, allowing you to get the most less latency time to download any of our books like this one. Merely said, the sfpe handbook of fire protection engineering is universally compatible with any devices to read.

334 citations

Journal ArticleDOI
TL;DR: In this article, the authors present a state-of-the-art review and an in-depth discussion of pulverized fuels (PF) oxy-fuel combustion fundamentals and their modeling, which underpin the development of this promising technology.

260 citations