摘要:

Results of experimental studies of the afterburning of the exhausts of highly boron-loaded, fuel-rich propellants with air and results of boron single particle combustion studies have been examined for definition of limiting processes causing incomplete combustion of boron in typical afterburners, particularly at low afterburner pressure. This examination indicates that ignition of the boron particles, inhibited by the presence of a coating of boron oxide, is likely the controlling process. Transient differential equations describing the generation and removal of oxide and the temperature history of a particle have been derived, converted to difference equation form and programmed for computer solution to permit prediction of whether or not a given particle will ignite and, if it will, the time required for ignition. Predicted ignition times for particles studied by Macek in a flat-flame burner have been compared with his experimental results—reasonably good agreement has been obtained. The program has been used to predict effects of initial boron oxidethickness,particlesize,oxygen partial pressure, initial particle temperature, ambient lemperature, and effective surroundings radiation temperature on ignition time. One important result is the prediction of increased ignition time with decreasing oxygen partial pressure, a result consistent with the observation of low afterburner efficiency at low afterburner pressure.

ISSN:0010-2202    

DOI:10.1080/00102207208952516

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The transient combustion of a liquid fuel droplet which instantaneously reaches its thermodynamic critical state on introduction into a supercritical stagnant oxidizing environment was studied using second order reaction kinetics. The relevant conservation equations were solved numerically for a fuel-oxidizer system consisting of octane and oxygen, with the products of combustion and neutral nitrogen also being involved in the computation. Comparisons were made with previous flame sheet models with respect to burning time and flame zone location. Ignition delay was defined and computed. The distribution of the computed radial mass average velocity is presented and discussed.

ISSN:0010-2202    

DOI:10.1080/00102207208952517

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Results are given for ignition delays of ammonia-oxygen-argon mixtures after shock heating to temperatures between 1570 and 2460 °K. Three pressure regions were used (0.2 to 0.3, 3.3 to 5.3 and 27.2 to 44.4 atm). Absorption spectroscopy showed the presence of NH, OH and NO before explosion. The influence of hydrogen on the system was studied and a mechanism is proposed to explain the results obtained.

ISSN:0010-2202    

DOI:10.1080/00102207208952518

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The dependence of induction times to explosion of shock-heated, argon-diluted mixtures of nitrous oxide with a fuel upon temperature and reactant concentration may be used to discern rate-controlling processes during the ignition delay. A theory, as proposed by Soloukhin, is applied to results obtained when ammonia, methane, carbon monoxide, cyanogen and hydrogen was used as fuel.

ISSN:0010-2202    

DOI:10.1080/00102207208952519

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

ISSN:0010-2202    

DOI:10.1080/00102207208952520

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

ISSN:0010-2202    

DOI:10.1080/00102207208952521

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The report presents some results of experiments which were undertaken with the aim of determining reaction rate data in turbulent diffusion flames of industrial size, burning fuel oil and gas. After a description of the burner systems used, the choice of input parameters which would allow for the evaluation of reaction rate data from locally measured flame properties, is discussed. The change of carbon distribution along the flame axis, as a function of input conditions, is demonstrated, and an effective activation energy for soot formation in propane flame is derived.

ISSN:0010-2202    

DOI:10.1080/00102207208952522

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The Study Group of Natural Gas Flames (G.E.F.G.N.) makes trials on industrial diffusion flames in the Research Station of TOULOUSE. During these investigations some results about soot particles sampled in flames were collected. These soot particles make up the main source of luminosity of flames

ISSN:0010-2202    

DOI:10.1080/00102207208952523

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

A mathematical model predicting the particle size distribution of solid dispersed phase obtained as a product of a reaction between gaseous reactants is proposed. The model assumes that the particle formation occurs in different steps: gas phase reaction, particle nucleation, particle growth via surface reaction and coagulation. Integro-differential equations describing the process are set-up and solved by means of the moments method. As a result expressions for the first two moments of the particle size distribution, giving the particle concentration and the mean particle volume, are obtained as a function of time, reactant initial concentration, and nucleation, surface reaction and coagulation kinetic constants. Some characteristic times of the particles formation process are also derived and discussed.

ISSN:0010-2202    

DOI:10.1080/00102207208952524

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

In most of the studies and theories about soot formation, the starting point of the discussion is the acetylene, disregarding the previous phase which covers the decomposition of the higher hydrocarbons to acetylene

ISSN:0010-2202    

DOI:10.1080/00102207208952525

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor