摘要:

The effect of the nitrogen content on the ignition characteristics of nitrocellulose (NC) is investigatedusing thin films ranging in nitrogen content from 11.40%to 13.88%. Both the ignition energies and the condensed phase reactions are measured and analyzed. The ignition energy (E) measured in an arc image furnace at constant pressure, using samples coated with carbon is found to be 0.4 cal cm−2for all 10 micron thick specimens, regardless of both the nitrogen content and the radiant flux density. It was found that when the film thickness is less than 20 microns, the temperature within the film is practically uniform enabling a simple computation of the ignition temperature. The calculated temperature at one atmosphere is approximately 290 °C. The radiant heat transfer aspects of ignition are analyzed by comparing the ignition energy of uncoated sample films with those surface coated with carbon, and with films where carbon is uniformly distributed throughout the matrix.

ISSN:0010-2202    

DOI:10.1080/00102207308952336

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

This paper presents experimental results on the burning of square and round rods and flat plates of wood in methanol flames. The dependence of the burning time and weight-loss rate on the initial thickness of the specimens was investigated. The size dependence of the burning elements was found to be practically independent of the environmental conditions. Central temperature histories and mass loss curves of the burning cylinders were correlated with initial diameter.

ISSN:0010-2202    

DOI:10.1080/00102207308952337

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

Under certain conditions, a heat source applied to the free surface of an aqueous solution will produce (a) rapid surface flow from all directions towards the region of contact (b) a rise in the surface below the heat source (c) a downward current from the elevation. A theoretical analysis of the phenomenon is provided under the assumptions that the process takes place in a shallow layer under steady-state conditions, the induced flow being two-dimensional and symmetrical about a vertical plane in which the heat source is assumed to lie. The process is shown to be characterised by a discriminant which depends on the rates of heat and mass transfer along the layer, Prandtl, Schmidt and Reynolds numbers and the Marangoni numbers for temperature and concentration changes.

ISSN:0010-2202    

DOI:10.1080/00102207308952338

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

A simple analytical basis for determining the total emissivity of luminous flames is developed. The analysis considers flames whose dominant emitting species are water vapor, carbon dioxide and soot particles. Calculations are made to illustrate the relative importance of gas and soot emission under typical flame conditions.

ISSN:0010-2202    

DOI:10.1080/00102207308952339

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

An ideal combustor composed of a fuel-air mixing zone followed by a perfectly stirred reactor (PSR) and a series of plug-flow reactors is studied to determine emission levels of NOxCO, unburned hydrocarbons and soot. It is concluded that these emissions can be reduced to negligible levels provided the stirred reactor is operated at high mass loading rates (Q = ṁ/P2V) and mixing is perfectly controlled. Fuel and air must be premixed before entering the PSR and local φ must be less than 1.2. Perfect stirring in the PSR is necessary. A controlled amount of dilution air is instantaneously added at the PSR exit to quench NO formation but not CO and hydrocarbon oxidation.

ISSN:0010-2202    

DOI:10.1080/00102207308952340

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor