摘要:

Experimental work has demonstrated that the internal combustion engine exhaust emissions can be controlled through a two-stage combustion process, achieved with a relatively simple modification. The engine is fitted with a small prechamber in the normal spark plug hole. This small chamber burns a spark-ignited fuel-rich mixture, which in. turn ignites a fuel-lean mixture in the main chamber with a flame. Overall air-fuel ratios as high as 29:1 were attained, with smooth engine performance and only a 20% power loss. The engine speeds ranged from 1800 to 2800 rpm; the loads varied from 20% to 100% of maximum. The carbon monoxide was reduced by as much as five orders of magnitude, the oxides of nitrogen by 50–75 %, and the hydrocarbons by 40–50 % from levels measured in the basic engine at the same compression ratio and test points.

ISSN:0010-2202    

DOI:10.1080/00102207208952321

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The ignition of aluminum particle streams was studied in a steady-flow experiment in which aluminum powder carried in oxygen was ignited by a propane-oxygen pilot flame. Two measured particle size distributions were used, with average diameters of 25 μ and 120μ. Particle-to-gas weight fractions were in the range from 0.1 to 0.5. Ignition times were deduced from flame photographs and high-speed motion pictures were used to follow the ignition event.

ISSN:0010-2202    

DOI:10.1080/00102207208952322

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

An experimental investigation of ammonium perchlorate (AP)-binder (PBAA) sandwich combustion was made in standard and high acceleration environments. An optically equipped combustion bomb mounted on a centrifuge and a standard combustion bomb were used in the investigation. High speed color motion pictures and schlieren were taken during the combustion process. Principal results were: binder thickness as little effect upon regression rate; sandwich combustion is acceleration sensitive and results in part from binder melt/AP deflagration interaction; below the low pressure deflagration limit (Pdt) of ammonium perchlorate the sandwich combustion process is laminar with combustion continuing for large distances above the binder/AP interface; above thePdtof AP the sandwich combustion process appears to be turbulent and consists of two distinct flame regions.

ISSN:0010-2202    

DOI:10.1080/00102207208952323

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

An asymptotic analysis, in the limit of large activation energies, is presented for the ignition of a solid propellant undergoing an exothermic heterogeneous Arrhenius reaction with a gaseous oxidizer. The analysis is carried out for hypergolic or shock tube ignition conditions, and also for ignition under a radiant flux with in-depth absorption of the radiation.

ISSN:0010-2202    

DOI:10.1080/00102207208952324

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

A new calorimeter of balanced heat transfer type for the spark energy measurement has been designed and tested, and the calorimeter has been proved to exhibit a satisfactory performance, in accuracy and reproducibility of the measurements, as compared with conventional calorimeters of transient heat transfer type. The construction, experimental procedure and some results of this new type of calorimeter are described. Theoretical relations, which explain the results and will be helpful in the design of this type of calorimeter for different heat input and size, are also introduced.

ISSN:0010-2202    

DOI:10.1080/00102207208952325

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The disposal of logging slash by burning is an important forest management tool. Selection of optimal burning methods involves a trade between considerations of economics and fire control and those of air pollution potential. Among controllable variables are the intensity of burning and various chemical treatments of the fuel, such as the addition of flame retardants. Deduction of optimal strategies on the basis of field burning experience alone is hampered by inability to independently vary those parameters which control the pyrolysis of the fuel, and through this the formation of air pollutants. This paper describes a laboratory simulation of wood pyrolysis under field burning conditions, in which the thermal environment experienced by burning fuel elements can be arbitrarily controlled. This apparatus is capable of imposing ranges of incident radiant flux and ambient air flow rate for a cylindrical wood specimen. Outputs are the specimen weight loss rate and particulate air pollutant production rate. For the results reported here, the fuel was Douglas fir doweling, both plain and treated with the flame retardant “Phos-Chek,” principally diammonium phosphate. Observed combustion patterns tend to become independent of fuel conditions and retardant treatment at relatively high environmental temperatures. At lower temperatures, combustion patterns are difficult to reproduce, and are very sensitive to flame retardant treatment. On the basis of the limited data so far available, no evidence has been found that flame retardant treatment under otherwise controlled conditions results in reduction of air pollutants.

ISSN:0010-2202    

DOI:10.1080/00102207208952326

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor