摘要:

A model is developed for calculating NO emissions for stratified charge engines in which the fuel is completely vaporized prior to combustion. The validity of the model is limited to single chamber geometry as it does not treat bulk gas motion typical of prechamber or divided chamber designs. The parameters of the model are fuel type, humidity of inlet air, overall equivalence ratio, stratification function, per cent EGR, intake manifold pressure, intake manifold temperature, compression ratio, piston connecting rod to crank radius ratio, RPM, and position and duration of combustion in the cycle.

ISSN:0010-2202    

DOI:10.1080/00102207308946627

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

Measurements of NO exhaust emissions have been made on a single-cylinder engine with and without stratification. The results were compared with predictions based on an existing computer model of Blumberg (1973). Combustion duration, a critical parameter of the model, was inferred from experimental pressure-time records for each condition studied.

ISSN:0010-2202    

DOI:10.1080/00102207308946628

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

The Texaco Controlled-Combustion System, a stratified charge concept utilizing a coordinated arrangement of air swirl, fuel injection and positive ignition, has been shown over many years of development in numerous engine conversions to produce excellent fuel economy, inherently low exhaust emissions and the ability to prevent combustion knock without regard to fuel octane or cetane number. Recent work has demonstrated the capability of the system to meet the very stringent emission levels of the 1976 U.S. Federal Standards for light duty vehicles and the potential to maintain these levels during 50,000 miles of testing.

ISSN:0010-2202    

DOI:10.1080/00102207308946629

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

A theoretical model of turbulent flame propagation in a reciprocating stratified charge engine is developed and calculations of temperature and species concentrations as functions of space and time are made. Also pressure is calculated as a function of time. A spacial variation of mixture ratio is considered such that there is a fuel-rich region in the center of the cylinder and a fuel-lean region near the cylinder walls. The spark in the fuel-rich region results in a premixed-type of flame propagating toward the walls. A diffusion-type flame results in the wake of the other flame due to the mixing of the excess air and fuel.

ISSN:0010-2202    

DOI:10.1080/00102207308946630

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

A one-dimensional model for the spark ignition two-phase, stratified Wankel engine combustion is presented. The injected liquid fuel is assumed to break up into droplets whose vaporization and motion are computed, together with the changes of the gas phase variables, by solving a coupled system of equations made up of an appropriately simplified form of the spray equation and the conservation equations for the gas phase. The model makes use of a Weber number/Reynolds number correlation for the computation of the initial drop radius, of Stokes' drag equation for the droplet motion, of a Ranz-Marshall type vaporization rate equation for the droplet vaporization, of a one-step second order reaction rate equation for the combustion of the gaseous fuel, of a turbulent diffusivity for heat and mass transfer, and of a McAdams type correlation for the wall heat transfer rate. Results are presented for a specific engine configuration. Although general conclusions cannot be derived, it would appear that the model should be valuable to the design engineer who wants to control this complex combustion problem.

ISSN:0010-2202    

DOI:10.1080/00102207308946631

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

A small quantity of light diesel oil injected into the combustion chamber of a spark-ignition engine running on a fuel vapor (propane)-air mixture was found to improve the engine performances for lean mixture ratios and to reduce the emissions of nitric oxide and carbon monoxide considerably. That is, the indicated horsepower (or indicated mean effective pressure) was increased by 6 to 16 per cent for a constant operating condition and a constant mixture ratio, while the region of stable operation was extended up to an extremely large overall air-fuel ratio well greater than twenty. Consequently, both the emission of nitric oxide and that of carbon monoxide were reduced simultaneously. The concentration of nitric oxide in the exhaust gas for the mean effective pressure of 5 kp/cm2, for example, was reduced down to 200 ppm, ca. one tenth of the value obtained for propane-air operation without light oil injection, while the concentration of carbon monoxide was reduced down to ca. 0.08 per cent by volume.

ISSN:0010-2202    

DOI:10.1080/00102207308946632

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

The ignition of kerosine fuel sprays in a flowing air stream was studied experimentally. Ignition was accomplished using electrical sparks whose energy level could be varied in steps between 19.3 and 130 millijoules. Tests were carried out at air velocities up to 46 metres/second on five simplex swirl atomizers designed to produce fuel drops ranging from 30 to 120 microns in diameter.

ISSN:0010-2202    

DOI:10.1080/00102207308946633

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor