摘要:

This investigation was conducted to examine the influence of the flow velocity, turbulence intensity, droplet size distribution and fuel-air ratio on the turbulent flame velocities in premixed sprays. Premixed sprays of kerosene or light diesel oil were burnt either in a combustion chamber 450 mm long and of 75 mm × 75 mm cross section, or on an inverted-cone-flame burner of 21.6 mm diameter. The flame velocities were measured, and the physical structure of flames was observed by schlieren and high-speed photographies.

ISSN:0010-2202    

DOI:10.1080/00102207208952297

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The process of propagation of a turbulent flame into a premixed spray has been studied theoretically. In general, the flame velocity of a premixed flame is presented theoretically as the eigenvalue of a set of differential equations. In this study, a numerical method was adopted in determining the flame velocity as an eigenvalue, so that a theoretical analysis on a rather realistic model, where the droplet size distribution, the temperature dependences of thermal or transport properties and some other factors were taken into account, was possible.

ISSN:0010-2202    

DOI:10.1080/00102207208952298

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The hierarchy of equations describing a special class of turbulent reacting flows is developed and shown to imply some interesting effects of turbulence on chemical behavior. The class of flows is characterized by an oxidizer-fuel-product system undergoing fast chemical reactions so that oxidizer and fuel cannot coexist at a space-time point. There is demonstrated the degeneration of this hierarchy into separate hierarchies when one reactant is totally absent.

ISSN:0010-2202    

DOI:10.1080/00102207208952299

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The structure of a reacting surface in a turbulent flow involving contiguous volumes of fluid with one reactant present and the other absent is studied by an idealized model. The analysis provides estimates of the several length scales involved and distributions of the reactants and product in the neighborhood of such a surface assuming that the diffusivity of species is much less than that of momentum. The analysis also indicates that the coupled dissipation terms arising in Part I must be considered negligibly small in the limit of infinite reaction rates. The results of an experiment involving the turbulent mixing of weak-acid and weak-base solutions are discussed and are shown to provide qualitative support for the picture of reacting surfaces evolving from this study. Salt produced by the reaction was detected using a single electrode conductivity probe with effective diameter about 5 microns.

ISSN:0010-2202    

DOI:10.1080/00102207208952300

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The thermo-mechanical effect on combustion behavior of incorporating inert impurity particles into double-base propellants is investigated. Burning rate and temperature profile measurements of propellants containing various amounts of aluminium oxide powders of different grain sizes indicate that the inclusion of inert impurity particles enhances the burning rate at low pressures, the effect diminishing with increase in pressure. A theoretical model is constructed, based on the assumption that the interfaces created by these particles provide internal burning surfaces which decompose following an Arrhenius relationship. The simple theoretical model predicts the trend of the experimental results, but cannot provide any insight into the contribution of the thermo-mechanical effect to the overall heat of condensed phase reaction in double-base propellants.

ISSN:0010-2202    

DOI:10.1080/00102207208952301

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Product compositions for ammonia/oxygen and ammonia/oxygen/nitrogen premixed, atmospheric pressure flames were experimentally determined. Nitric oxide concentrations in excess of equilibrium levels were observed over the entire experimental equivalence ratio range of 0.40 to 1.85.

ISSN:0010-2202    

DOI:10.1080/00102207208952302

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The behavior of a premixed acetylene-air flame on a slot burner adjacent to a wall is described. The so-called wall reattachment or Coanda effect is seen to occur. The blow-off flow rate is shown to be greater than that obtained with an ordinary slot burner. The results obtained for various slot sizes are demonstrated to correlate approximately when plotted as critical average velocity gradient versus mixture ratio.

ISSN:0010-2202    

DOI:10.1080/00102207208952303

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

An analytical study is presented for the attenuation of visible radiation by carbon smokes as a function of wavelength and particle size distribution. A simple approximate formula that gives an explicit functional relationship among the extinction coefficient and other pertinent physical parameters characterizing smoke clouds have been obtained. Results are discussed with respect to the existing experimental and numerical information.

ISSN:0010-2202    

DOI:10.1080/00102207208952304

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

An analytical technique for the evaluation of combustion stability in rocket motors with partial length acoustic liners is presented. The combustors considered in this work have concentrated combustion zones at the injector, finite mean flows, cylindrical cross sections, and acoustic liners of arbitrary length and impedance. Linear three dimensional oscillations in such combustion chambers are analyzed using an integral equation-iteration technique. Stability limits in terms of the sensitive time lag model are calculated for several values of Mach Number, length to radius ratio, liner impedance, liner length, liner location, and nozzle admittance. Results indicate that increasing liner length increases combustor stability substantially at low Mach Numbers but has a considerably smaller effect for larger Mach Numbers. Increasing Mach Number or length to radius ratio has a destabilizing effect while liner location has only a minor effect on stability.

ISSN:0010-2202    

DOI:10.1080/00102207208952305

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The effect of thermal radiation on the reacting boundary layer is studied analytically. Finite difference solutions to the governing set of boundary layer equations for the conservation of mass, momentum, and energy are presented. Temperature and concentration distributions throughout the boundary layer and wall heat flux are reported, which describe the developing reaction and the radiative effects. The effects of radiation are to broaden the reaction zone, attenuate the maximum temperatures, and displace the apparent flame away from the wall. Radiative emission by the high temperature gases retards the development of the reaction, while the gaseous absorption of the flux emitted from the wall accelerates it. The location of a self-sustaining reaction is shown to be sensitive to the radiation parameters of the flow.

ISSN:0010-2202    

DOI:10.1080/00102207208952306

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor