Prediction of the structure of fuel sprays in cylindrical combustion chambers

The structure of fuel sprays in cylindrical combustion chambers is theoretically investigated using computer models of current interest. Three representative spray models are considered: 1) a locally homogeneous flow (LHF) model, which assumes infinitely fast interphase transport rates; 2) a deterministic separated flow (DSF) model, which considers finite rates of interphase transport but ignores effects of droplet/turbulence interactions; and 3) a stochastic separated flow (SSF) model, which considers droplet/turbulence interactions using stochastic methods. Various flow conditions are considered to examine the influence of droplet size and swirl strength on the spray flame structure. Comparison of calculated results with the experimental data shows that general features of the flow structure can be predicted with reasonable accuracy using the two separated flow models. In contrast, the LHF model overpredicts the rate of development of the flow. It is found that large swirl is associated with a high rate of evaporation and intensive turbulent mixing and combustion. Increased droplet diameter produces a longer flame length and reduces combustion intensity when compared to smaller initial droplet diameters.

[1]  C. Mao,et al.  Evaluation of a locally homogeneous flow model of spray combustion , 1980 .

[2]  H. Moneib,et al.  Effect of combustion air swirl on the flow pattern in a cylindrical oil fired furnace , 1977 .

[3]  Sanford Gordon,et al.  Computer program for calculation of complex chemical equilibrium compositions , 1972 .

[4]  J. Dukowicz.  A particle-fluid numerical model for liquid sprays , 1980 .

[5]  G. Faeth.  Evaporation and combustion of sprays , 1983 .

[6]  Essam E. Khalil,et al.  Aerodynamic and thermodynamic characteristics of kerosene-spray flames , 1977 .

[7]  Robert W. Bilger.  Turbulent jet diffusion flames , 1976 .

[8]  W. Sirignano.  Fuel droplet vaporization and spray combustion theory , 1983 .

[9]  S. Jeng,et al.  Species Concentrations and Turbulence Properties in Buoyant Methane Diffusion Flames , 1984 .

[10]  Gerard M. Faeth,et al.  Measurements and predictions of the structure of evaporating sprays , 1985 .

[11]  Chung King Law,et al.  Recent advances in droplet vaporization and combustion , 1982 .

[12]  A. D. Gosman,et al.  COMPUTER ANALYSIS OF FUEL-AIR MIXING IN DIRECT-INJECTION ENGINES , 1980 .

[13]  A. Gosman,et al.  Aspects of Computer Simulation of Liquid-Fueled Combustors , 1983 .

[14]  Gerard M. Faeth,et al.  Drop-turbulence interactions in a diffusion flame , 1985 .

[15]  J. Whitelaw,et al.  Experimental study of the interaction between a fuel spray and surrounding combustion air , 1981 .

[16]  G. Faeth,et al.  Evaluation of a Locally Homogeneous Flow Model of Spray Evaporation , 1979 .

[17]  Gerard M. Faeth,et al.  Structure of nonevaporating sprays. II - Drop and turbulence properties , 1985 .

[18]  James H. Whitelaw,et al.  Calculation of the Flow Properties of a Confined Kerosene-Spray Flame , 1980 .

[19]  G. Faeth,et al.  Structure of nonevaporating sprays. I - Initial conditions and mean properties , 1985 .

[20]  Gerard M. Faeth,et al.  Structure of particle-laden jets - Measurements and predictions , 1984 .

[21]  Clayton T. Crowe,et al.  Review—Numerical Models for Dilute Gas-Particle Flows , 1982 .