CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   Main CFD Forum (http://www.cfd-online.com/Forums/main/)
-   -   Radiation in diesel engines (http://www.cfd-online.com/Forums/main/742-radiation-diesel-engines.html)

 Chrys Correa April 21, 1999 08:18

Radiation in diesel engines

Hi!

Does anyone have any experience with modeling radiation heat transfer in diesel engines?? Specifically, any comments regarding the following points will be appreciated:

1) The numerical method used to solve the RTE

2) The radiative properties of the combustion gases and soot (is the gray gas assumption justified or is the spectral dependence important?)

3) Is the optically thin assumption justified?

Any references will be welcomed.

Thanks.

Chrys

 Nuray Kayakol April 21, 1999 11:36

Re: Radiation in diesel engines

Hi, I have no experience with modelling of radiative heat transfer in diesel engines but industrial furnaces and combustors.

some comments: (1) discrete ordinates method as a RTE solver

Ref:M.F. Modest, Radiative Heat Transfer, Mc Graw Hill, Inc,1993 http://michelle.me.psu.edu/ (2) Smith et al.& Leckner total emissivity correlations

for the calculation of absorbtion coefficient of the medium

Ref: T.F Smith, Z.F. Shen, J. N. Friedman, Evaluation of Coefficients for the weighted Sum of gray gases model, J. Heat Transfer, vol 104,1982.

B. Leckner, Spectral and total emissivity of water vapor and carbon dioxide, combustion ans Flame, vol. 19,1972.

Spectral dependency is important but it takes too much timein CFD applications. So total emissivity correlations are used in CFD applications.

Soot:

Magnussen, B.F. and Hjertager, B.H. "On Mathematical Modeling of Turbulent Combustion with Special Emphasis on Soot Formation and Combustion," 16th International Symposium on Combustion, pp. 719-729, The Combustion Institute, 1976.

Khan I.M.and Greeves, G., "A Method for Calculating the Formation of and Combustion of Soot in Diesel Engines," Heat Transfer In Flames, Ed. Afgan and Beer, pp. 391-404, 1974.

Nuray

 All times are GMT -4. The time now is 04:44.