- Author
-
Kerstein, A. R.
- Title
- Prediction of the Concentration PDF for Evaporating Sprays.
- Coporate
- Sandia Labs., Livermore, Calif.
- Report
-
WSS/CI 83-34,
- Book or Conf
- Combustion Institute/Western States Section. Spring Meeting, 1983. April 11-12, 1983,
Pasadena, CA,
53 p.,
1983
- Keywords
-
concentration; evaporation; sprays
- Abstract
- A model of an evaporating spray is proposed in which each droplet deposits vapor along a linear trajectory through a quiescent host gas. The trajectories and vaporization rates of droplets are assumed to be random and uncorrelated. It is assumed that the radial concentration profile about each trajectory relaxes to a Gaussian form. Under these assumptions, explicit relationships are obtained between the probability density function (pdf) for concentration and the parameters governing individual-droplet processes. These results provide a very efficient method for numerical computation of the pdf, which may enhance the capabilities of spray modeling codes. Furthermore, the concentration pdf is predicted to exhibit several distinctive features. In particular, when the mean width of the radial concentration profiles is equal to the mean spacing of trajectories, the pdf is predicted to consist of a plateau plus a decresing tail. It is shown that this and related features are characterisric of randomly distributed cylindrical diffusers, and therefore may occur in a variety of spray configurations.