A new simple model for the puffing and micro-explosion of composite multi-component water/liquid fuel droplets is suggested. This model is based on the assumption that a spherical water sub-droplet is located in the centre of a spherical fuel droplet. The effects of droplet thermal swelling are considered; the Abramzon and Sirignano model is applied for the analysis of droplet heating and evaporation. It is assumed that puffing/micro-explosion starts when the temperature at the water/liquid fuel interface becomes equal to the water nucleation temperature. Assuming that the species diffusion coefficient is constant at each time step, the equation for species diffusion inside the droplet is solved analytically. Raoult's law at the surface of the droplet is used. The analytical solution to the equation for species diffusion is incorporated into the numerical code alongside the previously obtained analytical solution to the equation for heat transfer inside the droplet. Both solutions are used at each time step in the calculations. The model is used for the analysis of puffing/micro-explosion of kerosene/water droplets. The experimentally observed and predicted times to puffing/micro-explosion are shown to be reasonably close, decrease with increasing ambient gas temperatures and increase with increasing initial droplet radii. Taking into account the presence of multiple components in fuel leads to longer times to puffing/micro-explosion compared to the case when kerosene is approximated by cycloundecane (the dominant component in kerosene).
|Number of pages
|International Journal of Heat and Mass Transfer
|Published - 8 Dec 2021
Bibliographical noteFunding Information:
The authors are grateful for the financial support received from the Russian Science Foundation (Grant 21-19-00876), which supported S. S. Sazhin (who contributed to the development of the physical and mathematical models, analysis of the results and preparation of the text of the paper), E. Shchepakina and V.A. Sobolev (who contributed to the development of the mathematical model), Scholarship from the President of the Russian Federation (Grant SP-447.2021.1) which supported D. Antonov (who performed the experiments and applied the model to their analysis), and the National Research Tomsk Polytechnic University (project VIU-ISHFVP-60/2019) which supported P.A. Strizhak (who contributed to the preparation of the experiments and the analysis of the results).
© 2021 Elsevier Ltd
- Composite droplets
- multi-component fuel
- species diusion equation
- Species diffusion equation
- Multi-component fuel