The New Method for Simulation of Bulk Condensation of Supersaturated Vapor

Author(s):  
N. M. Kortsenshteyn ◽  
A. K. Yastrebov

The method of direct numerical solution of the kinetic equation for the droplet size distribution function is presented. This new method which is not restricted by the Knudsen number was developed using the analogy with a similar method of solution of the Boltzmann kinetic equation. The simulation of vapor behavior at fast creation of supersaturation state in vapor-gas mixture by means of adiabatic expansion was carried out for the verification of the method. The results obtained by this method were compared with those which were obtained by using the method of moments over a broad range of Knudsen number. The effect of the interphase heat transfer and dependence between saturation pressure and droplet size on the dynamics of condensation relaxation was studied.

2001 ◽  
Vol 124 (1) ◽  
pp. 182-185 ◽  
Author(s):  
Jianming Cao

Droplet size distribution function and mean diameter formulas are derived using information theory. The effects of fuel droplet evaporation and coalescence within combustion chamber on the droplet size are emphasized in nonreactive diesel sprays. The size distribution function expressions at various spray axial cross sections are also formulated. The computations are compared with experimental data and KIVA-II code. A good agreement is obtained between numerical and experimental results. Droplet size distribution and mean diameter at various locations from injector exit and at various temperature conditions are predicted. The decreases of droplet number and variations of mean diameter are computed at downstream and higher temperature.


1999 ◽  
Vol 20 (1-2) ◽  
pp. 187-196 ◽  
Author(s):  
Per Arild Kjølseth Andresen ◽  
Xiaoli Yang ◽  
Johan Sjöblom ◽  
Harald Linga ◽  
Finn P. Nilsen

Author(s):  
A. A. Sidorov ◽  
A. K. Yastrebov

Objective. Integrating the numerical solution module of the kinetic equation for the droplet size distribution function in a CFD package. Application of the module to volumetric condensation at the supersonic flow of a vapor-gas  mixture through a nozzle in a two-dimensional formulation, comparison of  the results with experimental data of third-party authors.Methods. In this  paper, the problem of volume condensation in the supersonic flow of a vapor-gas mixture through a nozzle is solved by finite element methods in a two-dimensional formulation using user-defined functions.Results. A module for the numerical solution of the kinetic equation for the droplet size distribution function is presented as a user-defined function integrated into the calculated CFD package.Conclusion. The module application to volumetric condensation for a vapor-gas mixture flow through the nozzle gave a qualitative agreement in all areas and a quantitative agreement in the area of intense condensation with  measurement data. The distributions of temperatures, pressures, and  the degree of supersaturation are presented both along the central axis and  on the plane bounded by the contour of the computational domain. It is shown that the module does not depend on the solver type (stationary or non-stationary).


Sign in / Sign up

Export Citation Format

Share Document