Suscripción a Biblioteca: Guest
Proceedings of CHT-08 ICHMT International Symposium on Advances in Computational Heat Transfer
May, 11-16, 2008, Marrakesh, Morocco

DOI: 10.1615/ICHMT.2008.CHT


ISBN Print: 978-1-56700-253-9

ISSN: 2578-5486

HYDRODYNAMIC AND KINETIC MODELS OF DROPLET HEATING AND EVAPORATION: ANALYSIS AND APPLICATIONS

page 21
DOI: 10.1615/ICHMT.2008.CHT.120
Get accessGet access

SINOPSIS

A review of recently developed models for fuel droplet heating, evaporation and break-up, suitable for implementation into computational fluid dynamics (CFD) codes, and the applications of these models to simulate the processes in Diesel engines is presented. These models and a specially developed version of a reduced chemical autoignition model, developed by a group of researchers from Shell Research Ltd (known as Shell model), were implemented into the KIVA II CFD code. The autoignition delay time is sensitive to the choice of liquid phase models for droplet heating, but not sensitive to the choice of gas phase models. It was recommended that the effective thermal conductivity liquid phase model and the gas phase model, taking into account the effects of finite thickness of the thermal boundary layer, be used for the simulation of the autoignition process in Diesel engines. The relatively small contribution of thermal radiation to droplet heating can justify the description of the effects of radiation using a simplified model, which does not include the variation of radiation absorption inside the droplets. Recently developed kinetic models for droplet heating and evaporation into a high pressure background gas (air) are described. The application of the rigorous kinetic model, taking into account the heat flux in the kinetic region, is recommended when accurate predictions of the values of droplet surface temperature and evaporation time are essential. In the case of stationary droplets, coupled solutions of the heat conduction equation for gas and liquid phases are reviewed. If the initial stage of droplet heating can be ignored then the steady-state solution for the gas phase can be applied for the analysis of droplet heating. The previously developed dynamic decomposition technique for the solution of ordinary differential equations describing droplet heating and evaporation and the ignition of the fuel vapour/air mixture is briefly described.

Portal Digitalde Biblioteca Digital eLibros Revistas Referencias y Libros de Ponencias Colecciones Precios y Políticas de Suscripcione Begell House Contáctenos Language English 中文 Русский Português German French Spain