Effects of Fuel Physical Properties on Diesel Engine Combustion using Diesel and Bio-Diesel Fuels

Document Number: 2008-01-1379

Date Published: April 2008

Author(s):
Youngchul Ra - Univ. of Wisconsin
Rolf D. Reitz - Univ. of Wisconsin
Joanna McFarlane - Oak Ridge National Laboratory

Abstract:
A computational study using multi-dimensional CFD modelling was performed to investigate the effects of physical properties on diesel engine combustion characteristics with bio-diesel fuels. Properties of typical bio-diesel fuels that were either calculated or measured are used in the study and the simulation results are compared with those of conventional diesel fuels. The sensitivity of the computational results to individual physical properties is also investigated, and the results provide information about the desirable characteristics of the blended fuels. The properties considered in the study include liquid density, vapor pressure, surface tension, liquid viscosity, liquid thermal conductivity, liquid specific heat, latent heat, vapor specific heat, vapor diffusion coefficient, vapor viscosity and vapor thermal conductivity. The results show significant effects of the fuel physical properties on ignition delay and burning rates at various engine operating conditions. It is seen that there is no single physical property that dominates differences of ignition delay between diesel and biodiesel fuels. However, among the 11 properties considered in the study, the simulation results were found to be most sensitive to the liquid fuel density, vapor pressure and surface tension through their effects on the mixture preparation processes.

File Size: 1206K
Product Status: In Stock

Included in: V117-4

See other papers presented at SAE World Congress & Exhibition, April 2008, Detroit, MI, USA, Session: CI Engine Performance for Use with Alternative Fuels (Part 3 of 3)

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