Influence of biofuels on the internal flow in diesel injector nozzles

In this paper, the behavior of the internal nozzle flow of a standard diesel fuel has been compared against a biodiesel fuel (soybean oil) at cavitating and non-cavitating conditions, using a homogeneous equilibrium model. The model takes into account the compressibility of both phases (liquid and vapour) and use a barotropic equation of state which relates pressure and density to calculate the growth of cavitation. Furthermore, turbulence effects have been introduced using a RNG k-@e model. The comparison of both fuels in a real diesel injector nozzle has been performed in terms of mass flow, momentum flux, effective velocity at the outlet and cavitation appearance. The decrease of injection velocity and cavitation intensity for the biodiesel noticed by numerical simulation at different injection conditions, predict a worse air-fuel mixing process.

[1]  Akio Tomiyama,et al.  Effects of cavitation in a nozzle on liquid jet atomization , 2007 .

[2]  Christopher J. Rutland,et al.  A FULLY COMPRESSIBLE, TWO-DIMENSIONAL MODEL OF SMALL, HIGH-SPEED, CAVITATING NOZZLES , 1999 .

[3]  Fabian Kärrholm Peng.  Numerical Modelling of Diesel Spray Injection and Turbulence Interaction , 2006 .

[4]  Olivier Simonin,et al.  MULTIDIMENSIONAL SIMULATION OF CAVITATING FLOWS IN DIESEL INJECTORS BY A HOMOGENEOUS MIXTURE MODELING APPROACH , 2008 .

[5]  Weixing Yuan,et al.  Numerical Simulation of Two-Phase Flow in Injection Nozzles: Interaction of Cavitation and External Jet Formation , 2003 .

[6]  Raul Payri,et al.  The influence of cavitation on the internal flow and the spray characteristics in diesel injection nozzles , 2004 .

[7]  A. K. Singhal,et al.  Mathematical Basis and Validation of the Full Cavitation Model , 2002 .

[8]  F. J. Salvador,et al.  Comparative analysis of a DI diesel engine fuelled with biodiesel blends during the European MVEG-A cycle: Preliminary study (I) , 2009 .

[9]  D. R. Stinebring,et al.  High Reynolds Number, Unsteady, Multiphase CFD Modeling of Cavitating Flows , 2002 .

[10]  F. J. Salvador,et al.  Validation of a code for modeling cavitation phenomena in Diesel injector nozzles , 2010, Math. Comput. Model..

[11]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[12]  Su Han Park,et al.  An Experimental and Numerical Investigation of Atomization Characteristics of Biodiesel, Dimethyl Ether, and Biodiesel−Ethanol Blended Fuel , 2008 .

[13]  Raul Payri,et al.  Diesel nozzle geometry influence on spray liquid-phase fuel penetration in evaporative conditions , 2008 .

[14]  Sangil Kwon,et al.  An Experimental Study on the Atomization and Combustion Characteristics of Biodiesel-Blended Fuels , 2005 .