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Title: Physical properties of bio-diesel & Implications for use of bio-diesel in diesel engines

In this study we identify components of a typical biodiesel fuel and estimate both their individual and mixed thermo-physical and transport properties. We then use the estimated mixture properties in computational simulations to gauge the extent to which combustion is modified when biodiesel is substituted for conventional diesel fuel. Our simulation studies included both regular diesel combustion (DI) and premixed charge compression ignition (PCCI). Preliminary results indicate that biodiesel ignition is significantly delayed due to slower liquid evaporation, with the effects being more pronounced for DI than PCCI. The lower vapor pressure and higher liquid heat capacity of biodiesel are two key contributors to this slower rate of evaporation. Other physical properties are more similar between the two fuels, and their impacts are not clearly evident in the present study. Future studies of diesel combustion sensitivity to both physical and chemical properties of biodiesel are suggested.
Authors:
 [1] ;  [1] ;  [1] ;  [1] ;  [1]
  1. ORNL
Publication Date:
OSTI Identifier:
974208
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Conference
Resource Relation:
Conference: SAE 2007 Powertrain & Fluid Systems Conference, Chicago, IL, USA, 20071029, 20071101
Research Org:
Oak Ridge National Laboratory (ORNL); Fuels, Engines and Emissions Research Center; National Transportation Research Center
Sponsoring Org:
ORNL LDRD Director's R&D
Country of Publication:
United States
Language:
English
Subject:
33 ADVANCED PROPULSION SYSTEMS; CHEMICAL PROPERTIES; COMBUSTION; COMPRESSION; DIESEL ENGINES; DIESEL FUELS; EVAPORATION; IGNITION; MIXTURES; PHYSICAL PROPERTIES; SENSITIVITY; SIMULATION; SPECIFIC HEAT; TRANSPORT; VAPOR PRESSURE