With the application of high-pressure fuel injection and fuel post-injection technology of diesel engine, the dilution problem of lubricating oil caused by fuel becomes more and more serious, and temperature has a significant effect on the fuel viscosity. Therefore, establishing a viscosity model considering temperature and fuel dilution is of great significance to the study of lubricating oil performance and the simulation of diesel engine friction pairs. Taking Mobil 15W-40 lubricant of diesel engine as an example, the viscosity changes of different lubricants between 20 ℃ and 180 ℃ were measured by experiment including 15W-40 lubricant and its blends with 3%, 6%, 9%, 12% and 15% volume fraction of fuel. Vogel, Andrade and Reynolds equations considering fuel volume fraction were built and their fitting effects were compared. The dimensionless dilution viscosity ratio-temperature equation was constructed to reflect the influence degree and law of fuel dilution on viscosity at different temperatures. A back-propagation neural network viscosity model based on lubricating oil temperature and mixed fuel volume fraction was finally constructed. The results show that Vogel equation has the best fitting effect for the viscositytemperature curve of 15W-40 lubricating oil before and after dilution. For the predicted viscosity of 15W-40 lubricating oil of back-propagation neural network viscosity model, the error is less than 2% among the range of 90% and does not exceed 6% in a whole.
WANG Tianqi
,
WANG Yaning
,
ZHANG Bin
,
TIAN Ye
,
LIU Xiaori
. Viscosity Model of Diesel Engine Lubricating Oil-Based on Temperature and Fuel Dilution[J]. Vehicle Engine, 2023
, 0(3)
: 28
-34
.
DOI: 10.3969/j.issn.1001-2222.2023.03.005
