◎ Title : Measurement and modeling of crank train friction in light-duty diesel engines
◎ Authors : Seokhwon Lee, Jongdae Kang, Sungwook Park
◎ Journal : Journal of Mechanical Science and Technology
◎ Information : Vol. 34, pp. 889-903, 2020
◎ Keywords : Engine friction, Strip-down method, Friction model, Piston, Journal bearing
◎ Abstract :
In this study, we present measurements and calculations of friction energy loss in the crank train of a light-duty vehicle diesel engine. The main objectives are to estimate the friction loss of each engine component and demonstrate the validity of our MATLAB-based friction modeling method. Friction measurement results obtained through a strip-down method are utilized to separate the entirety of engine friction loss into individual components group. The results from measurements and calculations are compared to verify our friction model. The model considers the lubrication for crank train components through the solution of Reynolds equations. Our friction modeling method is used to analyze the friction characteristics of piston rings, skirts, and main journal bearings with engine load variation. The numerical results show that the friction loss is increased under the high load condition because the contact friction is occurred due to the effect of reduced oil thickness. The experimental results for the variant temperature of the oil and coolant show that lower oil temperature increases the oil viscosity, so it affects the friction increasing.