Frictional Losses Induced by the Piston-Assembly, Piston Rings and Piston Skirt

Principal Investigator: Nabil Chalhoub, Wayne State University, nchalhoub@eng.wayne.edu
Faculty: Naeim A. Henein, Wayne State University
Student: Nasim Khaled, Mohannad Hakeem, Manan Trivedi, John Foehr, Wayne State University
Government: Peter Schihl, U.S. Army TARDEC
Industry: Bogdan Nitu, AVL
Mohannad Hakeem, Chrysler Group LLC
Hassan Nehme, Ford Motor Co.

Work began in 2008 and was completed in 2013.

The intricate dynamics of the piston-assembly has a significant effect on the performance of internal combustion (IC) engines. It is widely recognized that the piston-assembly is a major contributor to frictional losses, which have a detrimental effect on the engine fuel economy. Moreover, the intricate dynamics of the piston-assembly tend to significantly influence the thermal efficiency through blow-by, the engine durability through wear, the engine noise through piston-slap, and the oil consumption through improper sealing. Therefore, the focus of this project is to develop a reliable tool for predicting the intricate dynamics of the piston-assembly and for determining the frictional losses induced by its various lubrication regimes. Such a tool provides engine designers and manufacturers with valuable insights into the dynamic behavior and the lubrication regimes of the piston-assembly. Given the breadth and the complexity of the proposed study, the work was performed in the following phases:

  • Phase I: Development of a module that is capable of predicting the dynamic behavior of the crank-slider mechanism. This module accounts for the piston primary and secondary (piston-slap and piston-tilting) motions.
  • Phase II: Development of a module that focuses on the intricate dynamics of the ring-pack. This extends the scope of this module to account for both twisting and out-of- plane transverse deformations of the rings.
  • Phase III: This phase concentrates on the solid-fluid interaction between the piston assembly and the lubricating oil film. Its main objective is to determine the normal pressure distribution in the lubricating oil film and the friction forces exerted on the piston-assembly.
  • Phase IV: Use the developed tool to assess the effects of ring-pack profile and various engine operating conditions on the piston-assembly frictional losses, lubrication regimes, engine blowby, wear, and noise.
  • Phase V: Use the developed tool to assess the effects of ring-pack profile and various engine operating conditions on the piston-assembly frictional losses, lubrication regimes, engine blowby, wear, and noise.
Publications:
  • C. Fadel, N. G. Chalhoub, G. A. Kfoury, N. A. Henein, "Direct Measurement of the Piston-Assembly Friction Force in a Single Cylinder Engine Under Motoring Conditions", Proceedings of ASME Dynamic Systems and Control Conference, Paper No. DSCC2008-2173, Ann Arbor, Michigan, USA, October 20-22, 2008.
  • N. G. Chalhoub, W. Edelby, "Piston Secondary Motions and Hydrodynamic Lubrication Regime in a Single Cylinder Internal Combustion Engine", Proceedings of ASME Dynamic Systems and Control Conference, Paper No. DSCC2008-2171, Ann Arbor, Michigan, USA, October 20-22, 2008.
  • K. Giscard, N. G. Chalhoub, "Computation of the Instantaneous Frictional Losses of Internal Combustion Engine Components", Proceedings of the ASME Dynamic Systems and Control Conference, Cambridge, Massachusetts, September 13-15, 2010.
  • G. Kfoury, N. G. Chalhoub, "Computation of the Instantaneous Frictional Losses of Internal Combustion Engine Components," Proceedings of the 2010 ASME Dynamic systems and Control Conference (DSCC2010), Cambridge, Massachusetts, September 12-15, 2010.
  • M. Hakeem, N. G. Chalhoub, P. Schihl, "Dynamic model of the piston-ring assembly using curved beam finite elements", Proceedings of the ASME Dynamic Systems and Control Conference and Bath/ASME Symposium on Fluid Power & Motion Control, Arlington, Virginia, Oct 31 - Nov 2, 2011.
  • Hakeem, M., 2011, “Intricate Dynamics and Frictional Losses of the Piston-Ring Assembly in High Power Density Diesel Engines,” Ph.D. Dissertation, Mechanical Engineering Department, Wayne State University.