Effects of Ring Pack Friction Heat on Temperature Fields of Piston Set-Liner

摘要

To investigate the temperature fields of piston set-liner under the friction heat of ring pack, it is established a friction heat allocation model of ring pack based on the heat transfer theory of semi-infinite body. In this model, the piston ring, lubrication film and liner are treated as a three-layer medium. Furthermore, the distribution model of ring pack friction heat, the unsteady heat-mixed lubrication and friction model of piston ring-liner, and the heat transfer model of piston assembly-liner are also built and coupled with the allocation model to develop a coupled heat transfer model of piston set-liner. Employing the model for 6110 diesel engine, the effects of ring pack friction heat on the temperature fields of piston set-liner are simulated. Numerical results demonstrate that the friction heat allotted to the piston ring, lubrication film and liner accounts for nearly 47 %, 21 % and 32 % of ring pack friction heat, respectively. Due to the effects of friction heat, the maximum temperature rises on the piston ring, piston and liner surfaces run approximately up to 8.5 degrees C, 5 degrees C and 5 degrees C, separately. The established allocation and distribution models related to friction heat in this paper can be applied to any type of piston set-liner and provide the theoretical foundation for the optimal design of piston ring-liner.