Performance Analysis Of Two-Dimensional Section Of Partially Textured Piston Ring With Cavitation Boundary Conditions

The lubrication problems for cavitation are solved using the Elrod algorithm/its modifications, which are extremely nonlinear in nature due to binary switch function, lead to convergence issues, consequently, prone to numerical instabilities. In the present study, a continuous switch function is used to avoid these issues, which has not been explored yet for investigating performance behaviours (minimum film thickness, friction force, and power-loss) of piston ring/cylinder liner pair. The modified Reynolds equation is discretized using the Finite Difference Method (FDM). The algebraic equations have been solved by employing the Elrod and Vijayaraghavan-Keith algorithm with a modified switch function proposed by Fesanghary-Khonsari, which satisfies the mass-conservative cavitation. On the other hand, the total computational domain plays a significant role in predicting accurate numerical results. Therefore, in the present investigation, a piston ring segment of 3 mm x 1.20 mm has been investigated, which comprises larger computational domains ever considered in previous studies. The textures are cylindrical and situated at both ends of the piston ring, leaving the center portion untextured in the axial direction. The minimum film thickness change with time (squeeze film action) and lubricant's (SAE 20W-40 engine oil) viscosity change with operating temperature have been incorporated in the spectrum of this study. The textured piston ring demonstrated an increase up to 7.2% of the minimum film thickness, friction reduction up to 30%, and reduction in power-loss up to 11% compared to the conventional (un-textured) piston ring.