Numerical Analysis of Deterministic Micro- Textures on the Performance of Hydrodynamic Journal Bearing Juan Esteban Arango Amaya Instituto Tecnológico Metropolitano – ITM Medellín 1

General information Anil Shindea, Prashant Pawarb, Sunil Gaikwadc, Ranjit Kapurkard, Avinash Parkhee Materials today: proceedings

Research problem How to improve the journal bearing performance through micro-textured surfaces? 3 Fig 2. Texturization trought grooves [2].[2] Fig 1. Texturization trought dimples [1].[1]

Problem’s background Hamilton et al. and Qiu YY et al. found that the surface micro-textures have considerable influence on wear resistance, frictional power loss and load carrying capacity of the journal bearings [3-4].[3-4] Satish et al. showed that values of load carrying capacity, maximum pressure and frictional power losses are significantly affected with textured surfaces [5].[5] Nacer studied the effect of different micro-textures and observed that the cylindrical shape micro- texture and its location improve the performance of hydrodynamic journal bearing [6].[6] Ashwin et al. investigated friction characteristics of micro-textured surfaces throught Navier-Stokes model to predict textured induced lift and concluded that textured surfaces exhibit friction as much as 80% lower than smooth surfaces [7].[7] 4

Methodology: model Fig 3. Model [Author]. (e) Eccentricity. (ε) The eccentricity ratio (c) Clearance (Rj) Journal radius (Dj) Journal diameter (Db) Bearing diameter (L) Journal and bearing Length (μ) Oil viscosity 5

Methodology: numerical system Fig 4. Governing equations [Author]. (P) Fluid film pressure (h) Fluid film thickness (θ) Angular position ∆h(θ,Z) Fluid film thickness due to surface micro-textures 6

Methodology: model properties 7 Source: Author

Methodology: micro-textures for surfaces Fig 5. Micro-textures on the journal [Author].Fig 6. Details of the micro-textures [Author]. 8

Results and discussion 9 Source: Author

Results and discussion 10 Fig 7. Numerical analysis of smooth surface journal bearing [Author].

Results and discussion Fig 8. Numerical results of journal bearing with rectangular groove [Author]. 11

Results and discussion 12 Fig 9. Effect of journal speed on fluid film pressure development [Author].

Results and discussion 13 Fig 10. Effect of journal speed on frictional power loss [Author].

Conclusions It can be conclude that the journal bearing with rectangular rib micro-textures have maximum film pressure development and frictional power loss as compared with journal bearing with different surface micro-textures vs the smooth surface. it can also be conclude that journal bearing with rectangular micro-texture groove, have minimum film pressure development and frictional power loss as compared with other deterministic micro-textures vs the smooth surface.

References [1] P. Sugar, J. Sugarova, and M. Frncik, “Laser surface texturing of tool steel: textured surfaces quality evaluation,” Open Eng., vol. 6, no. 1, pp. 90–97, [2] Q. Bao, M. M. Khonsari, K. Li, H. Zhao, and Q. Lin, “An investigation into the transient behavior of journal bearing with surface texture based on fluid-structure interaction approach,” Tribol. Int., vol. 118, no. July 2017, pp. 246–255, [3] Hamilton DB, Walowit JA, Allen CM. A Theory of Lubrication by Microirregularities. ASME. J. Basic Eng. 1966;88(1): doi: / [4] Qiu YY, Khonsari MM. Performance Analysis of Full-Film Textured Surfaces With Consideration of Roughness Effects. ASME. J. Tribol. 2011;133(2): doi: / [5] Satish C. Sharma, Saurabh K. Yadav. Performance analysis of a fully textured hybrid circular thrust pad bearing system operating with nonNewtonian lubricant. Tribology International 77:2014; [6] Nacer Tala-Ighil, Mical Fillon, Patrick Maspeyrot. Effect of textured area on the performance of hydrodynamic journal bearing. Tribology International 44:2011; [7] Ashwin Ramesh, Wasim Akram, Surya P. Mishra, Andrew H. Cannon, Andreas A. Polycarpou, William P. King. Friction characteristics of microtextured surfaces under mixed and hydrodynamic lubrication. Tribology International 57 (2013) 170–176.

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