# Numerical Study of Power Loss and Lubrication of Connecting Rod Big-End

^{*}

## Abstract

**:**

## 1. Introduction

## 2. Model and Procedure

- Lubricant is assumed to be Newtonian and incompressible, therefore oil density remains unchanged;
- Lubricant is treated as an iso-viscous fluid;
- Oil flow is assumed laminar;
- Hydrodynamic lubrication has been considered at connecting rod big-end and crankpin interface;
- There is no slippage at the boundaries;
- Elastic deformation of bearing surfaces has been neglected.

#### 2.1. Connecting Rod Big-End Loads

#### 2.2. Reynolds Equation for Bearing Analysis

#### 2.3. Numerical Solution

## 3. Model Validation

## 4. Results and Discussion

## 5. Conclusions

## Author Contributions

## Funding

## Acknowledgments

## Conflicts of Interest

## Appendix A. Hydrodynamic Force Components, F^{r} and F^{t} Based on Mobility Method for π Film Lubricated Journal Bearing

## References

- Rahnejat, H. (Ed.) Tribology and Dynamics of Engine and Powertrain: Fundamentals, Applications and Future Trends; Woodhead Publishing: Cambridge, UK, 2010. [Google Scholar]
- Stachowiak, G.; Batchelor, A.W. Engineering Tribology; Butterworth-Heinemann: Oxford, UK, 2013. [Google Scholar]
- Khonsari, M.M.; Booser, E.R. Applied Tribology: Bearing Design and Lubrication; John Wiley and Sons: New York, NY, USA, 2017. [Google Scholar]
- Delprete, C.; Razavykia, A. Piston dynamics, lubrication and tribological performance evaluation: A review. J. Eng. Res.
**2018**. [Google Scholar] [CrossRef] - Delprete, C.; Razavykia, A. Piston ring–liner lubrication and tribological performance evaluation: A review. J. Eng. Tribol.
**2018**, 232, 193–209. [Google Scholar] [CrossRef] - Booker, J.F. Dynamically loaded journal bearings: Mobility method of solution. J. Basic Eng.
**1965**, 87, 537–546. [Google Scholar] [CrossRef] - Booker, J.F. Dynamically-loaded journal bearings: Numerical application of the mobility method. J. Lubr. Technol.
**1971**, 93, 168–174. [Google Scholar] [CrossRef] - Goenka, P.K. Analytical curve fits for solution parameters of dynamically loaded journal bearings. J. Tribol.
**1984**, 106, 421–427. [Google Scholar] [CrossRef] - Fantino, B.; Godet, M.; Frêne, J. Dynamic Behaviour of an Elastic Connecting—Rod Bearing—Theoretical Study; SAE Technical Paper; SAE International: Warrendale, PA, USA, 1983; Volume 830307. [Google Scholar]
- Fantino, B.; Frene, J. Comparison of dynamic behavior of elastic connecting-rod bearing in both petrol and diesel engines. J. Tribol.
**1985**, 107, 87–91. [Google Scholar] [CrossRef] - Hirani, H.; Athre, K.; Biswas, S. Dynamically loaded finite length journal bearings: Analytical method of solution. J. Tribol.
**1999**, 121, 844–852. [Google Scholar] [CrossRef] - Paranjpe, R.S. Analysis of non-Newtonian effects in dynamically loaded finite journal bearings including mass conserving cavitation. J. Tribol.
**1992**, 114, 736–744. [Google Scholar] [CrossRef] - Livanos, G.; Kyrtatos, N.P. A Model of the Friction Losses in Diesel Engines; SAE Technical Paper; 2006-01-0888; SAE International: Warrendale, PA, USA, 2006. [Google Scholar]
- DuBois, G.B.; Ocvirk, F.W. Analytical Derivation and Experimental Evaluation of Short-bearing Approximation for Full Journal Bearing; NACA Report; NACA: Boston, MA, USA, 1953; Volume 1157. [Google Scholar]
- Vignolo, G.G.; Barilá, D.O.; Quinzani, L.M. Approximate analytical solution to Reynolds equation for finite length journal bearings. Tribol. Int.
**2011**, 44, 1089–1099. [Google Scholar] [CrossRef] - Chasalevris, A.; Sfyris, D. Evaluation of the finite journal bearing characteristics, using the exact analytical solution of the Reynolds equation. Tribol. Int.
**2013**, 57, 216–234. [Google Scholar] [CrossRef] - Abbasi, A.; Khadem, S.E.; Bab, S.; Friswell, M.I. Vibration control of a rotor supported by journal bearings and an asymmetric high-static low-dynamic stiffness suspension. Nonlinear Dyn.
**2016**, 85, 525–545. [Google Scholar] [CrossRef] - Dousti, S.; Allaire, P.; Dimond, T.; Cao, J. An extended Reynold equation applicable to high reduced Reynolds number operation of journal bearings. Tribol. Int.
**2016**, 102, 182–197. [Google Scholar] [CrossRef] - Booker, J.F. Basic equations for fluid films with variable properties. J. Tribol.
**1989**, 111, 475–479. [Google Scholar] [CrossRef] - Martin, F.A. Friction in Internal Combustion Engine Bearings. Proc. Inst. Mech. Eng.
**1985**, C67/85, 1–17. [Google Scholar] - Booker, J.F. A Table of the Journal-Bearing Integral. J. Basic Eng.
**1965**, 87, 533–535. [Google Scholar] [CrossRef]

**Figure 5.**Hydrodynamic pressure at crankpin journal/connecting rod big-end interface (engine spin speed $\omega =2000$ rpm).

**Figure 8.**Power loss at connecting rod big-end calculated by proposed model and Mobility method under motored and fired conditions.

**Figure 10.**Effect of temperature on power loss under fired condition, calculated by Mobility method and model.

c | journal-bearing clearance (mm) | 0.026 |

D | cylinder bore (mm) | 83.80 |

l | connecting rod length (mm) | 153 |

${L}_{x}$ | journal width (mm) | 19.5 |

r | crank radius (mm) | 49.5 |

${R}_{j}$ | crankpin radius (mm) | 25.45 |

${m}_{pis}$ | piston mass (kg) | 0.540 |

${m}_{pin}$ | wrist pin mass (kg) | 0.257 |

${m}_{cr}$ | connecting rod mass (kg) | 0.714 |

${z}_{owp}$ | wrist pin offset (mm) | 0.5 |

${z}_{oc}$ | crankshaft offset (mm) | 0 |

$\eta $ | oil dynamic viscosity (mPa·s) | 11.734 |

$\sigma $ | combined surface roughness ($\mathsf{\mu}$m) | 0.37 |

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

## Share and Cite

**MDPI and ACS Style**

Razavykia, A.; Delprete, C.; Baldissera, P. Numerical Study of Power Loss and Lubrication of Connecting Rod Big-End. *Lubricants* **2019**, *7*, 47.
https://doi.org/10.3390/lubricants7060047

**AMA Style**

Razavykia A, Delprete C, Baldissera P. Numerical Study of Power Loss and Lubrication of Connecting Rod Big-End. *Lubricants*. 2019; 7(6):47.
https://doi.org/10.3390/lubricants7060047

**Chicago/Turabian Style**

Razavykia, Abbas, Cristiana Delprete, and Paolo Baldissera. 2019. "Numerical Study of Power Loss and Lubrication of Connecting Rod Big-End" *Lubricants* 7, no. 6: 47.
https://doi.org/10.3390/lubricants7060047