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

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## 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

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**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 |

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**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