Experimental Research about the Effect of Carbon Black Particles on Noise in Oscillatory Parallel Plate Squeeze Oil Film

Abstract

To reduce the irregular “typewriter” noise in main engine bearings, a comprehensive experimental study on the effect of carbon black particles (CBPs) with different particle sizes, concentrations, and standing times on noise in an oscillatory parallel-plate oil squeeze film test apparatus was carried out. The results show that the presence of CBPs can significantly reduce the generation of noise. In addition, as the concentration increases, this suppression effect becomes stronger at low concentrations and tends to be stable at high concentrations. Moreover, CBPs with a smaller particle size have better noise suppression effects that persist after standing same time when compared with CBPs with a larger particle size. To determine the mechanism of CBPs’ noise suppression ability, the change in cavitation area, volume, and volume change rate in the period of noise occurrence was obtained by combining image processing and displacement sensor data. The results show that the level of cavitation noise is positively related to the volume change rate during cavitation collapse. The noise suppression effect of CBPs is due to the role that CBPs play as cavitation nuclei in lubricating oil, dispersing cavitation and accelerating the formation and collapse of the cavitation area, thus reducing the chance of connecting with the atmosphere in the process of cavitation collapse.

Keywords:

• Fluid lubrication
• cavitation
• noise
• carbon black particles

Acknowledgement

The authors gratefully acknowledge D. C. Sun, retired professor of State University of New York at Binghamton, for his encouragement and suggestions.

Additional information

Funding

The authors are grateful for support from Ford Motor Company under Ford University Project 2014-2175R.