Classifying, Predicting, and Reducing Strategies of the Mesh Excitations of Gear Whine Noise: A Survey

Table 4

Formula of the friction force coefficient.

Formulae	Model type	Reference
	Coulomb	[176–184, 187–190, 192, 193, 199, 205–210]
	Empirical	[191, 195]
	Mix lubricant condition (experimentally)	[174, 196]
	EHL	[185, 200, 201, 211, 212]
	Mixed EHL condition (analytically)	[203]
	(ISO)	[213]

The definition and value of each coefficient in the formula can be found in the corresponding reference.