Effect of distributed piezoelectric segments on the buckling load of FG cylindrical micro/nano shell

Heidari, Yaser; Arefi, Mohammad; Rahaghi, Mohsen Irani

doi:10.1140/epjp/s13360-020-01055-7

Cited by 9 publications

(1 citation statement)

References 71 publications

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“…It is found that the presence of cracks weakened oil film forces of the bearing-rotor system at high speeds, the clearance ratio had a greater effect on internal and external oil film vorticity, and the rotor operating stability can be improved by increasing the impeller eccentricity. Irani-Rahaghi et al 42 and Heidari et al [43][44][45][46] studied free vibration of functionally sandwich cylindrical shells integrated with a piezoelectric layer.…”

Section: Introductionmentioning

confidence: 99%

Vibration characteristics of turbocharger rotor system considering internal thread texture parameters of semi-floating ring bearing

Zhong

Jiang

Bin

et al. 2023

Proceedings of the Institution of Mechanical Engineers, Part J:

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The internal thread texture causes changes in the dynamic characteristics of the oil film of the semi-floating ring bearing, which affects the amplitude of vibration and operating life of the turbocharger rotor system. Based on the fluid lubrication theory, the oil film governing equation of a semi-floating ring bearing with surface texture parameters is derived. The effects of the texture depth, position, and number of turns of the internal thread on the dynamic characteristics of the bearing oil film, such as the maximum pressure, load-carrying capacity and stiffness damping, are analyzed. Taking a type of turbocharger as an example, a hydrodynamic model is established to analyze the oil film lubrication in the semi-floating ring bearings, and the dynamic characteristic of the oil film is analyzed by computational fluid dynamics method. The results show that the maximum pressure, bearing capacity, and stiffness damping coefficient of oil film increase firstly and then decrease with the increase of texture depth and the number of thread turns in the range of journal rotation speed from 1000 to 20,0000 r/min. Compared with the non-texture bearings, the dynamic characteristics coefficients of the oil film such as bearing capacity and stiffness damping increase the most, when the depth of texture is 0.006 mm and the number of thread turns is 9. Secondly, the dynamic characteristic coefficient of oil film is improved when the texture is distributed in the middle than on both sides. The thread texture with appropriate parameters can suppress the rotor system vibration amplitude. The conclusion can provide a reference for the design of textual parameters of semi-floating ring bearings.

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Section: Introductionmentioning

confidence: 99%