ACTA AERONAUTICAET ASTRONAUTICA SINICA >
Flow Characteristics Analysis of Wall Oil Film with Consideration of Oil Droplet Deformation and Secondary Oil Droplet Deposition in Aeroengine Bearing Chamber
Received date: 2012-10-22
Revised date: 2013-01-29
Online published: 2013-02-01
Supported by
National Natural Science Foundation of China(50975233,51275411)
The thickness and velocity profiles of a wall oil film under air/oil two-phase flow conditions in an aeroengine bearing chamber have a strong and direct influence on the performance of lubrication and heat transfer of the chamber. This paper takes into consideration the deformation of primary oil droplets and the deposition of secondary oil droplets, and then determines the mass and momentum transfers in the process of deposition of oil droplets. The analysis contains droplet deformation and motion, mass and momentum transferred to the wall film with impingement of droplets/wall, and motion and deposition of secondary oil droplets. Based on the knowledge so obtained, the wall film thickness and velocity are subsequently calculated using a film flow model established by force balance and mass conservation. The effect of deformation on droplet velocity and trajectory is analyzed, and the effects of deformation and secondary droplet deposition on mass and momentum transfers and wall film thickness and velocity are discussed. The calculation results show preliminarily that droplet velocities decrease and trajectories become more bent due to the effect of deformation. When taking no account of secondary oil droplet deposition, the mass transfer of deformation droplets increases and the momentum transfer decreases in relation to those of spherical droplets. The number of secondary oil droplets is much larger, and the total mass and momentum transfers are mainly obtained from the secondary deposition. Film thickness and velocity increase significantly due to the influence of droplet deformation and secondary deposition, and lubrication oil is accelerated to exit the chamber through the seavenge port.
CHEN Bo , CHEN Guoding , WANG Tao . Flow Characteristics Analysis of Wall Oil Film with Consideration of Oil Droplet Deformation and Secondary Oil Droplet Deposition in Aeroengine Bearing Chamber[J]. ACTA AERONAUTICAET ASTRONAUTICA SINICA, 2013 , 34(8) : 1980 -1989 . DOI: 10.7527/S1000-6893.2013.0119
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