Jet cooling characteristics for ball bearings using the VOF multiphase model

In a jet cooling ball bearing, the oil is mixed with the air and air-oil two-phase flow field is formed. The flow behaviours and heat transfer characteristics of the two-phase flow are significant for cooling evaluation and temperature control of the bearing. This paper investigates the fluid flow and heat transfer characteristics of a jet cooling ball bearing. The air-oil distribution and temperature distribution inside the ball bearing are calculated. The results indicate that micro bubbles are mixed into the oil at high-speed operation conditions. The highest oil volume fraction position is close to the nozzle and moves along the rotation direction at different speeds. Considering the air-oil two-phase distribution, the heat transfer simulation model using the VOF method is well enough for the present analysis. There is a correlation between the temperature distribution and the air-oil distribution inside the bearing. The lower temperature always appears at the higher oil volume fraction position. Optimizing the cooling mechanism according to the oil volume fraction distribution is helpful to achieve greater cooling effect.