## 4 Analysis of Bearing Lubrication Characteristics under Cavitation Effect  
Analysis of Lubrication Characteristics of Divergent Wedge Slider Bearing Based on Full Texture Model  
In the analysis of a convergent wedge texture model, CFD calculation can be completed only by using a pressure-based solver. For the divergent wedge texture model, the influence of cavitation should be considered. Figure 12 shows the distribution of oil film pressure on the moving wall before and after considering the cavitation effect when the streamwise dimensionless texture depth is 0.5. The abscissa \(-\)5 mm point in the figure corresponds to the oil film inlet, and +5 mm corresponds to the oil film outlet. The figure on the left shows the situation without considering the cavitation effect. The oil film pressure distribution is similar to a parabola. When the \(x\)-axis coordinate is about \(-\)1 mm, there is a minimum pressure of \(-\)0.9 MPa (absolute pressure); the picture on the right shows the case considering the cavitation effect. On the moving wall, the oil film pressure in the middle of the wall is equal to the cavitation pressure. There is a sudden change in the pressure value at the inlet and outlet of the oil film, and the oil film pressure at the inlet. The strength first increases to 0.038 MPa and then decreases to the cavitation pressure, while the oil film pressure at the outlet surges from the cavitation pressure to about 0.082 MPa. The upper part of the left figure shows the pressure position of cavitation pressure, showing the huge difference between considering and not considering cavitation. According to the previous analysis, the arrangement of the micro-texture at the inlet will lead to the reduction of LCC, while at the outlet, due to the consideration of cavitation effect, the negative pressure strength obtained without considering cavitation effect is corrected, which improves the LCC. Therefore, it can be imagined that if the cavitation effect is strengthened by using a micro-texture at the exit, the LCC may be improved. Figure 13 shows the corresponding dimensionless bearing capacities from the analysis of different dimensionless texture depths for a fully textured diverging wedge slider bearing. Figure 11: Influence of local texture on oil film pressure distribution. Figure 13 shows that changing the depth of the texture has no obvious effect on improving the LCC, but it usually does not reduce the LCC. Figure 14 shows the dimensionless shear force obtained by changing the dimensionless texture depth analysis. Figure 14: The effect of the depth of streamwise texture on the dimensionless shear force. Figure 12: Pressure distribution on moving wall before and after considering cavitation effect in streamwise texture. Figure 13: The influence of the depth of streamwise texture on the dimensionless LCC. It can be seen from Figure 14 that increasing the texture depth is very effective in reducing the wall shear force, and its maximum drag reduction rate is likely to reach 22%. In order to compare the two different directions of micro texture used in the previous convergent wedge, the oil film pressure analysis, dimensionless LCC and dimensionless shear force analysis of the divergent wedge with a transverse micro-texture are carried out. The characteristics of oil film pressure are almost the same as those in the streamwise micro-texture pressure distribution in Figure 12, but the LCC and shear force are quite different. Figure 15 shows the dimensionless LCC obtained by changing the dimensionless texture depth analysis. Figure 15 shows that the LCC of the transverse texture model is greater than that of the smooth model. The dimensionless LCC first increases rapidly with increasing dimensionless texture depth, and when the dimensionless texture depth is 0.6, the maximum dimensionless LCC is 1.18, and then the dimensionless LCC decreases slowly.