## 4 Results and Discussion
It is clear from Figure 9 that relocating surface textures from the main high-pressure zone to adjacent 300-330\({}^{\circ}\) regions triggers significant pressure redistribution where moderate pressure elevation occurs in the upper lobe's entry section alongside substantial pressure reduction in the lower lobe's principal load-bearing zones, ultimately reversing traditional pressure gradient behavior. Given the dominant influence of pressure distribution on both static and dynamic performance metrics of the bearing, strategic texturing of the lower lobe's high-pressure sector (270-300\({}^{\circ}\)) emerges as the most impactful approach for modifying the operational behavior of the evaluated two-lobe bearing systems. Figure 9: Effect of depth and geometric shape of surface textures on the thickness of the lubricating fluid film and distributed pressure in a noncircular two-lobe journal bearing; **(a)** smooth surface; **(b)** cubic texture; **(c)** cylindrical texture; **(d)** semi-ellipsoidal texture. Figure 10 illustrates how varying depth magnitudes of engineered surface features (cubic, cylindrical, and semi-ellipsoidal geometries) patterned across the 270\({}^{\circ}\leq\theta_{tex}\leq 300^{\circ}\) and 300\({}^{\circ}\leq\theta_{tex}\leq 330^{\circ}\) sectors of the bearing's interior surface influence hydrodynamic pressure development along the bearing's axial centerline. The findings reveal that texturing the high-pressure zone corresponding to 270-300\({}^{\circ}\) circumferential angles enhances pressure distribution within the lower bearing lobe, albeit with marginal pressure reduction in the upper lobe. As evidenced by the data plots, surface patterning in this high-load region elevates central longitudinal plane pressures beyond maximum values observed in plain bearings at specific locations. Conversely, texture application in low-pressure zones (300-330\({}^{\circ}\) range) predominantly induces pressure decline across lower load-bearing lobe areas, while paradoxically increasing pressures at select upper lobe points above comparable plain bearing values. This behavioral trend stems from corresponding enhancements in fluid film thickness resulting from deeper surface modifications along the bearing's interior wall. Figure 10: Effect of depth and geometric shape of surface textures on the lubricant oil film pressure in the central plane of the bearing’s longitudinal direction: (**a**) cubic texture; (**b**) cylindrical texture; (**c**) semi-ellipsoidal texture. The plotted data demonstrate a progressive attenuation of pressure enhancement in the bearing's lower lobe relative to plain bearings as texture depth increases within the 270-300\({}^{\circ}\) angular sector. Conversely, surface modifications in the 300-330\({}^{\circ}\) region initially generate substantial pressure reduction in the lower lobe, with pressure variation magnitudes becoming constrained beyond geometry-specific critical depth thresholds. The results of Figure 10 fundamentally indicate the existence of an optimal depth for each type of investigated textures to maximize bearing performance enhancement. Exceeding this critical depth yields diminishing returns and, in certain cases, performance deterioration. Cubic textures exhibit the shallowest optimal depth, while cylindrical and semi-ellipsoidal configurations require progressively greater depths for peak effectiveness. The analysis reveals minimal pressure variation across most texture depths on the primary lobe surface, with more pronounced reductions observed when texturing the 270-300\({}^{\circ}\) circumferential segment. This behavior results from the upper lobe's auxiliary load-bearing function in two-lobe journal bearings, where the lower lobe maintains primary pressure absorption. Consequently, all critical performance metrics in such bearing systems are predominantly determined by the lower lobe's pressure-dependent characteristics.