表面织构对水润滑径向滑动轴承湍流特性的影响

Effects of Surface Texture on Turbulent Lubrication of Water-lubricated Journal Bearing

基于湍流理论,采用RNG k-ε湍流模型,研究水润滑径向滑动轴承轴瓦表面加工织构凹坑对轴承水膜压力、承载能力和湍流特性的影响,比较织构形状、分布位置、多尺度以及尺寸参数对轴承润滑性能的影响。结果表明:复杂形状织构加剧了水膜的湍流流动,导致更大的湍流动能,提高了水膜压力和承载力;织构棱边、尖角越多,越易形成二次涡;轴承收敛楔形入口处织构降低轴承承载能力,出口处织构提高承载力,且越靠近出口提升效果越明显;织构轴向尺寸与周向尺寸之比对轴承承载能力影响明显,并且存在最佳比值。

A method based on turbulence theory was used to study the lubrication of the journal bearing with surface texture.The influences of the surface texture, applied in the bearing.pad of water-lubricated journal bearing, on the water film pressure,load capacity and turbulent characteristics were studied based on the turbulent model, RNG k-ε model, and the effects of shape, location, multi-scale and size of surface textures on the turbulent lubrication characteristics of bearing were analyzed.The results show that complicated surface texture enhances the turbulent flow of water film and the turbulent kinetic energy, and improves the pressure and carrying capacity of water film.The more edges and sharp corners the texture contains ,the easier it forms the secondary vortex.The texture in the entrance zone of wedge-shape reduces load capacity, however that in the exit zone improves load capacity, and the closer to the exit ,the stronger this effect.The load capacity of the bearings can be significantly affected by the ratio of the texture axial dimension to its circumferential dimension, and there exists the best ratio value.