Evolutionary optimization of micro-thrust bearings with periodic partial trapezoidal surface texturing

Papadopoulos, CI; Nikolakopoulos, PG; Kaiktsis, L

dc.contributor.author	Papadopoulos, CI	en
dc.contributor.author	Nikolakopoulos, PG	en
dc.contributor.author	Kaiktsis, L	en
dc.date.accessioned	2014-03-01T01:35:39Z
dc.date.available	2014-03-01T01:35:39Z
dc.date.issued	2011	en
dc.identifier.issn	0742-4795	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/21150
dc.subject	micro-bearings	en
dc.subject	Navier-Stokes equations	en
dc.subject	optimization	en
dc.subject	trapezoidal texturing	en
dc.subject.classification	Engineering, Mechanical	en
dc.subject.other	Bearing performance	en
dc.subject.other	CFD codes	en
dc.subject.other	Convergence ratio	en
dc.subject.other	Design variables	en
dc.subject.other	Evolutionary optimizations	en
dc.subject.other	Isothermal flows	en
dc.subject.other	Load carrying capacities	en
dc.subject.other	Local search method	en
dc.subject.other	Micro-bearings	en
dc.subject.other	Numerical solution	en
dc.subject.other	Objective functions	en
dc.subject.other	Optimization problems	en
dc.subject.other	Optimization studies	en
dc.subject.other	Optimization tools	en
dc.subject.other	Performance improvements	en
dc.subject.other	Surface-texturing	en
dc.subject.other	trapezoidal texturing	en
dc.subject.other	Bearings (structural)	en
dc.subject.other	Computational fluid dynamics	en
dc.subject.other	Computational geometry	en
dc.subject.other	Convergence of numerical methods	en
dc.subject.other	Load limits	en
dc.subject.other	Navier Stokes equations	en
dc.subject.other	Optimization	en
dc.subject.other	Stators	en
dc.subject.other	Viscous flow	en
dc.subject.other	Walls (structural partitions)	en
dc.subject.other	Thrust bearings	en
dc.title	Evolutionary optimization of micro-thrust bearings with periodic partial trapezoidal surface texturing	en
heal.type	journalArticle	en
heal.identifier.primary	10.1115/1.4001990	en
heal.identifier.secondary	http://dx.doi.org/10.1115/1.4001990	en
heal.identifier.secondary	012301	en
heal.language	English	en
heal.publicationDate	2011	en
heal.abstract	An optimization study of trapezoidal surface texturing in slider micro-bearings, via computational fluid dynamics (CFD), is presented. The bearings are modeled as micro-channels, consisting of a moving and a stationary wall. The moving wall (rotor) is assumed smooth, while part of the stationary wall (stator) exhibits periodic dimples of trapezoidal form. The extent of the textured part of the stator and the dimple geometry are defined parametrically; thus, a wide range of texturing configurations is considered. Flow simulations are based on the numerical solution of the Navier-Stokes equations for incompressible isothermal flow. To optimize the bearing performance, an optimization problem is formulated and solved by coupling the CFD code with an optimization tool based on genetic algorithms and local search methods. Here, the design variables define the bearing geometry, while load carrying capacity is the objective function to be maximized. Optimized texturing geometries are obtained for the case of parallel bearings for several numbers of dimples, illustrating significant load carrying capacity levels. Further, these optimized texturing patterns are applied to converging bearings for different convergence ratio values; the results demonstrate that, for small and moderate convergence ratios, a substantial increase in load carrying capacity, in comparison to smooth bearings, is obtained. Finally, an optimization study performed at a high convergence ratio shows that, in comparison to the parallel slider, the optimal texturing geometry is substantially different, and that performance improvement over smooth bearings is possible even for steep sliders. [DOI: 10.1115/1.4001990]	en
heal.publisher	ASME-AMER SOC MECHANICAL ENG	en
heal.journalName	Journal of Engineering for Gas Turbines and Power	en
dc.identifier.doi	10.1115/1.4001990	en
dc.identifier.isi	ISI:000282274800015	en
dc.identifier.volume	133	en
dc.identifier.issue	1	en