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	2014-03-01T02:52:40Z
dc.date.available	2014-03-01T02:52:40Z
dc.date.issued	2010	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/35987
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-82055195390&partnerID=40&md5=a251ee947b52c4755131d60f4526ac11	en
dc.subject	Micro-bearings	en
dc.subject	Navier-Stokes equations	en
dc.subject	Optimization	en
dc.subject	Trapezoidal texturing	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	Local search method	en
dc.subject.other	Micro thrust	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	Air	en
dc.subject.other	Computational fluid dynamics	en
dc.subject.other	Convergence of numerical methods	en
dc.subject.other	Geometry	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	Turbines	en
dc.subject.other	Viscous flow	en
dc.subject.other	Thrust bearings	en
dc.title	Evolutionary optimization of micro-thrust bearings with periodic partial trapezoidal surface texturing	en
heal.type	conferenceItem	en
heal.publicationDate	2010	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 microchannels, 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, substantial increase in the 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. © 2010 by ASME.	en
heal.journalName	Proceedings of the ASME Turbo Expo	en
dc.identifier.volume	5	en
dc.identifier.spage	339	en
dc.identifier.epage	348	en