Homogenization of Reynolds equations
2007 (English)Licentiate thesis, comprehensive summary (Other academic)
This Licentiate thesis is focussed on some new questions in homogenization theory, which have been motivated by some concrete problems in tribology. From the mathematical point of view, these questions are equipped with scales of Reynolds equations with rapidly oscillating coefficients. In particular, in this Licentiate thesis we derive the corresponding homogenized (averaged) equation. We consider the Reynolds equations in both the stationary and unstationary forms to analyze the effect of surface roughness on the hydrodynamic performance of bearings when a lubricant is flowing through it. In Chapter 1 we describe the possible types of surfaces a bearing can take. Out of these, we select two types and derive the appropriate Reynolds equations needed for their analysis. Chapter 2 is devoted to the derivation of the homogenized equations, associated with the stationary forms of the compressible and incompressible Reynolds equations. We derive these homogenized equations by using the multiple scales expansion technique. In Chapter 3 the homogenized equations for the unstationary forms of the Reynolds equations are considered and some numerical results based on the homogenized equations are presented. In chapter 4 we consider the equivalent minimization problem for the unstationary Reynolds equation and use it to derive a homogenized minimization problem. Finally, we obtain both the lower and upper bounds for the derived homogenized problem.
Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2007. , 72 p.
Licentiate thesis / Luleå University of Technology, ISSN 1402-1757 ; 2007:30
Research subject Mathematics
IdentifiersURN: urn:nbn:se:ltu:diva-17451Local ID: 370e2280-0927-11dc-9854-000ea68e967bOAI: oai:DiVA.org:ltu-17451DiVA: diva2:990456
Godkänd; 2007; 20070523 (ysko)2016-09-292016-09-29Bibliographically approved