Print Email Facebook Twitter Global Robust Optimization of Computationally Expensive Systems Title Global Robust Optimization of Computationally Expensive Systems: A Lavel Rotor Suspended by Fluid Film Bearings Author Immerzeel, F.C. Contributor van Ostayen, R.A.J. (mentor) Langelaar, M. (mentor) Eling, R.P.T. (mentor) Faculty Mechanical, Maritime and Materials Engineering Department Precision and Microsystems Engineering (PME) Programme Engineering Mechanics Date 2016-08-16 Abstract Kriging based methods enable the deterministic and robust optimization of computationally expensive systems. With a limited amount of function evaluations the optima are found in an iterative process with expected improvement as infill sampling criteria. Outputs of computer models can be stochastic and/or the models do not always succeed to perform the analysis. For the latter case, a problem is said to be affect by a hidden constraint. Regression Kriging can be included in the methods to deal with the stochastic model outputs. A new method is introduced to handle the hidden constraint in both deterministic and robust optimization. The methods are used to optimize a validated model of a Laval rotor suspended by plain journal bearings. To capture the non-linear behaviour of the self-excited vibrations, a computationally expensive time-transient run-up analysis needs to be performed. The output of this model is stochastic and the model fails to perform a run-up for some combinations of model inputs. The most influential control variables and uncertainties are indicated with an efficient global sensitivity study and used to optimize the system. With the extension of the deterministic and robust optimization, the optima are successfully obtained and can be compared. Subject robust optimizationefficient global optimizationmetamodelKriginghidden constraintLaval rotorhydrodynamic bearingwhirlwhip To reference this document use: http://resolver.tudelft.nl/uuid:e2c73349-91f6-4db7-9f24-cd90f4cbf167 Part of collection Student theses Document type master thesis Rights (c) 2016 Immerzeel, F.C. Files PDF Thesis_FC_Immerzeel_20160805.pdf 32.24 MB Close viewer /islandora/object/uuid:e2c73349-91f6-4db7-9f24-cd90f4cbf167/datastream/OBJ/view