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Optimization of fir-tree-type turbine blade roots using photoelasticity

Thesis (MEng.) -- University of Stellenbosch, 1992.

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Main Author: Hettasch, Georg
Other Authors: Endres, W.
Format: Thesis
Language:English
Published: Stellenbosch : University of Stellenbosch 2010
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access_status_str Open Access
author Hettasch, Georg
author2 Endres, W.
author_browse Endres, W.
Hettasch, Georg
author_facet Endres, W.
Hettasch, Georg
author_sort Hettasch, Georg
collection Thesis
dc_rights_str_mv University of Stellenbosch
description Thesis (MEng.) -- University of Stellenbosch, 1992.
format Thesis
id oai:scholar.sun.ac.za:10019.1/993
institution Stellenbosch University (South Africa)
language English
last_indexed 2026-06-10T12:47:10.728Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository
publishDate 2010
publishDateRange 2010
publishDateSort 2010
publisher Stellenbosch : University of Stellenbosch
publisherStr Stellenbosch : University of Stellenbosch
record_format dspace
source_str SUNScholar — Stellenbosch University Repository
spelling oai:scholar.sun.ac.za:10019.1/993 Optimization of fir-tree-type turbine blade roots using photoelasticity Hettasch, Georg Endres, W. Wettstein, H. University of Stellenbosch. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering. Dissertations -- Mechanical engineering Turbo-machinery Blade root geometries Turbomachines -- Blades Blades -- Mathematical models Photoelasticity Thesis (MEng.) -- University of Stellenbosch, 1992. ENGLISH ABSTRACT: The large variety of turbo-machinery blade root geometries in use in industry prompted the question if a optimum geometry could be found. An optimum blade root was defined as a root with a practical geometry which, when loaded, returns the minimum fillet stress concentration factor. A literature survey on the subject provided guidelines but very little real data to work from. An initial optimization was carried out using a formula developed by Heywood to determine loaded projection fillet stresses. The method was found to produce unsatisfactory results, prompting a photoelastic investigation. This experimental optimization was conducted in two stages. A single tang defined load stage and a single tang in-rotor stage which modeled the practical situation. The defined load stage was undertaken in three phases. The first phase was a preliminary investigation, the second phase was a parameter optimization and the third phase was a geometric optimization based on a material utilization optimization. This material optimization approach produced good results. From these experiments a practical optimum geometry was defined. A mathematical model which predicts the fillet stress concentration factor for a given root geometry is presented. The effect of expanding the single tang optimum to a three tang root was examined. AFRIKAANSE OPSOMMING: Die groot verskeidenheid lemwortelgeometrieë wat in turbomasjiene gebruik word het die vraag na 'n optimum geometrie laat ontstaan. Vir hierdie ondersoek is 'n optimum geometrie gedefineer as 'n praktiese geometrie wat, as dit belas word, die mimimum vloeistukspanningskonsentrasiefaktor laat ontstaan. 'n Literatuur studie het riglyne aan die navorsing gegee maar het wynig spesifieke en bruikbare data opgelewer. Die eerste optimering is met die Heywood formule, wat vloeistukspannings in belaste projeksies bepaal, aangepak. Die metode het nie bevredigende resultate opgelewer nie. 'n Fotoelastiese ondersoek het die basis vir verdere optimeering gevorm. Hierdie eksperimentele optimering is in twee stappe onderneem. 'n Enkelhaak gedefineerde lasgedeelte en 'n enkelhaak in-rotor gedeelte het die praktiese situasie gemodeleer. Die gedefineerde lasgedeelte is in drie fases opgedeel. Die eerste fase was n voorlopige ondersoek. Die tweede fase was 'n parameter optimering. 'n Geometrie optimering gebasseer op 'n materiaal benuttings minimering het die derde fase uitgemaak. Die materiaal optimerings benadering het goeie resultate opgelewer. Vanuit hierdie eksperimente is 'n optimum praktiese geometrie bepaal. 'n Wiskundige model is ontwikkel, wat die vloeistukspanningskonsentrasiefaktor vir 'n gegewe wortelgeometrie voorspel. Die resultaat van 'n geometriese uitbreiding van die enkelhaaklemwortel na 'n driehaaklemwortel op die spanningsverdeling is ondersoek. 2010-05-25T07:15:37Z 2010-05-25T07:15:37Z 1992-12 Thesis http://hdl.handle.net/10019.1/993 en University of Stellenbosch 130 leaves : ill. application/pdf Stellenbosch : University of Stellenbosch
spellingShingle Dissertations -- Mechanical engineering
Turbo-machinery
Blade root geometries
Turbomachines -- Blades
Blades -- Mathematical models
Photoelasticity
Hettasch, Georg
Optimization of fir-tree-type turbine blade roots using photoelasticity
title Optimization of fir-tree-type turbine blade roots using photoelasticity
title_full Optimization of fir-tree-type turbine blade roots using photoelasticity
title_fullStr Optimization of fir-tree-type turbine blade roots using photoelasticity
title_full_unstemmed Optimization of fir-tree-type turbine blade roots using photoelasticity
title_short Optimization of fir-tree-type turbine blade roots using photoelasticity
title_sort optimization of fir tree type turbine blade roots using photoelasticity
topic Dissertations -- Mechanical engineering
Turbo-machinery
Blade root geometries
Turbomachines -- Blades
Blades -- Mathematical models
Photoelasticity
url http://hdl.handle.net/10019.1/993
work_keys_str_mv AT hettaschgeorg optimizationoffirtreetypeturbinebladerootsusingphotoelasticity