General shell model for a rotating pretwisted blade
2013 (English)In: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 332, no 22, 5804-5820 p.Article in journal (Refereed) Published
A novel dynamic model for a pretwisted rotating compressor blade mounted atan arbitrary stagger angle using general shell theory and including the rotationalvelocity is developed to study the eigenfrequencies and damping properties of thepretwisted rotating blade. The strain-displacement relation and constitutive modelbased on the general (thick) shell theory are applied to bring out the strain energyof the rotating blade. Using the Hamilton’s principle, the variational form of thetotal energy is derived in order to obtain the corresponding weak form for thenumerical simulation. The model is validated by comparing to literature resultsand Ansys results, showing good agreement. Parametric analyses are carried outto study the influence of the rotation velocity, the stagger angle and the radius ofthe disk on the eigenfrequencies of the pretwisted blade. Proportional dampingis included into the proposed model to investigate the influence of rotational velocityon the damping characteristics of the pretwisted rotating blade system. It isshown that, due to inertial and Coriolis eects, damping decreases as the rotation velocity increases for the lower part of the velocity range considered and eitherdecreases or increases depending on the mode order for higher velocities. Furthermore,frequency loci veering as a result of the rotation velocity is observed.The proposed model is an ecient and accurate tool for predicting the dynamicbehavior of compressor blades of arbitrary thickness, stagger angle and pretwist,potentially during the early designing stage of turbomachinery.
Place, publisher, year, edition, pages
Elsevier, 2013. Vol. 332, no 22, 5804-5820 p.
Rotating pretwisted blade, Shell theory, Damping prediction
IdentifiersURN: urn:nbn:se:kth:diva-101239DOI: 10.1016/j.jsv.2013.06.025ISI: 000323361000010ScopusID: 2-s2.0-84880923598OAI: oai:DiVA.org:kth-101239DiVA: diva2:546883
FunderSwedish Energy Agency
QC 201307232012-08-252012-08-252013-09-12Bibliographically approved