Investigation of unsteady aerodynamic blade excitation mechanisms in a transonic turbine stage - Part II: Analytical description and quantification
2002 (English)In: Journal of turbomachinery, ISSN 0889-504X, Vol. 124, no 3, 419-428 p.Article in journal (Refereed) Published
This paper presents a study of the blade pressure perturbation levels and the resulting blade forces in a high-pressure transonic turbine stage based on 3-D time dependent viscous computations. Globally, the blade pressure unsteadiness is quantified with the RMS of the pressure perturbations integrated in both time and along the blade surface. Operation point as well as spanwise variations are addressed. Locally, the relative strength of the pressure perturbation events on the vane and rotor blade surface is investigated. To obtain information about the relative strength of events related to the blade passing frequency and higher harmonics, the pressure field is Fourier decomposed in time at different radial positions along the blade arc-length. The amplitude peaks are then related to the pressure events in space-time maps. With the help of the observations and results from the blade pressure study, the radial variations of the unsteady blade force and torque acting on a constant span blade profile section are investigated. The connection between the first and second vane passing frequency pressure amplitudes on the rotor blade surface and the resulting force and the torque amplitudes for three selected blade modes was investigated in detail. In this investigation the pressure was integrated over defined rotor blade regions to quanti,, local force contributions. Spanwise as well as operation point variations are addressed.
Place, publisher, year, edition, pages
2002. Vol. 124, no 3, 419-428 p.
IdentifiersURN: urn:nbn:se:kth:diva-21744DOI: 10.1115/1.1458579ISI: 000177013500014OAI: oai:DiVA.org:kth-21744DiVA: diva2:340442
QC 20100525 QC 201111292010-08-102010-08-102011-11-29Bibliographically approved