Accession Number : ADA181763
Title : Aeroelasticity in Turbomachines. Comparison of Theoretical and Experimental Cascade Results.
Descriptive Note : Final rept. 2 May 84-1 Nov 85,
Corporate Author : ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE (SWITZERLAND) LAB DE THERMIQUE APPLIQUEE
Personal Author(s) : Boelcs,A ; Fransson,T H
PDF Url : ADA181763
Report Date : Jan 1986
Pagination or Media Count : 235
Abstract : The aeroelastician needs reliable, efficient methods for calculating unsteady blade forces in turbomachines. The validity of such theoretical or empirical prediction models can be established only if researchers apply their flutter and forced vibration predictions to a number of well documented experimental test cases. In the present report, the geometrical and time-averaged flow conditions of nine two-dimensional and quasi-three-dimensional experimental (mainly) standard configurations for aeroelasticity in turbomachine-cascades are given. Some aeroelastic test cases are defined for each configuration, comprising different incidence angles, Mach numbers, interblade phase angle, reduced frequencies, etc. Furthermore, a proposal for uniform nomenclature and reporting formats is included, in order to facilitate the comparison of different experimental data and theoretical results. In total, results from 15 theoretical prediction methods have been compared with each other, and with experimental data. The comparative investigation has shown that present theoretical models can predict accurately the aeroelastic behavior of certain cascade configurations in two-dimensional flow. Other configurations, on the other hand, cannot be predicted as well. It is concluded that, although present methods can predict stability limits in some cases, the physical reasons for flutter in cascades are not yet fully understood. Further investigations, both experimental and theoretical, are thus urgently required. (Switzerland).
Descriptors : *AEROELASTICITY, *CASCADE STRUCTURES, *TURBOMACHINERY, MODELS, VIBRATION, FLOW, GEOMETRY, MACH NUMBER, FLUTTER, ANGLE OF INCIDENCE, REDUCTION, UNSTEADY FLOW, TURBINE BLADES, DYNAMIC PRESSURE, SUCTION, COMPARISON, EXPERIMENTAL DATA, EFFICIENCY, METHODOLOGY, RELIABILITY, SWITZERLAND, MATHEMATICAL PREDICTION, THEORY, STABILITY, MEAN, TWO DIMENSIONAL FLOW
Subject Categories : Hydraulic and Pneumatic Equipment
Radiofrequency Wave Propagation
Distribution Statement : APPROVED FOR PUBLIC RELEASE