During fast gas-turbine engine acceleration and deceleration the transient vibration effects in bladed disk vibration become significant and the transient response have to be calculated. &nbsp;&nbsp;In this paper an effective method is developed for efficient calculations of the transient vibration response for mistuned bladed disks under varying rotation speeds. The method uses the large-scale finite element modelling of the bladed disks allowing the accurate description of the dynamic properties of the mistuned bladed disks.The effects of the varying rotation speed on the natural frequencies and mode shapes of a mistuned bladed disk and its effects on the amplitude and the spectral composition of the loading are allowed for. The dependency of the modal characteristics on the rotation speed are based on the evaluation of these characteristics at reference points followed by the interpolation to obtain values at any rotation speed from the operating range. The interpolation of mode shapes preserves the orthogonality of the modes shapes and their mass-normalisation property. The problem of the interpolation of rotation speed-dependent mode shapes has not been considered before – in contrast to the much more simple and trivial problem of interpolation of the natural frequencies. A new method has been developed to accurate interpolate the mode shapes while keeping their properties, which allows the transient response calculation with considering effects of the bladed disc rotation.The method of mode shape interpolation is developed for tuned and mistuned bladed disks. The accuracy and efficiency of the method is demonstrated on test examples and on analysis of &nbsp;transient forced response of realistic bladed discs.

Accurate Interpolation of the Dependency of Modal Properties on the Rotation Speed for the Transient Response Analysis of Bladed Discs

Paper Proceedings: https://asmedigitalcollection.asme.org/GT/GT2021/volume/84898

Turbo Expo 2021

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.