Prediction of vibration characteristics of blisks using similitude models

Abstract

This study investigates the determination approach of distorted scaling laws for predicting the dynamic characteristic of an aero engine’s blisk. Based on the dynamic scaling laws of typical thin-walled structures, an assumption of geometrically complete scaling laws is firstly proposed and numerically validated. For distorted models of disk thickness, in order to simplify the design procedure, a simplification condition is proposed and applied to the first 10 orders’ distorted scaling laws (blade-dominated vibrations) by combining sensitivity analysis. Next, the 11th–14th orders’ distorted scaling laws are determined for disk-dominated vibrations. Numerical validation demonstrates that distorted scaling laws possess a good accuracy. Finally, the applicability of these new scaling laws is validated by the experimental data. The results indicate that, by using the new scaling laws, the simple models can predict vibration characteristics of blisk by employing similitude models.

Keywords:

• Blisk
• distorted
• scaling law
• similitude
• vibration

Additional information

Funding

This work was supported by the National Science Foundation of China [grant numbers 11572082]; the Fundamental Research Funds for the Central Universities of China [grant numbers N160312001, N150304004]; and the Excellent Talents Support Program in Institutions of Higher Learning in Liaoning Province of China [grant numbers LJQ2015038].