Bubble Dynamics Effects on the Rotordynamic Forces in Cavitating Inducers
Abstract
The present work investigates the dynamics of idealized bubbly and cavitating flows in whirling helical inducers, with the purpose of understanding the impact of the bubble response on the rotordynamic forces exerted by the fluid on the turbomachine under cavitating conditions. Inertial, damping, and compressibility effects in the dynamics of the bubbles are included. The effect of the whirl excitation on the two-phase flow is dependent on the wave propagation speed and the bubble resonance behavior in the bubbly mixture. These, in turn, lead to rotordynamic forces which are complicated functions of the whirl frequency and depend on the void fraction of the bubbles and on the mean flow properties. Under cavitating conditions the dynamic response of the bubbles induces major deviations from the non-cavitating flow solutions. The quadratic dependence of rotordynamic fluid forces on the whirl speed, which is typical of cavitation-free operation is significantly modified. Results are presented to illustrate the influence of the various flow parameters.
Additional Information
This work has been supported by the Italian Department of Universities and Scientific & Technologic Research under the 1993 grant program for academic research and by the Office of Naval Research under grant number N-00014-91-K-1295. Some of the authors would like to express their gratitude to Profs. Mariano Andrenucci and Renzo Lazzeretti of the Aerospace Engineering Department of Pisa University, Pisa, Italy, for their encouragement in the completion of the present work.Attached Files
Published - DAU152.pdf
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Additional details
- Eprint ID
- 92
- Resolver ID
- CaltechAUTHORS:DAUcmff95
- Italian Department of Universities and Scientific & Technologic Research
- Office of Naval Research (ONR)
- N-00014-91-K-1295
- Created
-
2004-09-24Created from EPrint's datestamp field
- Updated
-
2019-10-02Created from EPrint's last_modified field
- Series Name
- Fluids Engineering Division
- Series Volume or Issue Number
- 210