The propeller design is an activity which nowadays presents ever increasing challenges to the designer, involving not only the usual mechanical characteristics fulfillment and cavitation erosion avoidance, but also other cavitation side effects, such as radiated noise and/or pressure pulses. Moreover, in some cases propeller characteristics have to be optimized in correspondence to very different functioning points, including considerably off-design conditions, hardly captured by conventional design methods. In the present paper, a recently presented method, based on the coupling between a multiobjective optimization algorithm and a panel code, is applied to the design of a CPP propeller at different pitch settings, with the aim of reducing the cavitating phenomena and, consequently, the resultant radiated noise. Particular attention has been devoted to the slow speed (low pitch) condition, obtained at constant RPM, and characterized by considerable radiated noise and vibrations related to face cavitation. Numerical results are validated by means of an experimental campaign, testing both the original and the optimized geometry in terms of cavitation extent and radiated noise. Experimental results confirm the numerical predictions, attesting the capability of the method to assess propeller functioning characteristics, thus representing a very useful tool for the designer in correspondence of challenging problems. © 2012 Elsevier Ltd. All rights reserved.
CPP propeller cavitation and noise optimization at different pitches with panel code and validation by cavitation tunnel measurements
BERTETTA, DANIELE;BRIZZOLARA, STEFANO;GAGGERO, STEFANO;VIVIANI, MICHELE;SAVIO, LUCA
2012-01-01
Abstract
The propeller design is an activity which nowadays presents ever increasing challenges to the designer, involving not only the usual mechanical characteristics fulfillment and cavitation erosion avoidance, but also other cavitation side effects, such as radiated noise and/or pressure pulses. Moreover, in some cases propeller characteristics have to be optimized in correspondence to very different functioning points, including considerably off-design conditions, hardly captured by conventional design methods. In the present paper, a recently presented method, based on the coupling between a multiobjective optimization algorithm and a panel code, is applied to the design of a CPP propeller at different pitch settings, with the aim of reducing the cavitating phenomena and, consequently, the resultant radiated noise. Particular attention has been devoted to the slow speed (low pitch) condition, obtained at constant RPM, and characterized by considerable radiated noise and vibrations related to face cavitation. Numerical results are validated by means of an experimental campaign, testing both the original and the optimized geometry in terms of cavitation extent and radiated noise. Experimental results confirm the numerical predictions, attesting the capability of the method to assess propeller functioning characteristics, thus representing a very useful tool for the designer in correspondence of challenging problems. © 2012 Elsevier Ltd. All rights reserved.
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