Similitude method for self-noise under boundary layer pressure fluctuation excitation

Area of Science:

• Acoustics
• Fluid Dynamics
• Aerodynamics

Background:

• Flow-induced noise is a significant concern in engineering applications.
• Predicting noise from full-scale models using smaller ones is challenging.
• Understanding boundary layer pressure fluctuations is key to noise prediction.

Purpose of the Study:

• To propose and validate a similitude method for predicting full-scale flow-induced noise from small-scale model data.
• To investigate theoretical aspects of similitude and flow regime control.
• To analyze the accuracy and error of the proposed prediction method.

Main Methods:

• Application of the Π-theorem for similitude.
• Investigation of active and passive flow regime control techniques.
• Computational Fluid Dynamics (CFD) analysis of plate and rotary models.
• Error analysis to validate prediction accuracy.

Main Results:

• The proposed similitude method accurately predicts full-scale flow-induced noise based on small-scale model observations.
• CFD analysis confirmed the effectiveness of the method for both plate and rotary models.
• Error analysis demonstrated the reliability of the noise prediction.

Conclusions:

• The similitude method based on the Π-theorem is a viable tool for predicting flow-induced noise.
• Accurate noise prediction is achievable by scaling down models and controlling flow regimes.
• The study provides a robust framework for aerodynamic noise assessment.