Shape optimization of acoustic horns for improved directivity control and radiation efficiency based on the...

Area of Science:

• Acoustics
• Mechanical Engineering
• Computational Physics

Background:

• Acoustic horns are crucial for controlling sound directivity and radiation efficiency.
• Optimizing horn shapes for wide frequency ranges presents significant design challenges.
• Existing methods may lack flexibility or computational efficiency for complex horn profiles.

Purpose of the Study:

• To develop and validate a multimodal method for optimizing axisymmetric acoustic horn shapes.
• To achieve well-controlled directivity and high radiation efficiency over a broad frequency spectrum.
• To provide an efficient and flexible alternative to conventional acoustic horn design approaches.

Main Methods:

• Utilizing a multimodal method to model arbitrary horn profiles by projecting wave fields onto transverse modes in connected cylinders.
• Employing cylinder radii as direct design variables within an optimization framework.
• Implementing a gradient-based optimization algorithm with algebraic gradient expressions.
• Adjusting design objectives (directivity, efficiency, smoothness) using coefficients in the objective function.

Main Results:

• Numerical experiments successfully generated smooth horn contours with significantly improved performance.
• The optimized horns demonstrated enhanced directivity and radiation efficiency over the target frequency band.
• A novel horn design exhibited desirable low-frequency loading properties, similar to earlier constant-directivity horns.

Conclusions:

• The proposed multimodal optimization method offers an effective approach for designing high-performance acoustic horns.
• The method provides a balance between design flexibility, computational accuracy, and performance optimization.
• This technique presents a viable and attractive alternative to traditional acoustic horn design strategies.