In this article, characteristics of a well-designed horn are discussed. These characteristics are the uniformity of the vibration amplitude, longitudinal natural frequency, frequency separation, gain ratio, and maximum stress of the horn body. By considering these characteristics and using the Genetic Algorithm and constraint handling method, a procedure for the optimal design of wide blade horns is proposed. In this procedure, the uniformity of vibration amplitude is considered as the objective function and other characteristics are considered as the constraints. Based on this procedure, an optimization package is developed which is used to design an optimal wide horn. The results show that the longitudinal natural frequency of the horn is 0.125% higher than the target frequency. This horn has a high amplitude uniformity of 0.964. The frequency separation is more than 1 kHz, and the gain ratio is 1.6% lower than the target. Also, the maximum stress is lower than the endurance limit with a safety factor of 2.07. To verify the simulation results, a prototype horn is fabricated and tested. The comparison between simulation and experimental results shows a good agreement.
