Using Taguchi method for designing wedge-shaped structures for an acoustically non-reflecting test section

Abstract

In the present article, optimal design of a wedge-shaped structure that is added to an acoustically non-reflecting test section in a cavitation tunnel is examined. This is done to decrease the propeller noise propagation. The proposed structure resembles a check valve which causes the propagated sound to be trapped in a space between the wedge-shaped structure and the wall. Sound loses its energy due to receiving a multitude of impacts. The acoustic analyses are performed for the source located in the center and three other asymmetrical sources. Initially, five parameters are analyzed on three levels and 27 tests are designed applying Taguchi’s method. After 27 tests, optimal values of the designated parameters are found for the sound source located at the center. To obtain more accurate values, the parameters are defined at five levels around the optimally obtained values and 25 tests are designed for each source. Finally, following 100 tests, the accurate optimal values of the considered parameters are obtained. Analyzing the final structure, the calculated results compared with 100 tests, displays the highest performance.