The design of an ultrasonic array and its settings for a specific inspection involves multiple parameters: number and arrangement of elements, frequency, etc. A compromise between requirements (e.g. beam characteristics) and limitations (e.g. number of elements) is often prospected using parametric studies based on simulation tools to ensure that the transducer has suitable performances in terms of detection of the defects sought. An automatic optimization method, based on an evolutionary algorithm and numerical simulation, has been proposed and adapted to meet the specificities of the non-destructive testing applications. The performances of the method are evaluated for two cases of application to evaluate the influence of the different tuning parameters, and to compare the results by defining two or three objective functions to optimize the same problem.