Active noise reduction in turbine machine flow channels involves driving actuators to generate secondary modes obtained by converting detected complex sound pressures

摘要

The method involves predetermining the primary sound field to identify the dominant acoustic azimuthal modes; determining the actuator transfer function; determining the modal transfer function for the peripheral modes without a primary sound field present; converting detected (7) complex sound pressures into acoustic azimuthal modes for at least one frequency component; computing secondary azimuthal modes to be produced by actuators (8) so that the sum of the primary and secondary modes per frequency component is a minimum; and driving the actuators to generate the secondary modes..