A method comprising: attaching a plurality of piezoelectric transducers (12A-12D) to a plurality of locations of an exterior of an additive-manufactured part having internal passages (14A-14F) terminating at one or more open ends at the exterior of the part; vibrating the part by driving the plurality of piezoelectric transducers (12A-12D) at varying amplitudes and frequencies; monitoring an amount of unfused powder that exits the one or more open ends at the exterior of the part; in response to determining that the amount of unfused powder that exits the one or more open ends exceeds a threshold deviation from an estimated amount of unfused powder contained within the internal passages (14A-14F) of the part: changing at least one of an orientation of the part and locations of one or more of the plurality of piezoelectric transducers (12A-12D); based on known orientations of the internal passages (14A-14F) within the part; and repeating the vibrating and monitoring steps by driving the plurality of piezoelectric transducers (12A-12D) at the varying amplitudes and frequencies and monitoring the amount of unfused powder that exits the one or more open ends at the exterior of the part; and in response to determining that the amount of unfused powder that exits the one or more open ends does not exceed the threshold deviation from the estimated amount of unfused powder contained within the internal passages (14A-14F) of the part: creating a defined schedule of frequency changes, amplitude changes, orientation changes, and transducer locations associated with the part; wherein altering the orientation of the part based on the known orientations of the internal passages (14A-14F) within the part comprises identifying the known orientations of the internal passages using a computer model of the part, or wherein altering the orientation of the part based on the known orientations of the internal passages within the part comprises identifying that one or more of the internal passages changes direction within the part, or wherein altering the orientation of the part comprises altering the orientation of the part based on the amount of the unfused powder that exits the part. attaching a plurality of piezoelectric transducers (12A-12D) to a plurality of locations of an exterior of an additive-manufactured part having internal passages (14A-14F) terminating at one or more open ends at the exterior of the part; vibrating the part by driving the plurality of piezoelectric transducers (12A-12D) at varying amplitudes and frequencies; monitoring an amount of unfused powder that exits the one or more open ends at the exterior of the part; in response to determining that the amount of unfused powder that exits the one or more open ends exceeds a threshold deviation from an estimated amount of unfused powder contained within the internal passages (14A-14F) of the part: changing at least one of an orientation of the part and locations of one or more of the plurality of piezoelectric transducers (12A-12D); based on known orientations of the internal passages (14A-14F) within the part; and repeating the vibrating and monitoring steps by driving the plurality of piezoelectric transducers (12A-12D) at the varying amplitudes and frequencies and monitoring the amount of unfused powder that exits the one or more open ends at the exterior of the part; and changing at least one of an orientation of the part and locations of one or more of the plurality of piezoelectric transducers (12A-12D); based on known orientations of the internal passages (14A-14F) within the part; and repeating the vibrating and monitoring steps by driving the plurality of piezoelectric transducers (12A-12D) at the varying amplitudes and frequencies and monitoring the amount of unfused powder that exits the one or more open ends at the exterior of the part; and in response to determining that the amount of unfused powder that exits the one or more open ends does not exceed the threshold deviation from the estimated amount of unfused powder contained within the internal passages (14A-14F) of the part: creating a defined schedule of frequency changes, amplitude changes, orientation changes, and transducer locations associated with the part; creating a defined schedule of frequency changes, amplitude changes, orientation changes, and transducer locations associated with the part; wherein altering the orientation of the part based on the known orientations of the internal passages (14A-14F) within the part comprises identifying the known orientations of the internal passages using a computer model of the part, or wherein altering the orientation of the part based on the known orientations of the internal passages within the part comprises identifying that one or more of the internal passages changes direction within the part, or wherein altering the orientation of the part comprises altering the orientation of the part based on the amount of the unfused powder that exits the part.