Multi-resonance flextensional low frequency acoustic projector

A multi-resonance flextensional low frequency acoustic projector for generating acoustic waves by converting vibration of a piezoelectric element, the projector comprising:

• a piezoelectric actuator 110;
• a plurality of staves 120 attached to an outer surface of the piezoelectric actuator 110 to convert longitudinal vibration generated by the piezoelectric actuator 110 into lateral vibration perpendicular to the outer surface of the piezoelectric actuator 110;
• and
• an acoustic window 130 surrounding an exterior of the plurality of staves 120 and water-tightening the inside of the projector 100, wherein
• the plurality of staves 120 is configured of a convex stave 121 and a concave stave 122 to have different resonance frequencies from each other to generate two or more types of resonance vibration modes.

A multi-resonance flextensional low frequency acoustic projector for generating acoustic waves by converting vibration of a piezoelectric element, the projector comprising:

• a piezoelectric actuator 110;
• a plurality of staves 120 attached to an outer surface of the piezoelectric actuator 110 to convert longitudinal vibration generated by the piezoelectric actuator 110 into lateral vibration perpendicular to the outer surface of the piezoelectric actuator 110;
• an acoustic window 130 surrounding an exterior of the plurality of staves 120 and water-tightening the inside of the projector 100;
• and
• an inner space 140 filled with air between the plurality of staves 120 and the piezoelectric actuator 110,
• wherein the piezoelectric actuator 110 includes:
• a piezoelectric stack 111 in which piezoelectric elements 111a are stacked to generate vibration in a longitudinal direction by an input electric signal;
• and
• a pair of flange 112 that surface-contacts both end portions of the piezoelectric stack 111,
• wherein the plurality of staves 120 is configured of a convex stave 121 and a concave stave 122 to have different resonance frequencies from each other to generate two or more types of resonance vibration modes.