A closed-cycle combustion low-frequency acoustic pulse source for use underwater. An elongated combustion chamber, having a first end and a second end and an elongated elastic sleeve, is filled with a stoichiometric mixture of oxygen and hydrogen from an electrolyzer. When the mixture is ignited at the first end of the chamber, a longitudinally traveling flame front is initiated at the first end of the chamber. The moving front results in a traveling thermal pressure pulse. The pressure pulse is communicated to the surrounding underwater medium producing a generally uni-directional acoustic pressure pulse along the longitudinal axis of the elongated chamber. An alternative embodiment utilizes an array of sources disposed along the generally horizontal longitudinal axis of the array.
Thomas E. Owen