Simplified method and apparatus for hot-shield jet noise suppression
AssigneeThe Boeing Company
InventorGarry W. Klees
Life of this patent
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Abstract
A method and apparatus for selectively generating a noise suppressing hot gas shield are described. A portion of the jet engine exhaust flow is selectively directed to a nozzle which at least partially surrounds the circumference of the jet engine exhaust. Prior to exiting the nozzle the flow is passed through a pressure, and therefore density, loss producing device to provide a shield flow of optimum noise suppression properties.
Claims13
A method of suppressing the noise of a jet engine having an exhaust duct through which the hot exhaust flow passes comprising the steps of
- forming a shield duct adjacent said exhaust duct, deflecting a portion of said hot exhaust flow from its path,
- directing said deflected portion into said shield duct,
- reducing the pressure of said deflected portion as said portion passes through said shield duct
- ejecting said portion to the atmosphere from said shield duct at a location downstream of that where said pressure reduction occurs to form a sound suppressing fluid layer.
Means for suppressing the noise of a jet engine having an exhaust duct through which passes a hot exhaust flow, comprising,
- means forming a shield duct open to the atmosphere at an exit end thereof at least part way around the circumference of said exhaust duct,
- means upstream of the exit of said shield duct for reducing the pressure of a fluid flow passing therethrough, and
- means for permitting at least some of said exhaust flow to enter said shield duct means, whereby said flow passes through said pressure reducing means and is then expelled to the atmosphere to form a noise suppressing fluid shield layer.
Dependencies are inferred from the claim text.