Emission signature modification device
An emission signature modification device for modifying an acoustic signature of an exhaust gas stream, including an exhaust gas guiding device that guides the exhaust gas stream in the flow direction thereof from an inlet area to an outlet area. An active acoustic emission modification device modifies the acoustic emission of the exhaust gas stream in predetermined operating states. If an actuator system of the active acoustic emission modification device is designed such that in a circumferential direction, the actuator system is surrounded by more than 30% of the guided exhaust gas stream, the actuating system can be protected against harmful influences from the environment by way of the exhaust gas guiding device on the one hand, and on the other hand, the required space signifier can be reduced as compared to a lateral, external arrangement of the actuating system.
1. An emission signature modification device for modification of an acoustic signature of an exhaust gas stream, comprising: an exhaust gas guiding device that guides the exhaust gas stream in a flow direction from an inlet region to an outlet region; and an active acoustic emission modification device, that modifies an acoustic emission of the exhaust gas stream in predetermined operating states, wherein the active acoustic emission modification device includes an actuator system, wherein more than 30% of the actuator system is surrounded in a circumferential direction by the guided exhaust gas stream, wherein the exhaust gas guiding device has an outer shell with a solid outer circumferential wall, wherein the exhaust gas guiding device includes an inner shell, wherein the exhaust gas stream is guided at least partially between the outer shell and the inner shell of the exhaust gas guiding device; and a heat emission modification device that modifies heat emission of the exhaust gas stream in predetermined operating states, wherein the heat emission modification device comprises a first cooling device having a first cooling fluid, wherein the first cooling device is completely within the outer circumferential wall of the outer shell and is formed at least partially by the outer shell so that the first cooling fluid flows through the outer shell.
2. The emission signature modification device according to claim 1 , wherein the inner shell has an extent that amounts to at least 1% of an extent of the outer shell in the flow direction.
3. The emission signature modification B device according to claim 1 , further comprising at least one component arranged within the outer shell to guide the exhaust gas stream.
4. The emission signature modification device according to claim 1 , wherein the outlet region has a cross-sectional area perpendicular to the flow direction that is 90% smaller than a central cross-sectional area of the emission signature modification device perpendicular to the flow direction.
5. The emission signature modification device according to claim 1 , wherein the emission signature modification device is designed for modification of a heat signature of the exhaust gas stream.
6. The emission signature modification device according to claim 1 , further comprising a second cooling device having a second cooling fluid by which the actuator system is cooled.
7. The emission signature modification device according to claim 6 , wherein the first cooling device is fluidically connected to the second cooling device.
8. The emission signature modification device according to claim 1 , wherein the active acoustic emission modification device includes an acoustic diaphragm driven by the actuator system, wherein the acoustic diaphragm is water-resistant.
9. The emission signature modification device according to claim 8 , wherein the acoustic diaphragm is seawater-resistant.
10. The emission signature modification device according to claim 1 , wherein the emission signature modification device is a separate subassembly, which, in the flow direction, is positionable centrally or at an end in an exhaust section.