초록 ▼

A method of managing aircraft exhaust includes providing hot air at a hot air mass flow rate, providing cold air at a cold air mass flow rate, and mixing the hot air and the cold air at a variable hot air mass flow rate to cold air mass flow rate ratio, wherein the variable hot air mass flow rate to

A method of managing aircraft exhaust includes providing hot air at a hot air mass flow rate, providing cold air at a cold air mass flow rate, and mixing the hot air and the cold air at a variable hot air mass flow rate to cold air mass flow rate ratio, wherein the variable hot air mass flow rate to cold air mass flow rate ratio is selectively maintained independent of at least one of (1) a variation in the hot air mass flow rate and (2) a variation in a translational speed of the aircraft.

대표청구항 ▼

1. A method of managing aircraft exhaust, comprising: receiving hot air from an exhaust aircraft engine at a hot air mass flow rate, the aircraft engine configured to drive a rotor of the aircraft;providing the hot air at the hot air mass flow rate to a mixer duct of an exhaust system attached to th

1. A method of managing aircraft exhaust, comprising: receiving hot air from an exhaust aircraft engine at a hot air mass flow rate, the aircraft engine configured to drive a rotor of the aircraft;providing the hot air at the hot air mass flow rate to a mixer duct of an exhaust system attached to the exhaust duct;receiving cold air from outside the aircraft at a cold air mass flow rate through a first duct connecting the outside of the aircraft to a distributor disposed within the mixer duct, wherein a first fan is positioned within the first duct, and wherein the first fan is separate from the rotor;providing the cold air at the cold air mass flow rate to the distributor; andmixing the hot air and the cold air within the mixer duct at a variable hot air mass now rate to cold air mass flow rate ratio, wherein the hot air mass flow rate is varied using the aircraft engine and the cold air mass flow rate is varied by controlling a speed of the first fan positioned within the first duct, wherein the variable hot air mass flow rate to cold air mass flow rate ratio is selectively maintained independent of at least one of (1) a variation in the hot air mass flow rate and (2) a variation in a translational speed of the aircraft. 2. The method of claim 1, wherein the variation in the hot air mass flow rate is at least attributable to a variation in the engine speed. 3. The method of claim 1, wherein the variation in translational speed is at least partially attributable to a variation in an orientation of the engine exhaust system relative to a ground surface. 4. The method of claim 1, wherein the mixing comprises a variably controlled rate of film cooling. 5. The method of claim 1, wherein the mixing occurs in a space free of fan components. 6. The method of claim 1, wherein the mixing comprises preventing exhausted mixed air temperatures and surface temperatures of the exhaust system components that are visible from outside the aircraft from exceeding a selected temperature. 7. The method of claim 1, wherein at least some moving components of the first fan configured to selectively vary the cold air mass flow rate are not located in a path of unmixed hot air. 8. The method of claim 1, wherein the mixing comprises passing the hot air and the cold air through a substantially annular space defined by substantially round components. 9. The method of claim 1, wherein maintaining the variable hot air mass flow rate to cold air mass flow rate ratio reduces an infrared signature of the aircraft. 10. The method of claim 1, wherein the variable hot air mass flow rate to cold air mass flow rate ratio is equal to a value selected between 0.0 and 3.0, wherein the hot air has a hot air temperature, wherein a mixture comprising the hot air and the cold air has a mixture temperature, wherein the a ratio of the mixture temperature to the hot air temperature is equal to a value selected between 1.0 to about 0.338. 11. The method of claim 10, wherein at least one of the hot air and the cold air are supplied from multiple sources. 12. The method claim 1, further comprising maintaining the variable hot air mass flow rate to cold air mass flow rate ratio using one or more controllers. 13. The method claim 12, wherein maintaining the variable hot air mass flow rate to cold air mass flow rate ratio using the one or more controllers comprises selectively controlling the cold air mass flow rate based on factors comprising at least one of air temperature, surface temperature, pressure, or air flow. 14. The method of claim 1, further comprising: receiving cold air from outside the aircraft at a second cold air mass flow rate through a second duct connecting the outside of the aircraft to the mixer duct, wherein a second fan is positioned within the second duct, wherein the second fan is separate from the first fan and the rotor; andproviding the cold air at the second cold air mass flow rate to the mixer duct; andwherein mixing the hot air and the cold air within the mixer duct at a variable hot air mass flow rate to cold air mass flow rate ratio comprises mixing in the mixer duct the provided hot air, the cold air received through the first duct, and the cold air received through the second duct, and wherein the second cold mass flow rate is varied by controlling a speed of the second fan positioned within the second duct. 15. An exhaust system for an aircraft engine, the exhaust system comprising an exhaust duct connecting an aircraft engine to a mixer duct attached to the exhaust duct, the exhaust duct configured to provide hot air from the aircraft engine at a hot air mass flow rate to the mixer duct, wherein the hot air mass flow rate is varied by the aircraft engine, and wherein the aircraft engine is configured to drive a rotor of the aircraft; a first duct connecting an outside of the aircraft to a distributor disposed within the mixer duct of the exhaust system, the first duct configured to receive cold air from outside the aircraft at a cold air mass flow rate and provide the cold air at the cold air mass flow rate to the distributor;a first fan positioned within the first duct and separate from the rotor; anda controller configured to control a speed of the first fan positioned within the first duct to provide the cold air through the first duct at the cold air mass flow rate to the distributor; andwherein the mixer duct is configured to mix the hot air from the exhaust duct and the cold air from the first duct at a variable hot air mass flow rate to cold air mass flow rate ratio, independent of at least one of (1) a variation in the hot-air mass flow rate and (2) a variation in a translational speed of the aircraft. 16. The exhaust system of claim 15, further comprising: a second duct connecting the outside of the aircraft to the mixer duct, the second duct being separate from the first duct, wherein the second duct is configured to receive cold air from outside the aircraft at a second cold air mass flow rate and provide the cold air at the second cold air mass flow rate to the mixer duct; anda second fan position within the second duct and separate from the rotor, wherein the controller is configured to control a speed of the second fan positioned within the second duct to provide the cold air through the second duct at the second cold air mass flow rate to the mixer duct. 17. The exhaust system of claim 15, wherein the distributor comprises a distributor internal space at least partially bounded by a distributor wall and at least one distributor perforation through the distributor wall connecting the distributor internal space with the mixer duct. 18. The exhaust system of claim 15, wherein the exhaust system is configured for use with a tiltrotor aircraft.