Claims
- 1. In a variable bypass turbofan engine having a bypass duct surrounding a core engine, a fan disposed in flow communication with said bypass duct and said core engine, and a hinged valve door positionable between open and closed positions in said bypass duct, a method of controlling airflow through said bypass duct comprising generating differential pressure between said fan and said bypass duct and automatically positioning said valve door in response to said differential pressure across said valve door.
- 2. A method according to claim 1 wherein said engine further includes an augmentor having a combustion liner disposed in flow communication with said bypass duct and said core engine, and a rear variable area bypass injector (VABI) disposed between said core engine and said augmentor liner, and said method further includes opening and closing said rear VABI for selectively channeling portions of airflow from said bypass duct to inside said liner for generating said differential pressure.
- 3. A method according to claim 2 wherein said engine is a double bypass turbofan engine having a plurality of circumferentially disposed ones of said hinged valve doors disposed as a first bypass between an upstream end of said bypass duct and said fan, and said engine further includes a second bypass defined by an annular opening and a bypass injector operatively disposed therein downstream of said first bypass in an intermediate portion of said bypass duct for bypassing a portion of compressed airflow from said core engine into said bypass duct, and said method further includes opening said rear VABI for channeling bypass airflow inside said augmentor liner for generating a positive differential pressure to open said hinged valve doors for double bypass operation of said engine.
- 4. A method according to claim 3 further including closing said rear VABI for generating a negative differential pressure to close said hinged valve doors for single bypass operation of said engine.
Parent Case Info
This application is a division of application Ser. No. 07/522,024, filed May 11, 1990, pending.
Government Interests
This invention was made with Government support Contract No. F33657-83-C-0281 awarded by the Department of the Air Force. The Government has certain rights in this invention.
US Referenced Citations (7)
Divisions (1)
|
Number |
Date |
Country |
Parent |
522024 |
May 1990 |
|