US 7,500,352 B2
Gas turbine engine
Stephen J. Bradbrook, Bristol (United Kingdom)
Assigned to Rolls-Royce PLC, London (United Kingdom)
Filed on May 23, 2005, as Appl. No. 11/134,278.
Claims priority of application No. 0411943.4 (GB), filed on May 28, 2004; and application No. 0509813.2 (GB), filed on May 12, 2005.
Prior Publication US 2006/0016172 A1, Jan. 26, 2006
Int. Cl. F02K 3/04 (2006.01)
U.S. Cl. 60—226.1  [415/77] 13 Claims
OG exemplary drawing
 
1. A gas turbine engine comprising:
a fan unit in flow relationship with an engine core and a bypass duct, the fan unit having a plurality of fans, each fan defined by having a plurality of blade elements extending radially to an outer casing,
the engine core and bypass duct being in parallel flow relationship with each other and each of which are provided with an intake and exhaust,
said engine core further comprising a compressor, a combustor and a turbine, with an inner casing provided around said engine core which radially defines an engine core intake, the engine core intake being downstream of a rear-most fan of the fan unit;
said bypass duct being radially defined by the outer casing radially spaced apart from said fan unit and said inner casing along at least part of the length of the gas turbine engine and having an entry point downstream of the rear-most fan of the fan unit; and
bypass air compression means for compressing air flowing through the bypass duct such that, under substantially all engine power conditions, air at exit from the bypass duct is at a greater total pressure than air delivered to the engine core intake.