US 11,994,089 B2
After-fan system for a gas turbine engine
Dmitriy B. Sidelkovskiy, Ellington, CT (US); Pitchaiah Vijay Chakka, Avon, CT (US); Michael Winter, New Haven, CT (US); and Daniel Bernard Kupratis, Wallingford, CT (US)
Assigned to RTX Corporation, Farmington, CT (US)
Filed by United Technologies Corporation, Farmington, CT (US)
Filed on Apr. 1, 2020, as Appl. No. 16/837,143.
Claims priority of provisional application 62/831,953, filed on Apr. 10, 2019.
Prior Publication US 2020/0325852 A1, Oct. 15, 2020
Int. Cl. F02K 3/06 (2006.01); F04D 29/32 (2006.01); F01D 17/16 (2006.01); F02C 7/36 (2006.01)
CPC F02K 3/06 (2013.01) [F04D 29/323 (2013.01); F01D 17/162 (2013.01); F02C 7/36 (2013.01); F05D 2220/323 (2013.01); F05D 2220/36 (2013.01); F05D 2240/12 (2013.01); F05D 2240/35 (2013.01); F05D 2260/40311 (2013.01); F05D 2260/74 (2013.01); F05D 2260/79 (2013.01)] 20 Claims
OG exemplary drawing
 
17. A method of generating thrust fora gas turbine engine, comprising:
rotating a fan section with an array of fan blades;
rotating a short span after-fan turbine downstream of the fan section, said short span after-fan turbine being positioned between an outer profile of a core static structure and a ring splitter located radially inboard of an inner periphery of a fan nacelle, the short span after-fan turbine being contained radially within the ring splitter, wherein the short span after-fan turbine extracts a portion of energy from a compressed bypass flow from the fan section and return the portion of the energy to the fan section through torque; and
varying a pitch of a variable pitch fan exit guide vane array downstream of the fan section and upstream of the short span after-fan turbine.
 
1. An after-fan system for a gas turbine engine, comprising:
a variable pitch fan exit guide vane array;
an after-fan turbine downstream of the variable pitch fan exit guide vane array, wherein the after-f an turbine is configured to extract a portion of energy from a compressed bypass flow from a fan section and return the portion of the energy to the fan section through torque; and
a control operable to vary a pitch of the variable pitch fan exit guide vane array.