Patent ID: 11859516
Assignee: GENERAL ELECTRIC COMPANY
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F | IPC F

Claim 22:
23. A gas turbine engine defining a centerline and a circumferential direction, the gas turbine engine comprising:
a turbomachine comprising a compressor section, a combustion section, and a turbine section arranged in serial flow order, the turbomachine defining a working gas flowpath and a fan duct flowpath;
a primary fan driven by the turbomachine defining a primary fan tip radius R1 and a primary fan hub radius R2;
a secondary fan located downstream of the primary fan and driven by the turbomachine, at least a portion of an airflow from the primary fan configured to bypass the secondary fan, the secondary fan defining a secondary fan tip radius R3 and a secondary fan hub radius R4, wherein the secondary fan is configured to provide a fan duct airflow through the fan duct flowpath during operation to generate a fan duct thrust, wherein the fan duct thrust is equal to % Fn3S of a total engine thrust during operation at a rated speed during standard day operating conditions;
wherein a ratio of R1 to R3 equals, (
     EFP
     )
    
    ⁢
    
     
      (
      
       1
       -
       
        R
        ⁢
        q
        ⁢
        
         R
         
          
           Sec
           .
           
            -
            Fa
           
          
          ⁢
          
           n
           2
          
         
        
       
      
      )
     
     
      (
      
       1
       -
       
        R
        ⁢
        q
        ⁢
        
         R
         
          
           Prim
           .
           
            -
            Fa
           
          
          ⁢
          
           n
           2
          
         
        
       
      
      )
     
    
    ⁢
    
     (
     
      
       1
       
        %
        ⁢
           
        
         Fn
         
          3
          ⁢
          S
         
        
       
      
      -
      1
     
     )
    
   
  
  ;
 

wherein EFP is between 1.5 and 11, wherein RqRPrim.-Fan is a ratio of R2 to R1, and wherein RqRSec.-Fan is a ratio of R4 to R3.