Centrifugal impeller with forward and reverse flow paths

Abstract

A centrifugal impeller having an inlet and a plurality of outlets, the outlets including at least one outlet in a forward direction of the impeller and at least one outlet in a rearward direction of the impeller. A flow path distance of the outlet in the forward direction can be greater than a flow path distance of the outlet in the rearward direction in order to provide a greater pressure in the outlet having the greater flow path distance. In another embodiment, the flow path volume in the forward direction can be greater than the flow path volume in the rearward direction in order to provide a greater flow volume in the forward direction. In another embodiment, the number of flow paths in the forward direction can be greater than the number of flow paths in the rearward direction in order to provide a greater flow volume in the forward direction. The impeller is also used in a gas turbine engine in which the impeller also includes a turbine blade, and the forward directing outlets deliver compressed air to a combustor while the rearward directed outlets bypass the combustor.

1 . A centrifugal impeller, comprising: 
 A common inlet;    A plurality of flow paths in communication with the common inlet;    A plurality of outlets, each outlet associated with a respective flow path; and,    At least one of the plurality of outlets being arranged to direct fluid flow substantially in a forward direction of the impeller, and at least one of the plurality of outlets being arranged to direct fluid flow substantially in a rearward direction of the impeller.    
   
   
       2 . The impeller of  claim 1 , and further comprising: 
 The at least one outlet in the forward direction has a flow path distance through the impeller greater than a flow path distance through the impeller of the outlet in the rearward direction.    
   
   
       3 . The impeller of  claim 1 , and further comprising: 
 A number of forward flow paths is equal to a number of rearward flow paths.    
   
   
       4 . The impeller of  claim 1 , and further comprising: 
 A number of forward flow paths is greater than a number of rearward flow paths.    
   
   
       5 . The impeller of  claim 1 , and further comprising: 
 A number of forward flow paths is less than a number of rearward flow paths.    
   
   
       6 . The impeller of  claim 1 , and further comprising: 
 A size of the forward flow path is greater than a size of the rearward flow path such that a greater volume of fluid flows in the forward flow path than does in the rearward flow path.    
   
   
       7 . A gas turbine engine, comprising: 
 A centrifugal impeller having an inlet and a plurality of outlets;    A combustor arranged adjacent to the impeller;    An outlet for the gas turbine engine;    A turbine blade rotatably secured to the impeller;    The impeller having at least one of the plurality of outlets directed toward the combustor, and the impeller having at least one of the plurality of outlets directed toward a bypass of the combustor, whereby the outlet directed toward the combustor provides compressed air for combustion and the outlet directed toward the bypass provides a bypass flow for the gas turbine engine.    
   
   
       7 . The gas turbine engine of  claim 7 , and further comprising: 
 A number of outlets in the impeller directed toward the combustor are equal to the number of outlets directed toward the bypass.    
   
   
       8 . The gas turbine engine of  claim 7 , and further comprising: 
 The outlet directed toward the combustor has a flow path distance in the impeller greater than a flow path distance in the impeller of the outlet directed to the bypass.    
   
   
       9 . The gas turbine engine of  claim 7 , and further comprising: 
 A number of outlets in the impeller directed toward the combustor are greater than the number of outlets directed to the bypass.    
   
   
       10 . The gas turbine engine of  claim 7 , and further comprising: 
 A size of the fluid passage of the outlet directed toward the combustor is greater than a size of the fluid passage of the outlet directed toward the bypass.    
   
   
       11 . A process for operating a gas turbine engine, the process comprising the steps of: 
 Providing for a centrifugal impeller and rotor assembly;    Providing for a combustor adjacent to the impeller and rotor assembly;    Providing for the impeller and rotor assembly to include at least one outlet to supply a compressed air to the combustor;    Providing for the impeller and rotor assembly to include at least one outlet to bypass the combustor;    Providing for the impeller and rotor assembly to include at least one turbine blade; and,    Providing for a gas flow from the combustor to be directed against the turbine blade on the impeller and rotor assembly.    
   
   
       11 . The process for operating a gas turbine engine of  claim 11 , and further comprising the step of: 
 Providing for the outlet directed to the combustor to have a greater flow path distance in the impeller greater than a flow path distance in the impeller of the outlet directed to the bypass.    
   
   
       12 . The process for operating a gas turbine engine of  claim 11 , and further comprising the step of: 
 Providing for the impeller and rotor assembly to have an equal number of outlets directed toward the combustor as a number of outlets directed toward the bypass.    
   
   
       13 . The process for operating a gas turbine engine of  claim 11 , and further comprising the step of: 
 Providing for the impeller and rotor assembly to have a greater number of outlets directed toward the combustor as a number of outlets directed toward the bypass.    
   
   
       14 . The process for operating a gas turbine engine of  claim 11 , and further comprising the step of: 
 Providing for the outlet directed toward the combustor to have a greater flow volume than the outlet directed toward the bypass.