Leakage flow minimization system for a turbine engine

Abstract

A sealing system is applied to the interface between a stator and a rotor in a turbine engine to minimize fluid leakage across the interface. One interface can be defined between portions of neighboring rotor disks and a stator. The sealing system includes one or more rows of flow guides, such as airfoils, provided on the rotor disk near the upstream end of the interface. These flow guides can impart tangential velocity on the leakage flow. One or more undulating seal structures can be connected to the stator downstream of the flow guides. These undulating seals can have a periodic waveform conformation. The undulating seals can create unsteadiness in the flow and recirculation of the leakage flow, which causes losses. The sealing system can also include other types of seals, such as labyrinth seals and brush seals, to further create a tortuous path for any leakage flow.

1 . A leakage flow control system for a turbine engine comprising:
 a turbine stator;   a turbine component rotatable about an axis of rotation;   a plurality of flow guides provided on the rotatable turbine component and being circumferentially arrayed thereabout, the flow guides being angled relative to the axis of rotation, the flow guides extending from the rotatable turbine component rotatable in a radially outward direction, whereby the flow guides increase tangential velocity on a leakage flow across an interface defined between the stator and the rotatable turbine component; and   an undulating seal operatively connected to stator and extending radially inward therefrom, the undulating seal further extending circumferentially about the stator so as to circumferentially surround at least a portion of the rotatable turbine component, the undulating seal being located axially downstream of the plurality of flow guides, whereby the undulating seal creates imbalances and recirculation in the leakage flow.   
   
   
       2 . The system of  claim 1  wherein the flow guides are airfoils. 
   
   
       3 . The system of  claim 1  wherein the undulating seal has one of a generally triangular waveform conformation and a generally sinusoidal conformation. 
   
   
       4 . The system of  claim 1  wherein the undulating seal has a substantially periodic waveform conformation. 
   
   
       5 . The system of  claim 1  further including a second undulating seal operatively connected to the stator and extending radially inward therefrom, wherein the second undulating seal extends circumferentially about the stator, wherein the second undulating seal is located axially downstream of the first undulating seal, whereby the undulating seal creates imbalances and recirculation in the leakage flow. 
   
   
       6 . The system of  claim 5  wherein the undulating seal and the second undulating seal are substantially identical. 
   
   
       7 . The system of  claim 1  wherein at least a portion of the stator surrounds the flow guides and includes a conical passage. 
   
   
       8 . The system of  claim 1  further including a forward cavity defined between the stator and the rotatable turbine engine component upstream of the flow guides and a cavity immediately downstream of the flow guides defined between the stator and the rotatable turbine engine component, wherein a passage extends through the stator so as to connect in fluid communication the forward cavity and the cavity downstream of the flow guides. 
   
   
       9 . The system of  claim 1  further including at least one of a labyrinth seal and a brush seal operatively connected to the stator. 
   
   
       10 . The system of  claim 1  wherein the stator is defined at least in part by a seal housing. 
   
   
       11 . A leakage flow control system for a turbine engine comprising:
 an first rotor disk having a generally axially downstream extending protrusion, the first rotor disk being rotatable about an axis of rotation;   a seal housing being spaced radially outward from the axially downstream extending protrusion of the rotor disk; and   a plurality of flow guides provided on the axially downstream extending protrusion and being circumferentially arrayed thereabout, the flow guides being angled relative to the axis of rotation, the flow guides extending from the axially downstream extending protrusion in a radially outward direction, whereby the flow guides increase tangential velocity on a leakage flow across an interface defined between the rotor disk and the seal housing.   
   
   
       12 . The system of  claim 11  wherein the flow guides are airfoils. 
   
   
       13 . The system of  claim 11  further including a first undulating seal operatively connected to seal housing and extending radially inward therefrom, wherein the first undulating seal extends circumferentially about the seal housing so as to circumferentially surround at least a portion of the axially downstream extending protrusion, wherein the first undulating seal is located axially downstream of the plurality of flow guides, whereby the first undulating seal creates imbalances and recirculation in the leakage flow across the interface. 
   
   
       14 . The system of  claim 13  wherein the first undulating seal has a substantially periodic waveform conformation. 
   
   
       15 . The system of  claim 14  further including a second undulating seal operatively connected to seal housing and extending radially inward therefrom, wherein the second undulating seal extends circumferentially about the seal housing, wherein the second undulating seal is located axially downstream of the first undulating seal, whereby the second undulating seal creates imbalances and recirculation in the leakage flow across the interface. 
   
   
       16 . The system of  claim 15  wherein the second undulating seal has a substantially periodic waveform conformation. 
   
   
       17 . The system of  claim 15  further including a second rotor disk having a generally axially upstream extending protrusion, wherein the second rotor disk is rotatable about an axis of rotation, wherein the second undulating seal circumferentially surrounds at least a portion of the axially upstream extending protrusion. 
   
   
       18 . The system of  claim 17  further including:
 a first seal operatively connected to the axially upstream extending protrusion of the second rotor disk in a region that is upstream of the second undulating seal; and   a second seal operatively connected to the axially upstream extending protrusion of the second rotor disk in a region that is downstream of the second undulating seal.   
   
   
       19 . The system of  claim 11  wherein a portion of the seal housing surrounds the flow guides and at least partially defines a conical passage, whereby the cross-sectional area of the interface decreases in the axial direction. 
   
   
       20 . The system of  claim 11  further including a forward cavity defined between the seal housing and the first rotor disk upstream of the flow guides and a cavity immediately downstream of the flow guides defined between the seal housing and the first rotor disk, wherein a passage extends through the seal housing so as to connect in fluid communication the forward cavity and the cavity downstream of the flow guides.