Patent application number | Description | Published |
20090212504 | HIGH TEMPERATURE SEAL FOR A TURBINE ENGINE - A turbine includes a static member, a moveable member fluidly connected to the static member, and a flexible seal. The flexible seal includes a spring component having a base section mounted to one of the static member and the moveable member of the turbine and a plurality of biasing members. Each of the plurality of biasing members includes a first portion extending from the base section and a cantilevered portion. The flexible seal further includes a seal component provided on the cantilevered portion of each of the plurality of biasing members. The seal component is biased into contact with the other of the static member and the moveable member. | 08-27-2009 |
20100058766 | Segmented Combustor Cap - A combustor cap is cooperable with an impingement plate in a turbine fuel nozzle and includes a plurality of cap segments independently securable to the impingement plate. The plurality of cap segments are radially and tangentially movable relative to the impingement plate. | 03-11-2010 |
20100115953 | Integrated Combustor and Stage 1 Nozzle in a Gas Turbine and Method - An integrated combustor and stage one nozzle in a gas turbine includes a combustion chamber that receives premixed fuel and air from at least one fuel nozzle group at separate axial locations. The combustion chamber includes a liner and a transition piece that deliver hot combustion gas to the turbine. The stage one nozzle, the liner and the transition piece are integrated into a single part. At least one of the axial locations of the one or more fuel nozzle groups includes a plurality of small scale mixing devices that concentrate heat release and reduce flame length. | 05-13-2010 |
20100170258 | COOLING APPARATUS FOR COMBUSTOR TRANSITION PIECE - Disclosed is an apparatus for cooling a single-piece duct includes at least one metal wrapper disposed at the transition piece located outboard of the transition piece. At least one support boss is located between the metal wrapper and the transition piece. The support boss, the metal wrapper and transition piece define at least one cooling flow channel for directing flow for cooling the transition piece. A related method of cooling a single-piece duct extending between a forward end of a combustor and a first stage of a turbine includes providing a plurality of flow direction devices radially between the single-piece duct and a metal wrapper extending at least partially around the single-piece duct; flowing cooling air into a space between the single-piece duct and the metal wrapper such that the plurality of flow direction devices guide the cooling air about a surface of the single-piece duct enclosed by the metal wrapper. | 07-08-2010 |
20100205972 | ONE-PIECE CAN COMBUSTOR WITH HEAT TRANSFER SURFACE ENHACEMENTS - A method, system, and apparatus is provided for transferring heat from a can combustor associated with a gas turbine by providing a one-piece can combustor body having surface features that facilitate the transfer of heat away from the can combustor body, and by directing air flow to the surface features so that heat from the can combustor body is transferred from the surface features to the air flow. | 08-19-2010 |
20100218502 | EFFUSION COOLED ONE-PIECE CAN COMBUSTOR - A combustor for an industrial turbine includes a single transition piece transitioning directly from a combustor head-end to a turbine inlet. The transition piece includes an inner surface and an outer surface. The inner surface bounds an interior space for combusted gas flow from the combustor head-end to the turbine inlet. The outer surface at least partially defines an area for compressor discharge air flow. The transition piece includes a plurality of apertures configured to allow compressor discharge air flow into the interior space. Each of the plurality of apertures extends from an entry portion on the outer surface to an exit portion on the inner surface. | 09-02-2010 |
20100236249 | Systems and Methods for Reintroducing Gas Turbine Combustion Bypass Flow - A system and method for reintroducing gas turbine combustion bypass flow. The system may include a combustor body, wherein the combustor body includes a reaction zone for primary combustion of fuel and air, and a casing enclosing the combustor body and defining an annular passageway for carrying compressor discharge air into the combustor body at one end. The system further may include a reintroduction manifold for receiving combustor bypass air extracted from the compressor discharge air in the annular passageway, and one or more reintroduction slots in communication with the reintroduction manifold for injecting the combustor bypass air into the combustor body downstream of the reaction zone. The method may include extracting combustor bypass air from the annular passageway, transporting the combustor bypass air to a reintroduction manifold, and reintroducing the combustor bypass air into the combustor body through one or more reintroduction slots in communication with the reintroduction manifold. | 09-23-2010 |
20100257863 | COMBINED CONVECTION/EFFUSION COOLED ONE-PIECE CAN COMBUSTOR - An industrial turbine engine comprises a combustion section, an air discharge section downstream of the combustion section, a transition region between the combustion and air discharge section, a combustion transition piece and a sleeve. The transition piece defines an interior space for combusted gas flow. The sleeve surrounds the combustor transition piece so as to form a flow annulus between the sleeve and the transition piece. The sleeve includes a first set of apertures for directing cooling air from compressor discharge air into the flow annulus. The transition piece includes an outer surface bounding the flow annulus and an inner surface bounding the interior surface, and includes a second set of apertures for directing cooling air in the flow annulus to the interior space. Each of the second set of apertures extends from an entry portion on the outer surface to an exit portion on the inner surface. | 10-14-2010 |
20100287943 | METHODS AND SYSTEMS FOR INDUCING COMBUSTION DYNAMICS - Methods and systems are provided for inducing combustion dynamics within turbine engines to remove combustion deposits within the turbine engine during operation of the turbine engine. | 11-18-2010 |
20100293955 | MULTI-PREMIXER FUEL NOZZLE SUPPORT SYSTEM - A system comprising a fuel nozzle. The fuel nozzle includes a mounting base and an inlet flow conditioner extending directly from the mounting base in a downstream direction. Moreover, the inlet flow conditioner structurally supports the fuel nozzle without a central support member extending directly from the mounting base inside the inlet flow conditioner. | 11-25-2010 |
20100300106 | SYSTEM AND METHOD FOR THERMAL CONTROL IN A CAP OF A GAS TURBINE COMBUSTOR - A system comprises a turbine combustor cap. The turbine combustor cap includes a plurality of segments. Each segment of the plurality of segments has edges abutting at least two fuel nozzle receptacles. Moreover, each segment of the plurality of segments does not completely surrounding any one fuel nozzle receptacle. | 12-02-2010 |
20110014029 | SEALS FOR A TURBINE ENGINE, AND METHODS OF ASSEMBLING A TURBINE ENGINE - A side seal for sealing the side edges of adjacent combustors of a turbine engine include extended ends. The extended ends of the side seal abut and seal against inner and outer circumferential seals to prevent leakage of combustion gases. | 01-20-2011 |
20110107769 | IMPINGEMENT INSERT FOR A TURBOMACHINE INJECTOR - A turbomachine includes a compressor, a turbine operatively coupled to the compressor, and a combustion assembly fluidly linking the compressor and the turbine. The combustion assembly includes at least one injector having a burner tube including an outer wall portion and an inner wall portion that define a mixing zone. A swirler arranged within the mixing zone. The swirler includes a plurality of vanes, with at least one of the plurality of vanes having a wall section including an outer surface and an inner surface that define a hollow interior portion. An insert member is arranged within the hollow interior portion. The insert member includes at least one guide element that is disposed and configured to deliver a fluid flow to the hollow interior portion to flow over the wall section of the at least one of the plurality of vanes. | 05-12-2011 |
20110217159 | PREFERENTIAL COOLING OF GAS TURBINE NOZZLES - Turbine nozzle assemblies include a plurality of circumferentially spaced first components and second components, which are designed to provide different amounts of cooling. The second components, which are generally aligned with an opening of transition pieces, are designed to provide more cooling than the first components, which are generally aligned with interfaces between the transition pieces. | 09-08-2011 |
20110239652 | SEGMENTED ANNULAR RING-MANIFOLD QUATERNARY FUEL DISTRIBUTOR - A combustor section is provided and includes a segmented annular manifold mounted upstream from a fuel nozzle support in a section of a passage through which an oxidizer flows, each segment of the manifold being substantially axially aligned and including a body to accommodate fuel internally that is formed to define injection holes through which the fuel is injected into the passage through which the oxidizer flows upstream of the fuel nozzle support. | 10-06-2011 |
20110247341 | COMBUSTOR LINER HELICAL COOLING APPARATUS - A combustor liner is provided. The combustor liner may include an upstream portion and a downstream end portion. The upstream portion may have a radius and a length along a generally longitudinal axis. The downstream end portion may have a radius and a length along the generally longitudinal axis. The downstream end portion may define a plurality of channels. Each of the plurality of channels may extend helically through the length of the downstream end portion. Each of the plurality of channels may be configured to flow an air flow therethrough, cooling the downstream end portion. | 10-13-2011 |
20110304104 | SPRING LOADED SEAL ASSEMBLY FOR TURBINES - A spring loaded seal assembly is disclosed for sealing a gap between adjacent turbine components. The seal assembly may generally include a turbine seal and a spring member. The turbine seal may extend between the adjacent turbine components and may be configured to seal the gap defined between the turbine components. The spring member may be configured to engage the turbine seal so as to maintain the seal in sealing engagement with the adjacent turbine components. | 12-15-2011 |
20110314825 | GAS TURBINE SYSTEM HAVING PREMIXED INJECTOR VANES - In certain exemplary embodiments, a system includes an annular duct having an inner annular wall and an outer annular wall. The system also includes a plurality of injector vanes configured to mix air and fuel to produce an air-fuel mixture, and configured to inject the air-fuel mixture into a central chamber between the inner and outer annular walls. | 12-29-2011 |
20120031097 | MULTI-PREMIXER FUEL NOZZLE - The present application provides a fuel nozzle for use in a gas turbine. The fuel nozzle may include a mounting flange, a number of premixers attached to each other, and a number of gas pathways extending from the mounting flange to the number of premixers. | 02-09-2012 |
20120210720 | COMBUSTOR ASSEMBLY FOR USE IN A TURBINE ENGINE AND METHODS OF FABRICATING SAME - A combustor assembly that includes a casing that includes a plenum, a combustor liner positioned within the plenum and defining a combustion chamber there within, and a transition piece that includes a forward portion that is coupled to the combustion liner and an aft portion that extends from the forward portion. The aft portion includes a transition piece frame. The transition piece frame includes an upstream surface, a downstream surface, and a radially inner surface extending between the upstream and downstream surfaces. The radially inner surface includes a leading edge that extends between the radially inner surface and the upstream surface. A plurality of first cooling passages extend from the upstream surface to the downstream surface. Each of the first cooling passages is oriented obliquely with respect to the leading edge from the upstream surface towards the downstream surface. | 08-23-2012 |
20120234018 | AFT FRAME AND METHOD FOR COOLING AFT FRAME - An aft frame and a method for cooling an aft frame are disclosed. In one embodiment, an aft frame for a transition piece in a combustor is disclosed. The combustor includes the transition piece and an impingement sleeve at least partially defining a flow path therebetween. The aft frame includes a body and a generally radially extending cooling passage defined in the body, the cooling passage comprising a first end configured to accept a coolant. The aft frame further includes an exhaust passage defined in the body, the exhaust passage including a first end in communication with the cooling passage and a second end configured for communication with the flow path for flowing the coolant therethrough. | 09-20-2012 |
20120304653 | LOAD MEMBER FOR TRANSITION DUCT IN TURBINE SYSTEM - A loading assembly for a turbine system is disclosed. The loading assembly includes a transition duct and a load member. The transition duct extends between a fuel nozzle and a turbine section, and has an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The load member extends from the transition duct and is configured to transfer a load between the transition duct and an adjacent transition duct along at least one of the longitudinal axis, the radial axis, or the tangential axis. | 12-06-2012 |
20120304656 | COMBUSTION LINER AND TRANSITION PIECE - An apparatus is disclosed. The apparatus may include a body configured to flow hot gases of combustion between a forward end and an aft end. Additionally, the body may include a plurality of raised sections spaced apart circumferentially around an outer perimeter of the body. The raised sections may generally extend lengthwise between the forward and aft ends. | 12-06-2012 |
20120304665 | MOUNT DEVICE FOR TRANSITION DUCT IN TURBINE SYSTEM - A mount device and mounting assembly for a turbine system are disclosed. The mounting assembly includes a transition duct extending between a fuel nozzle and a turbine section. The transition duct has an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The mounting assembly further includes a mount device connecting the transition duct to the turbine section. The mount device is configured to allow movement of the outlet about at least two axes. | 12-06-2012 |
20120324897 | METHODS AND SYSTEMS FOR TRANSFERRING HEAT FROM A TRANSITION NOZZLE - Methods and systems are provided for transferring heat from a transition nozzle. The transition nozzle includes a transition portion, a nozzle portion integrally formed with the transition portion, and at least one surface feature configured to transfer heat away from the transition portion and/or the nozzle portion. The transition portion is oriented to channel the combustion gases towards the nozzle portion. | 12-27-2012 |
20120324898 | COMBUSTOR ASSEMBLY FOR USE IN A TURBINE ENGINE AND METHODS OF ASSEMBLING SAME - A combustor assembly for use with a turbine engine that includes a rotor assembly. The combustor assembly includes a casing that includes a plenum and a combustor liner that is spaced a distance from the plenum and that defines a combustion chamber therein. A transition nozzle extends between the combustor liner and the rotor assembly for channeling combustion gases from the combustion chamber to the rotor assembly. The transition nozzle includes a transition portion and a nozzle portion integrally formed with the transition portion. An annular flowsleeve is coupled radially outward from the transition nozzle such that an annular flow path is defined between the flowsleeve and the transition nozzle. The flowsleeve includes a plurality of openings extending through an outer surface of the flowsleeve for providing flow communication between the plenum and the annular flow path to facilitate impingement cooling of the flowsleeve. | 12-27-2012 |
20120328421 | METHODS AND SYSTEMS FOR COOLING A TRANSITION NOZZLE - A turbine assembly includes a fuel nozzle configured to mix fuel and air and a transition nozzle oriented to receive the fuel and air mixture from the fuel nozzle. The transition nozzle includes a transition portion and a nozzle portion integrally formed with the transition portion. The transition nozzle includes a plurality of openings oriented to channel air to facilitate cooling the transition portion and/or the nozzle portion. The transition portion is oriented to channel combustion gases towards the nozzle portion. | 12-27-2012 |
20130008177 | SUPPORT ASSEMBLY FOR TRANSITION DUCT IN TURBINE SYSTEM - A support assembly for a turbine system is disclosed. The support assembly includes a transition duct extending between a fuel nozzle and a turbine section. The transition duct has an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis. The support assembly further includes a plurality of protrusions extending from the transition duct. The plurality of protrusions are configured to allow movement of the transition duct about at least one axis. | 01-10-2013 |
20130008178 | SUPPORT ASSEMBLY FOR TRANSITION DUCT IN TURBINE SYSTEM - A support assembly for a turbine system is disclosed. The support assembly includes a transition duct extending between a fuel nozzle and a turbine section. The transition duct has an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis. The support assembly further includes an annular contact member extending from the transition duct. The contact member is configured to allow movement of the transition duct about at least one axis. | 01-10-2013 |
20130086914 | TURBINE SYSTEM - A turbine system is disclosed. The turbine system includes a transition duct having an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The turbine system further includes a turbine section connected to the transition duct. The turbine section includes a plurality of shroud blocks at least partially defining a hot gas path, a plurality of buckets at least partially disposed in the hot gas path, and a plurality of nozzles at least partially disposed in the hot gas path. At least one of a shroud block, a bucket, or a nozzle includes means for withstanding high temperatures. | 04-11-2013 |
20130111911 | LEAF SEAL FOR TRANSITION DUCT IN TURBINE SYSTEM - A turbine system is disclosed. In one embodiment, the turbine system includes a transition duct. The transition duct includes an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The transition duct further includes an interface member for interfacing with a turbine section. The turbine system further includes a leaf seal contacting the interface member to provide a seal between the interface member and the turbine section. | 05-09-2013 |
20130111912 | FLEXIBLE METALLIC SEAL FOR TRANSITION DUCT IN TURBINE SYSTEM - A turbine system is disclosed. In one embodiment, the turbine system includes a transition duct. The transition duct includes an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The transition duct further includes an interface member for interfacing with a turbine section. The turbine system further includes a flexible metallic seal contacting the interface member to provide a seal between the interface member and the turbine section. | 05-09-2013 |
20130115048 | CONVOLUTION SEAL FOR TRANSITION DUCT IN TURBINE SYSTEM - A turbine system is disclosed. In one embodiment, the turbine system includes a transition duct. The transition duct includes an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The transition duct further includes an interface member for interfacing with a turbine section. The turbine system further includes a convolution seal contacting the interface member to provide a seal between the interface member and the turbine section. | 05-09-2013 |
20130167543 | METHODS AND SYSTEMS FOR COOLING A TRANSITION NOZZLE - A transition nozzle for use with a turbine assembly is provided. The transition nozzle includes a liner defining a combustion chamber therein, a wrapper circumscribing the liner such that a cooling duct is defined between the wrapper and the liner, a cooling fluid inlet configured to supply a cooling fluid to the cooling duct, and a plurality of ribs coupled between the liner and the wrapper such that a plurality of cooling channels are defined in the cooling duct. | 07-04-2013 |
20130181413 | SPRING LOADED SEAL ASSEMBLY FOR TURBINES - A spring loaded seal assembly is disclosed for sealing a gap between adjacent turbine components. The seal assembly may generally include a turbine seal and a spring member. The turbine seal may extend between the adjacent turbine components and may be configured to seal the gap defined between the turbine components. The spring member may be configured to engage the turbine seal so as to maintain the seal in sealing engagement with the adjacent turbine components. | 07-18-2013 |
20130255262 | Combustor with Non-Circular Head End - The present application provides a combustor for use with a gas turbine engine. The combustor may include a head end with a non-circular configuration, a number of fuel nozzles positioned about the head end, and a transition piece extending downstream of the head end. | 10-03-2013 |
20130255266 | Transition Nozzle Combustion System - The present application provides a combustion system for use with a cooling flow. The combustion system may include a head end, an aft end, a transition nozzle extending from the head end to the aft end, and an impingement sleeve surrounding the transition nozzle. The impingement sleeve may define a first cavity in communication with the head end for a first portion of the cooling flow and a second cavity in communication with the aft end for a second portion of the cooling flow. The transition nozzle may include a number of cooling holes thereon in communication with the second portion of the cooling flow. | 10-03-2013 |
20130276451 | COMBUSTION SYSTEM INCLUDING A TRANSITION PIECE AND METHOD OF FORMING USING A CAST SUPERALLOY - A combustion system including a transition piece and method of forming the transition piece using a cast nickel-based superalloy is provided. The transition piece includes a body defining a flowpath and enclosure, the body having a circular inlet section for receiving combustion product from the combustor and an outlet end for flowing the combustor products into a first stage nozzle of a gas turbine. The transition piece comprises a one-piece single casting construction of the circular inlet section, the body, and the outlet end. The transition piece is formed from a nickel-based superalloy. The transition piece has a thick-to-thin ratio of wall thickness of thick transition to wall thickness of thin transition of about 1.1 to about 2.5. | 10-24-2013 |
20130283802 | COMBUSTOR - A combustor includes an end cap that extends radially across at least a portion of the combustor, wherein the end cap comprises an upstream surface axially separated from a downstream surface. A shroud circumferentially surrounds at least a portion of the end cap, wherein the shroud at least partially defines a fuel plenum between the upstream surface and the downstream surface. A combustion chamber downstream from the end cap defines a longitudinal axis. A plurality of tubes extend from the upstream surface through the downstream surface of the end cap to provide fluid communication through the end cap to the combustion chamber. A transition duct circumferentially surrounds at least a portion of the combustion chamber downstream from the end cap and curves tangentially from the longitudinal axis. | 10-31-2013 |
20130283804 | TRANSITION DUCT WITH LATE INJECTION IN TURBINE SYSTEM - A system for supplying an injection fluid to a combustor is disclosed. The system includes a transition duct comprising an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The passage defines a combustion chamber. The system further includes a tube providing fluid communication for the injection fluid to flow through the transition duct and into the combustion chamber. | 10-31-2013 |
20130283817 | FLEXIBLE SEAL FOR TRANSITION DUCT IN TURBINE SYSTEM - A turbine system is disclosed. In one embodiment, the turbine system includes a transition duct. The transition duct includes an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The transition duct further includes an interface feature for interfacing with an adjacent transition duct. The turbine system further includes a flexible seal contacting the interface feature to provide a seal between the interface feature and the adjacent transition duct. The flexible seal includes a sheet having a first surface, an opposing second surface, and a peripheral edge therebetween. | 10-31-2013 |
20130283818 | CONVOLUTION SEAL FOR TRANSITION DUCT IN TURBINE SYSTEM - A turbine system is disclosed. In one embodiment, the turbine system includes a transition duct. The transition duct includes an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The transition duct further includes an interface feature for interfacing with an adjacent transition duct. The turbine system further includes a convolution seal contacting the interface feature to provide a seal between the interface feature and the adjacent transition duct. | 10-31-2013 |
20140000263 | MULTI-PREMIXER FUEL NOZZLE SUPPORT SYSTEM | 01-02-2014 |
20140123652 | GAS TURBINE BURNER - A gas turbine includes a compressor and at least one combustor downstream from the compressor. The combustor includes a burner having an inner shroud extending axially along at least a portion of the burner, an outer shroud radially separated from the inner shroud and extending axially along at least a portion of the burner, and a plurality of stator vanes extending radially between the inner shroud and the outer shroud. The stator vanes have an inner end proximate the inner shroud and an outer end proximate the outer shroud. The burner further includes a vortex tip at one of either the inner end or the outer end of the stator vanes. The vortex tip provides a gap between the inner end and the inner shroud or the outer end and the outer shroud, and the vortex tip includes a plurality of fuel ports. The gas turbine further includes a turbine downstream from the combustor. | 05-08-2014 |
20140150434 | FUEL NOZZLE FOR A COMBUSTOR OF A GAS TURBINE ENGINE - A fuel nozzle for a gas turbine generally includes a main body having an upstream end axially separated from a downstream end. The main body at least partially defines a fuel supply passage that extends through the upstream end and at least partially through the main body. A fuel distribution manifold is disposed at the downstream end of the main body. The fuel distribution manifold includes a plurality of axially extending passages that extend through the fuel distribution manifold. A plurality of fuel injection ports defines a flow path between the fuel supply passage and each of the plurality of axially extending passages. | 06-05-2014 |
20140283520 | TRANSITION DUCT WITH IMPROVED COOLING IN TURBOMACHINE - Turbine systems are provided. In one embodiment, a turbine system includes a transition duct comprising an inlet, an outlet, and a duct passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The duct passage includes an upstream portion extending from the inlet and a downstream portion extending from the outlet. The turbine system further includes a rib extending from an outer surface of the duct passage, the rib dividing the upstream portion and the downstream portion. | 09-25-2014 |