Stepped heat shield for a turbine engine combustor
An assembly is provided for a turbine engine. This turbine engine assembly includes a combustor wall with a shell and a heat shield. The combustor wall defines a quench aperture therethrough. The combustor wall also defines a cavity between the shell and the heat shield. The shell defines a first aperture through which air is directed into the cavity. The heat shield includes a rail that at least partially defines a second aperture configured to direct at least some of the air within the cavity out of the combustor wall and towards the quench aperture.
1. An assembly for a turbine engine, the assembly comprising:
a combustor wall extending along an axial centerline, the combustor wall including a shell and a heat shield, and the combustor wall defining a quench aperture therethrough and defining a cavity between the shell and the heat shield;
the shell defining a first aperture through which air is directed into the cavity;
the heat shield including a rail that contacts the shell and that at least partially defines a second aperture configured to direct at least some of the air within the cavity out of the combustor wall and towards the quench aperture, wherein the second aperture comprises a slot which extends axially along the axial centerline through the rail, and the slot comprises a circumferentially elongated slot;
the heat shield including an upstream surface and a downstream surface that form a boundary of a combustion chamber;
an upstream edge of the downstream surface is radially displaced, in a direction towards the shell, from a downstream edge of the upstream surface;
wherein the heat shield includes a first panel adjacent a second panel;
the first panel includes the rail and the upstream surface, and the rail is at a downstream end of the first panel and is disposed upstream of the downstream edge of the upstream surface to define an open cavity at the downstream end of the first panel to direct the at least some of the air within the cavity out of the combustor wall and towards the quench aperture;
the second panel includes the downstream surface; and
the quench aperture extends through the second panel.
2. The assembly of claim 1 , wherein the heat shield has a stepped configuration.
3. The assembly of claim 1 , wherein the quench aperture extends vertically through the combustor wall; and adjacent ends of the first and the second panels are vertically displaced from one another.
4. The assembly of claim 1 , wherein
the heat shield includes a base configured as an arcuate plate; and
the rail extends between the base and the shell.
5. The assembly of claim 1 , wherein the rail is configured such that the air directed through the second aperture forms an air blanket against the heat shield that flows towards a region of the heat shield at the quench aperture.
6. The assembly of claim 1 , wherein the axial centerline is substantially parallel to a portion of the heat shield through which the slot extends.
7. The assembly of claim 1 , wherein the slot is one of a plurality of slots through which at least some of the air within the cavity is directed out of the combustor wall and towards the quench aperture, and wherein each of the plurality of slots extends axially along the axial centerline through the rail.
8. The assembly of claim 1 , wherein the first aperture comprises an impingement aperture through which the air is directed into the cavity to impinge against the heat shield.
9. The assembly of claim 1 , wherein the heat shield defines an effusion aperture through which some of the air within the cavity is directed out of the combustor wall.
10. An assembly for a turbine engine, the assembly comprising:
a combustor wall extending along an axial centerline, the combustor wall including a shell and a heat shield, and the combustor wall defining a quench aperture through and a cavity between the shell and the heat shield;
the shell configured to direct air into the cavity;
the heat shield having a stepped configuration with a riser portion extending between an upstream run portion and a downstream run portion such that an upstream edge of the downstream run portion is disposed a radial distance radially outboard of a downstream edge of the upstream run portion; and
the riser portion configured to direct at least some of the air within the cavity out of the combustor wall and towards the quench aperture;
wherein the riser portion at least partially defines a slot through which the at least some of the air within the cavity is directed out of the combustor wall, and the slot extends radially within the riser portion; and
wherein the riser portion comprises a rail that projects out from a base of the upstream run portion of the heat shield at a downstream end of the upstream run portion and upstream of the downstream edge of the upstream run portion to define an open cavity at a downstream end of the upstream run portion for directing the at least some of the air within the cavity out of the combustor wall and towards the quench aperture, the rail having a distal end that contacts the shell;
wherein the slot extends radially within and axially through the rail.
11. The assembly of claim 10 , wherein the slot comprises a circumferentially elongated slot that extends axially through and circumferentially within the riser portion.
12. The assembly of claim 10 , wherein the riser portion at least partially defines a plurality of slots through which the at least some of the air within the cavity is directed out of the combustor wall, and each of the plurality of slots extends radially within and axially through the riser portion and the rail.
13. The assembly of claim 10 , wherein the heat shield includes
an upstream panel that defines the upstream run portion and the riser portion, and includes the rail and the base; and
a downstream panel that defines the downstream run portion.
14. The assembly of claim 10 , wherein the upstream run portion is configured to direct some of the air within the cavity out of the combustor wall.
15. An assembly for a turbine engine, the assembly comprising:
a combustor wall extending along an axial centerline, the combustor wall including and defining a cavity between a shell and a heat shield;
the shell configured to direct air into the cavity;
the heat shield having a stepped configuration with a riser portion extending radially between an upstream run portion and a downstream run portion such that at least an upstream end of the downstream run portion is radially recessed into the combustor wall from a downstream end of the upstream run portion;
the riser portion configured to direct some of the air within the cavity out of the combustor wall to film cool the downstream run portion; and
the upstream run portion configured to direct some of the air within the cavity to effuse out of the combustor wall;
wherein the riser portion is configured with a plurality of slots formed in a rail through which the some of the air within the cavity is directed out of the combustor wall, and wherein a circumferentially adjacent pair of the plurality of slots each extends axially through the rail along the axial centerline, the rail extending from the heat shield to the shell at the downstream end of the upstream run portion and upstream of a downstream edge of the upstream run portion, thereby defining an open cavity at the downstream end of the upstream run portion;
wherein the combustor wall defines a quench aperture through the shell and the downstream run portion, and the riser portion is configured to use the plurality of slots and the open cavity to direct the air within the cavity out of the combustor wall toward the quench aperture.
16. The assembly of claim 15 , wherein the upstream run portion is configured with a plurality of effusions apertures.