Additively manufactured combustion chambers, manifold structures and hybrid additive processes related thereto
Additively manufactured thrust chambers and thrust chambers with integral fluid manifolds, and hybrid additive manufacturing methods for their production, are provided. Hybrid additive manufacturing techniques may combine a variety of processes including, WAAM, PBF, cold spray and DED, for example, to produce objects with variant dimensional requirements, i.e., large overall size and small features. Hybrid additive manufacturing may be defined as provide various process layers within any manufactured object. These process layers in turn allow for the introduction of variable feature and size distribution throughout the manufactured object. Hybrid process layers according to aspects may also allow the use of a variety of materials or may use a single material across the various process layers.
1 . A hybrid additive manufacturing method for forming a thermal combustion chamber comprising:
powder bed fusion forming an integral regeneratively-cooled liner body of a first material, having an inner wall defining an open-ended combustion chamber volume, an outer wall having at least one set of inlets and at least one set of outlets disposed at different heights along a length thereof, and a plurality of cooling channels formed between the inner and outer walls and in fluid communication with the at least one set of inlets and at least one set of outlets;
wire arc additive manufacturing, directed energy deposition, or cold spray additive manufacturing forming at least one structural cladding region of a second material, integral with and extending around a perimeter of the liner body over at least a portion of the outer wall adjacent to or overlapping the at least one set of inlets and at least one set of outlets;
wire arc additive manufacturing or directed energy deposition forming at least one separate fluid manifold formed of a third material and disposed in association with and in fluid communication with each of the at least one set of inlets and the at least one set of outlets, each of the separate fluid manifolds being integral with the at least one structural cladding region and comprising:
first and second base structures, wherein each of the first and second base structures comprises a plurality of tapered stepped layers such that each of the first and second base structures narrow from a first end proximal to the structural cladding to a second end distal to the structural cladding, wherein the first and second base structures are integral with the at least one structural cladding region and extend around the perimeter of the liner body on opposing sides of the at least one set of inlets or at least one set of outlets, and
an upper wall integral with the second ends of and spanning between the first and second base structures such that the first and second base structures and the upper wall form a fluid manifold enclosure extending around the perimeter of the liner body over the associated at least one set of inlets and at least one set of outlets,
wherein the fluid manifold enclosure of each fluid manifold defines a fluid manifold outer wall and inner fluid conduit and are configured such that the inner fluid conduit has a generally cylindrical fluid manifold cross-section;
wire arc additive manufacturing or directed energy deposition forming at least one fluid access port integrally disposed in each of the fluid manifold outer walls and having connection elements disposed thereon such that each of the at least one fluid access port allows for external fluid communication to one of the fluid manifolds; and
wherein the at least one separate fluid manifold, at least one fluid access port, at least one set of inlets, at least one set of outlets, and cooling channels of the liner body define a single fluid flow path therebetween having a termination at an upper end of the thermal combustion chamber.
2 . The method of claim 1 , wherein the cooling channels have a dimensional resolution of less than 0.05 mm.
3 . The method of claim 1 , wherein, of the first material, the second material and the third material, at least two are distinct.
4 . The method of claim 3 , wherein at least one of the at least two distinct materials comprises a Cu-based alloy or a Ni—Cr-based alloy.
5 . The method of claim 1 , further comprising forming at least one feature integrally formed or interconnected on or within the structure of the liner body, the structural cladding and/or the fluid manifold.
6 . The method of claim 5 , wherein the forming the at least one feature is performed using wire arc additive manufacturing or directed energy deposition.
7 . The method of claim 5 , wherein the at least one feature comprises a flange, a separate fluid manifold, a fuel injection manifold, or a thrust skirt.
8 . The method of claim 7 , wherein the at least one feature comprises the thrust skirt, and the method further comprises powder bed fusion, wire arc additive manufacturing, or directed energy deposition forming the thrust skirt integral with or interconnected with a second open end of the thermal combustion chamber volume and defining a generally open conical inner volume wherein a circumference of the conical inner volume expands distal to the thermal combustion chamber.
9 . The method of claim 8 , wherein the thrust skirt further comprises inner and outer walls, and a plurality of cooling channels formed therebetween, the plurality of cooling channels in fluid communication with the cooling channels of the regeneratively-cooled liner body.
10 . The method of claim 9 , wherein the thrust skirt further comprises:
a set of fluid inlets disposed in an outer surface thereof at a first end thereof proximal to the thermal combustion chamber;
a set of fluid outlets disposed in an outer surface thereof at a second end thereof distal to the thermal combustion chamber,
wherein the set of fluid inlets and outlets are in fluid communication with the plurality of cooling channels disposed within the thrust skirt,
wherein separate integral fluid manifolds are formed on the outer surface and around the perimeter of the thrust skirt to enclose each of the set of fluid inlets and outlets, and are in fluid communication with separate fluid manifolds on the thrust combustion chamber, and
wherein the separate integral fluid manifolds are formed using wire arc additive manufacturing or directed energy deposition.
11 . The method of claim 10 , further comprising wire arc additive manufacturing or directed energy deposition forming at least one integration feature integrally on at least one element selected from the group consisting of: the structural cladding region, the at least one fluid manifold, and the at least one fluid access port.