Transpirational cooling panel
A transpirational cooling panel comprises a porous ceramic matrix composite layer and a porous high-temperature fabric layer. A machined ceramic fiber batting is located between the porous ceramic matrix composite layer and the porous high-temperature fabric layer. A ceramic stitching joins the porous ceramic matrix composite layer and the porous high-temperature fabric layer through the machined ceramic fiber batting.
1 . A method of manufacturing a transpirational cooling panel, the method comprising
saturating one or more layers of a precursor ceramic fiber batting material with a polymer solution;
compressing the precursor ceramic fiber batting material comprising the polymer solution;
evaporating solvent from the precursor ceramic fiber batting material to form a ceramic batting/polymer intermediate;
machining the ceramic batting/polymer intermediate;
placing a ceramic fabric layer adjacent to the machined ceramic batting/polymer intermediate;
placing a porous high-temperature fabric layer adjacent to the machined ceramic batting/polymer intermediate on an opposite side of the machined ceramic batting/polymer intermediate as the ceramic fabric layer;
stitching the ceramic fabric layer to the porous high-temperature fabric layer through the machined ceramic batting/polymer intermediate using a ceramic thread to form a pre-panel structure;
heating the pre-panel structure to remove the polymer from within the machined ceramic batting/polymer intermediate after stitching the pre-panel structure;
forming a ceramic matrix composite skin that incorporates the ceramic fabric layer of the pre-panel structure, by
adding a solution comprising a suspension of ceramic particles and an organic component to the ceramic fabric layer of the pre-panel structure,
applying a first heating cycle to cure the organic component in the ceramic fabric layer, and
applying a second heating cycle to sinter the ceramic particles and to remove the organic component cured thereby forming pores in the ceramic matrix composite skin; and
coupling the porous high-temperature fabric layer to a carrier panel including one or more openings configured to pass cooling air.
2 . The method of claim 1 , wherein the polymer solution comprises an aqueous cellulosic polymer solution.
3 . The method of claim 2 , wherein the aqueous cellulosic polymer solution comprises methylcellulose.
4 . The method of claim 1 , wherein the ceramic fabric layer comprises one or more of aluminoborosilicate, alumina, or mullite.
5 . The method of claim 1 , wherein the porous high-temperature fabric layer comprises a glass fabric layer.
6 . The method of claim 1 , wherein the porous high-temperature fabric layer comprises one or more of E-glass or S-glass.
7 . The method of claim 1 , further comprising shaping the pre-panel structure with a mold after adding the solution to the ceramic fabric layer and before the first heating cycle.
8 . The method of claim 7 , wherein shaping the pre-panel structure with the mold comprises vacuum bag molding the pre-panel structure.
9 . The method of claim 1 , wherein the ceramic particles comprise particles of one or more of alumina, silica, or silicon carbide.
10 . The method of claim 1 , wherein machining the ceramic batting/polymer intermediate comprises smoothing a surface of the ceramic batting/polymer intermediate by milling.
11 . The method of claim 1 , wherein the precursor ceramic fiber batting material comprises one or more of alumina fibers, silica fibers, or mullite fibers.
12 . The method of claim 1 , wherein applying the second heating cycle to remove the organic component cured thereby forming the pores in the ceramic matrix composite skin comprises forming the pores with a void fraction in a range of 20-95% of the ceramic matrix composite skin.
13 . The method of claim 1 , further comprising incorporating the transpirational cooling panel into an exhaust system of an apparatus.