A centrifugal impeller for a turbomachine is provided. The centrifugal impeller comprises a plurality of aerodynamic vanes, each of the aerodynamic vanes having internal walls on which is associated a fabric element.

An insulated exhaust port liner of a cylinder head assembly for fluidly connecting to an internal combustion engine of a motor vehicle includes a sealing layer. The sealing layer has a first surface defining a passage for fluidly connecting to the internal combustion engine and receiving exhaust gas. The sealing layer further includes a second surface opposite to the first surface. The liner further includes a thermal barrier layer coated onto the second surface of the sealing layer. The thermal barrier layer is a porous non-woven material for supporting the sealing layer on the cylinder head and reducing a transfer of heat from the sealing layer to the cylinder head.

An insulated exhaust port liner of a cylinder head assembly for fluidly connecting to an internal combustion engine of a motor vehicle includes a sealing layer. The sealing layer has a first surface defining a passage for fluidly connecting to the internal combustion engine and receiving exhaust gas. The sealing layer further includes a second surface opposite to the first surface. The liner further includes a thermal barrier layer coated onto the second surface of the sealing layer. The thermal barrier layer is a porous non-woven material for supporting the sealing layer on the cylinder head and reducing a transfer of heat from the sealing layer to the cylinder head.