An assembly for a gas turbine engine comprising: a housing having a housing cavity , an inlet , and an outlet ; a rotatable shaft positioned proximate the outlet ; a seal positioned at an interface of the rotatable shaft and the housing, wherein the seal comprises: porous material adjacent the shaft and the housing ; and a shell substantially separating the porous material from the housing cavity , the shell comprising: an inlet that allows fluid flow from the housing cavity to the porous material; and an outlet that allows fluid flow from the porous material to the housing interior, and characterized in that the inlet is positioned radially inward of the outlet , and wherein the shell is substantially annular, having a radially inner edge abutting the shaft , and wherein the shell further comprises: a first radial surface extending substantially radially outward from the radially inner edge with respect to a centerline axis of the shaft, wherein the inlet is one of a plurality of holes extending through the first radial surface . a housing having a housing cavity , an inlet , and an outlet ; a rotatable shaft positioned proximate the outlet ; a seal positioned at an interface of the rotatable shaft and the housing, wherein the seal comprises: porous material adjacent the shaft and the housing ; and a shell substantially separating the porous material from the housing cavity , the shell comprising: an inlet that allows fluid flow from the housing cavity to the porous material; and an outlet that allows fluid flow from the porous material to the housing interior, and characterized in that the inlet is positioned radially inward of the outlet , and wherein the shell is substantially annular, having a radially inner edge abutting the shaft , and wherein the shell further comprises: a first radial surface extending substantially radially outward from the radially inner edge with respect to a centerline axis of the shaft, wherein the inlet is one of a plurality of holes extending through the first radial surface . porous material adjacent the shaft and the housing ; and a shell substantially separating the porous material from the housing cavity , the shell comprising: an inlet that allows fluid flow from the housing cavity to the porous material; and an outlet that allows fluid flow from the porous material to the housing interior, and characterized in that the inlet is positioned radially inward of the outlet , and wherein the shell is substantially annular, having a radially inner edge abutting the shaft , and wherein the shell further comprises: a first radial surface extending substantially radially outward from the radially inner edge with respect to a centerline axis of the shaft, wherein the inlet is one of a plurality of holes extending through the first radial surface . an inlet that allows fluid flow from the housing cavity to the porous material; and an outlet that allows fluid flow from the porous material to the housing interior, and characterized in that the inlet is positioned radially inward of the outlet , and wherein the shell is substantially annular, having a radially inner edge abutting the shaft , and wherein the shell further comprises: a first radial surface extending substantially radially outward from the radially inner edge with respect to a centerline axis of the shaft, wherein the inlet is one of a plurality of holes extending through the first radial surface . <EOS>