Abstract: A heat exchanger for use as a condensing heat exchanger in a gas-fired hot air furnace has a ceramic pipe forming an initial portion of a fluid flow path through the heat exchanger. The ceramic pipe receives the combustion gases from a primary heat exchanger and reduces the temperature of the combustion gases to below a certain temperature. A polymer-based structure is connected to the ceramic pipe and forms the remaining portion of the fluid flow path through the heat exchanger. The geometry and orientation of the ceramic pipe is selected so that the certain temperature of the combustion gases exiting the ceramic pipe is less than the softening temperature of the polymer-based structure. The resultant heat exchanger combines the high temperature and corrosion resistance of ceramic materials with the low cost and high corrosion resistance of polymer materials.

Abstract: An engineered ceramic component for the leading edge of a rotor blade provides enhanced erosion protection therefor. In one embodiment, the engineered ceramic component includes a strain isolator member, an aerodynamic ceramic member, a first adhesive bond layer, and a second adhesive bond layer. The strain isolator member, which is operative to minimize strain transfer between the rotor blade infrastructure and the aerodynamic ceramic member, is configured so that inner mold line surface thereof is complementary to outer mold line surface of the rotor blade infrastructure. The aerodynamic ceramic member, which is operative to provide enhanced erosion protection for the respective leading edge of the rotor blade, is configured so that the outer mold line surface thereof defines the aerodynamic configuration of the respective leading edge and the inner mold line surface is complementary to the outer mold line surface of the strain isolator member.

Abstract: A method of joining adjacent, non-coplanar, fiber reinforced composite structures includes machining a plurality of serrations (4) into an edge (6) of a consolidated first fiber reinforced composite structure (2) such that reinforcing fibers continue from a main body (14) of the first fiber reinforced composite structure (2) into the serrations (4). One or more reinforcing fiber plies (16) are then laid up around the serrations (4) to form an unconsolidated second structure such that the serrations (4) protrude through at least one reinforcing fiber ply (16). In addition to the one or more reinforcing fiber plies (16), the unconsolidated second structure also includes a matrix precursor. Sufficient heat and pressure are applied to the unconsolidated second structure and the serrations (4) to consolidate the second structure into a fiber reinforced composite structure (8).

Abstract: A method of joining adjacent, non-coplanar, fiber reinforced composite structures includes machining a plurality of serrations (4) into an edge (6) of a consolidated first fiber reinforced composite structure (2) such that reinforcing fibers continue from a main body (14) of the first fiber reinforced composite structure (2) into the serrations (4). One or more reinforcing fiber plies (16) are then laid up around the serrations (4) to form an unconsolidated second structure such that the serrations (4) protrude through at least one reinforcing fiber ply (16). In addition to the one or more reinforcing fiber plies (16), the unconsolidated second structure also includes a matrix precursor. Sufficient heat and pressure are applied to the unconsolidated second structure and the serrations (4) to consolidate the second structure into a fiber reinforced composite structure (8).

Abstract: A heating unit (14) includes a flame holder (2) that has a plurality of randomly distributed pores and comprises at least about 50 wt % ceramic particles that have an emissivity of at least about 0.7. The heating unit (14) also has means for conveying a fuel/air mixture to the flame holder (2), means (18) for igniting the fuel/air mixture so it forms a flame in proximity to the flame holder, means (20) for transferring heat from the flame to a heat transfer medium, and means (26) for exhausting combustion products from the heating unit. A fuel/air mixture may be directed through the flame holder (2) and burned to form a flame in proximity to the flame holder such that the flame and flame holder interact to produce emissions of less than about 10 ng/J NO.sub.x.