Hot gas intake scroll case assembly for aircraft engine

An aircraft engine comprising:

• a combustion engine having an exhaust, the combustion engine drivingly engaged to a load rotatable relative to a central axis;
• a turbine section in driving engagement with the load to compound power with the combustion engine;
• and
• a scroll case assembly fluidly interconnecting the exhaust of the combustion engine to the turbine section, the scroll case assembly comprising:
• an outer casting in the form of a shell extending in a non-axisymmetric fashion around the central axis and defining an inlet fluidly connected to the exhaust of the combustion engine;
• an inner casting axially inserted inside the outer casting to define therewith a conduit extending around the central axis from the inlet to an outlet fluidly connected to the turbine section of the aircraft engine, the inner casting having vanes circumferentially distributed around the central axis and projecting axially across the conduit from a front axially facing surface of the inner casting to a rear axially facing surface of the outer casting, the inner casting fastened to the outer casting via a first bolted joint interface at a front end of the scroll case assembly and a second bolted joint interface at a rear end of the scroll case assembly, the first bolted joint interface and the second bolted joint interface spaced radially from one another;
• wherein the second bolted joint interface includes a rear annular flange provided at a rear axially facing surface of the outer casting and respective distal ends of the vanes, the vanes individually bolted to the rear annular flange of the outer casting around the outlet of the conduit.

An aircraft engine comprising:

• a combustion engine having an exhaust, the combustion engine drivingly engaged to a load rotatable relative to a central axis;
• a turbine section in driving engagement with the load to compound power with the combustion engine;
• and
• a scroll case assembly fluidly interconnecting the exhaust of the combustion engine to the turbine section, the scroll case assembly comprising:
• an outer casting in the form of a shell extending in a non-axisymmetric fashion around the central axis and defining an inlet fluidly connected to the exhaust of the combustion engine;
• an inner casting axially inserted inside the outer casting to define therewith a conduit extending around the central axis from the inlet to an outlet fluidly connected to the turbine section of the aircraft engine, the inner casting having vanes circumferentially distributed around the central axis and projecting axially across the conduit from a front axially facing surface of the inner casting to a rear axially facing surface of the outer casting, the inner casting fastened to the outer casting via a first bolted joint interface at a front end of the scroll case assembly and a second bolted joint interface at a rear end of the scroll case assembly, the first bolted joint interface and the second bolted joint interface spaced radially from one another;
• wherein the first bolted joint interface comprises a front annular flange projecting radially outwardly from an outer diameter surface of a front projection at a front end of the outer casting, and a corresponding front annular flange projecting radially outwardly front an outer diameter surface at a front end of the inner casting, the outer diameter surface at the front end of the inner casting sized to fit inside the front projection of the outer casting.