Gas turbine engine with improved high pressure compressor leakage path guide structure

A gas turbine engine having an axial centerline, comprising:

• a compressor section having a high pressure compressor (HPC), wherein the HPC includes an HPC aft hub;
• a combustor section having a combustor;
• a turbine section;
• wherein a core gas path extends through the compressor section, the combustor section, and the turbine section;
• a tangential on board injector (TOBI) system that extends circumferentially around the engine axial centerline, the TOBI system having a plurality of nozzles and a TOBI inner radial flange;
• and
• an HPC leakage guide structure (LGS) having a LGS forward end and a LGS aft end, wherein the LGS forward end is disposed and configured to receive a leakage flow from the HPC and the LGS aft end is engaged with the TOBI inner radial flange;
• wherein the HPC leakage guide structure and the HPC aft hub are separated from one another and define an HPC aft hub cavity therebetween, wherein the HPC aft hub cavity extends between the LGS forward end and the LGS aft end,
• wherein the HPC aft hub cavity monotonically increases in a direction from the LGS forward end to the LGS aft end,
• wherein the HPC aft hub cavity monotonically increasing from the LGS forward end of the HPC leakage guide structure to a position where the LGS aft end and the TOBI inner radial flange engage, such that a radial height of the HPC aft hub cavity at the LGS forward end is less than a radial height of the HPC aft hub cavity at the position where the LGS aft end and the TOBI inner radial flange engage;
• and
• wherein the LGS aft end axially overlaps and is radially biased against the TOBI inner radial flange.