Inter-turbine ducts with flow control mechanisms

A turbine section of a gas turbine engine, the turbine section being annular about a longitudinal axis, the turbine section comprising:

• a first turbine with a first inlet and a first outlet;
• a second turbine with a second inlet and a second outlet;
• an inter-turbine duct extending from the first outlet to the second inlet and configured to direct an air flow from the first turbine to the second turbine, the inter-turbine duct being defined by a hub and a shroud;
• and
• at least a first splitter blade disposed within the inter-turbine duct so as to be positioned between the hub and the shroud, the first splitter blade comprising a pressure side facing the shroud, a suction side facing the hub, and at least one vortex generating structure having a leading end opposite a trailing end positioned on the suction side that extends in a radial direction from a surface of the suction side toward the hub, the at least one vortex generating structure having a height that increases from the leading end to the trailing end.