Low noise turbine for geared gas turbine engine

A gas turbine engine comprising:

• a propulsor section including a propulsor having a plurality of propulsor blades;
• a turbine section including a first turbine and a second turbine;
• a compressor section driven by the turbine section, the compressor section including a first compressor and a second compressor;
• a geared architecture driven by the first turbine;
• a first shaft that connects an input of the geared architecture to the first turbine;
• a second shaft that connects the second compressor and the second turbine, and wherein the first and second shafts are concentric and are rotatable via bearing systems about an engine axis;
• wherein the propulsor is driven by the first turbine via the geared architecture, and the second turbine drives the second compressor;
• wherein at least one stage of the turbine section includes an array of rotatable blades and an array of vanes, and the array of vanes of the at least one stage are immediately upstream or downstream from the array of blades;
• wherein a ratio of the number of vanes to the number of blades of the at least one stage is greater than or equal to 1.55;
• wherein a mechanical tip rotational Mach number of the array of blades is greater than or equal to 0.5 at an approach speed, the approach speed taken at an approach certification point as defined in Part 36 of the Federal Airworthiness Regulation;
• and
• wherein the gas turbine engine is rated to produce 15,000 pounds of thrust or more.