Patent ID: 8632301

Claim:
A gas turbine engine comprising: a fan, a compressor section having a low pressure portion and a high pressure portion, a combustor section, and a turbine having a low pressure portion, the low pressure turbine portion driving said low pressure compressor portion and the fan; a gear reduction effecting a reduction in the speed of said fan relative to a speed of the low pressure turbine and the low pressure compressor portion; at least one of said low pressure turbine portion and said low pressure compressor portion having a number of blades in each of a plurality of rows, and said blades operating at least some of the time at a rotational speed, and said number of blades and said rotational speed being such that the following formula holds true for at least one of the blade rows of said at least one of the low pressure turbine portion and/or the low pressure compressor sections: (number of blades×rotational speed)/60≧5500; and said rotational speed being an approach speed in revolutions per minute.