LOW NOISE COMPRESSOR ROTOR FOR GEARED TURBOFAN ENGINE

摘要

A gear reduction effects a reduction in the speed of a fan relative to a speed of a low pressure turbine and a low pressure compressor portion. At least one of the low pressure turbine portion and low pressure compressor portion has a number of blades in each of a plurality of rows. The blades operate at least some of the time at a rotational speed. The number of blades and the rotational speed are such that the following formula holds true for at least one of the blade rows of the at least one of the low pressure turbine portion and/or the low pressure compressor sections: (number of blades x rotational speed)/60 ? 5500 Hz. The rotational speed is an approach speed in revolutions per minute.