US Patent 10202865 Unducted thrust producing system

An unducted thrust producing system has a rotating element with an axis of rotation and a stationary element. The rotating element includes a plurality of blades each having a blade root proximal to the axis, a blade tip remote from the axis, and a blade span measured between the blade root and the blade tip. The rotating element has a load distribution such that at any location between the blade root and 30% span the value of ΔRCu in the air stream is greater than or equal to 60% of the peak ΔRCu in the air stream.