Rotor with flattened exit pressure profile

摘要

A rotor blade comprises an airfoil extending radially from a root section to a tip section and axially from a leading edge to a trailing edge, the leading and trailing edges defining a curvature therebetween. The curvature determines a relative exit angle at a relative span height between the root section and the tip section, based on an incident flow velocity at the leading edge of the airfoil and a rotational velocity at the relative span height. In operation of the rotor blade, the relative exit angle determines a substantially flat exit pressure ratio profile for relative span heights from 75% to 95%, wherein the exit pressure ratio profile is constant within a tolerance of 10% of a maximum value of the exit pressure ratio profile.

主权项

1. A rotor blade comprising:
a leading edge, a trailing edge, a root section and a tip section; and an airfoil extending radially from the root section to the tip section and axially from the leading edge to the trailing edge, the leading and trailing edges defining a curvature therebetween; wherein, in operation of the rotor blade, the curvature determines a relative exit angle at a span height between the root section and the tip section, based on an incident flow velocity at the leading edge of the airfoil and a rotational velocity at the relative span height; wherein, in operation of the rotor blade, the relative exit angle determines an exit pressure ratio profile that is substantially constant for relative span heights from 75% to 95%, within a tolerance of 10% (±10%) of a maximum value of the exit pressure ratio profile; and wherein the relative exit angle is defined according to angle β2 or angle β2′ as set forth in Table 1 herein for relative span heights from 75% to 95%, within a tolerance of two degrees (±2°).