Abstract:
A variable vane assembly comprises an upstream vane stage including an airfoil coupled with an upstream vane stem and an upstream vane arm, configured to drive the upstream vane stem to rotate. The upstream vane stem is supported in an upstream housing boss. A downstream vane stage includes an airfoil coupled with a downstream vane stem and a downstream vane arm, and configured to drive the downstream vane stem to rotate. The downstream vane stem is supported in a downstream housing boss. A first clearance is defined between a radially inner end of the upstream vane arm and a radially outer end of the upstream housing boss. A second clearance is defined between a radially inner end of the downstream vane arm and a radially outer end of the downstream housing boss. A clearance ratio of the second clearance to the first clearance is greater than or equal to 10.
Abstract:
A disclosed gas turbine engine includes a case for a case for a compressor section including a bleed air slot. The bleed air slot includes an inlet having a first area radially inward of an outlet having a second area with the second area being greater than the first area. The bleed air slot further includes a center portion disposed along a radial line extending from an axis of the engine and an elongated portion extending from the opening at an angle relative to a line normal to the radial line.