CONVERTIBLE VGV TO SQUARE BASE/RING STATOR VANE
Publication Date: 2013-Jun-06
The IP.com Prior Art Database
Multistage variable guide vanes (VGVs) are necessary to reduce the effect of rotational stall in a gas turbine engine compressor. A new design of stator turbine blade arrangement within the compressor casing is disclosed in which VGV and "fixed" vane use the same airfoil and same casing. The problem of retuning of the airfoil based on "fixed" attachment scheme has been eliminated by this new design. The tuning slot base can be variously configured in square or tapered shapes for vibration matching.
This publication deals with convertible variable guide vanes (VGV) to square base/ring stator vane of a gas turbine engine’s compressor. There is a need for multistage VGVs not only to mitigate rotating stall but from a general performance and operability standpoint. During the rig/engine testing, the goal is to optimize the VGV schedules and simultaneously understand the sensitivity of the compressor to "fixing" the stators (usually aft stage VGVs) to determine the need for variable stagger. Because of the aggressive schedule between the rig and engine, we need to consider maximizing rig test flexibility (and ultimately the compressor optimization) with the engine cost. An airfoil diffuser which is of three dimensional shape with a varying solidity in the span wise direction is known as variable stagger. This publication involves design of one or more aft stage VGVs along with the compressor case so, if not needed, the VGV can be removed and a fixed stage of stator vanes (ring or square base) can be incorporated into the engine bill of materials without major design changes.
BRIEF DESCRIPTION OF THE DRAWINGS
Convertible VGV to square base/ring stator vane is disclosed with reference to the drawings, in which
FIGURE 1 shows arrangement for mounting VGV and fixed vanes to stator casing
FIGURE 2 shows configuration of tuning slot base for frequency matching, A) taper configuration and B) square base configuration
Airfoil with modified/truncated VGV features (button, spindle) fits into square base or ring segment which mates with casing is disclosed, as shown in Figures 1 and 2....