Method of fabricating a shape memory alloy damped structure

#The present invention relates to the cooling and damping of rotor blades and stationary vanes (both of which are generically referred to herein as “blades” unless otherwise indicated). The invention relates more particularly to cooling and damping of blades using a coolant supplied to internal channels in the blades that are lined with a shape memory alloy, or superelastic alloy (both of which are hereinafter generally referred to as a “shape memory alloy”).

#Compressors and turbines are examples of the turbo-machinery that include a number of rotor blades that are driven in a rotational sense by a gas passing therethrough. For example, a turbine produces rotational power by receiving high-temperature, high-pressure gases such as combustion gases from a fuel combustor, and expanding the gases to a lower temperature and lower pressure via an alternating series of stationary vanes and rotating blades. A gas turbine may have a single “stage” consisting of a row of stationary vanes followed by a row of rotor blades, or it may have two or more such stages in series.

#In high-performance gas turbine engines, the temperature of the combustion gases entering the first stage of the turbine typically is so high that the available materials for constructing the stationary vanes and rotor blades are not capable of withstanding the extreme temperature without some type of active cooling of the blades and vanes. Thus, modern advances in gas turbine technology have largely been made through discoveries of improved materials capable of withstanding higher temperatures, coupled with improved cooling schemes. These cooling schemes have included film cooling techniques and the circulation of coolant through internal passages defined by a turbine blade as described in more detail by U.S. patent application Ser. No. 10/029,451 entitled Fluid-Cooled Turbine Blades by James Lobitz, et al. filed Dec. 19, 2001; the contents of which are incorporated herein in their entirety.

#Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

#FIG. 1 is a schematic perspective view of a turbine rotor blade in accordance with one embodiment of the present invention;

#FIG. 2 is a schematic cross-sectional view of a blade in accordance with one embodiment of the present invention;

#The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.

#With reference to FIGS. 1-3, blade 10 in accordance with one preferred embodiment of the invention is shown in schematic representation. For purposes of example, a turbine rotor blade will be hereinafter described. However, the blade of the present invention may be utilized by other turbo-machinery, such as compressors, that would benefit from the reduction in blade vibration and/or an increase in blade cooling. Moreover, the turbines, compressors or other turbo-machinery that include blades according to the present invention may be utilized in various industries, including the turbines and compressors utilized in power generation facilities, chemical manufacturing facilities, and in aircraft and rocket engines to name a few.

#The blade 10 generally includes a blade airfoil portion and a blade root portion 14. The blade airfoil portion comprises a structural member 12 that substantially defines the airfoil shape of the blade, and whose primary function is to withstand the various loads exerted on the blade during use and to maintain structural integrity of the blade. As shown in FIG. 1, the blade structural member extends along a blade longitudinal axis 16 from an inner end 12a to an opposed outer end, or tip, 12b, with the generally airfoil-shape being defined in cross-section normal to the blade longitudinal axis. The structural member is accordingly formed of any of various conventional materials used for forming turbine rotor blades, including but not limited to aluminum, nickel-based superalloys and others. The inner end of the structural member is attached to the blade root that serves to affix the rotor blade in a turbine disk. The blade root and the structural member can comprise a monolithic structure formed from a single piece of material, or can comprise two separately formed members that are subsequently joined.