Abstract: A turbine blade that may include an airfoil and a blade dovetail, the blade dovetail being shaped corresponding to a dovetail slot in a turbine disk. The blade dovetail may include a dovetail backcut sized and positioned according to blade geometry to maximize a balance between stress reduction on the disk, stress reduction on the blade, a useful life of the turbine blade, and maintaining or improving the aeromechanical behavior of the turbine blade. A start point of the dovetail backcut, which defines a length of the dovetail backcut along a dovetail axis, may be determined relative to a datum line positioned a fixed distance from a forward face of the blade dovetail along a centerline of the dovetail axis. The start point of the dovetail backcut may be at least approximately 1.539 inches in an aft direction from the datum line.

Abstract: A turbine blade that may include an airfoil and a blade dovetail, the blade dovetail being shaped corresponding to a dovetail slot in a turbine disk. The blade dovetail may include a dovetail backcut sized and positioned according to blade geometry to maximize a balance between stress reduction on the disk, stress reduction on the blade, a useful life of the turbine blade, and maintaining or improving the aeromechanical behavior of the turbine blade. A start point of the dovetail backcut, which defines a length of the dovetail backcut along a dovetail axis, may be determined relative to a datum line positioned a fixed distance from a forward face of the blade dovetail along a centerline of the dovetail axis. The start point of the dovetail backcut may be at least approximately 1.645 inches in an aft direction from the datum line.

Abstract: An impingement box for a turbine shroud. The impingement box may include a first side with an air access aperture positioned therein and a second side with a number of impingement holes positioned therein. The second side may be positioned a predetermined distance above a floor of the shroud such that the impingement holes provide a cooling flow to the floor of the shroud.

Abstract: The present invention relates to an encoding method processing video object planes (VOPs) of I, P or B type and including a dynamic allocation of said VOPs. According to said method, for each input frame a preliminary forward motion estimation is carried out between current and previous frames. Current and previous motion fields are then used to evaluate a coherence factor, expressed as connected to the sums of local differences within current and previous motion field. According to the value of the coherence factor with respect to an empirically determined threshold, a decision is finally taken on the type of the frame to be coded.

Abstract: Blade load path on a gas turbine disk can be diverted to provide a significant disk fatigue life benefit. A plurality of gas turbine blades are attachable to a gas turbine disk, where each of the gas turbine blades includes a blade dovetail engageable in a correspondingly-shaped dovetail slot in the gas turbine disk. In order to reduce gas turbine disk stress, an optimal material removal area is defined according to blade and/or disk geometry to maximize a balance between stress reduction on the gas turbine disk, a useful life of the gas turbine blade, and maintaining or improving the aeromechanical behavior of the gas turbine blade. Removing material from the material removal area effects the maximized balance.

Abstract: The present invention relates to an encoding method processing video object planes (VOPs) of I, P or B type and including a dynamic allocation of said VOPs. According to said method, for each input frame a preliminary forward motion estimation is carried out between current and previous frames. Current and previous motion fields are then used to evaluate a coherence factor, expressed as connected to the sums of local differences within current and previous motion field. According to the value of the coherence factor with respect to an empirically determined threshold, a decision is finally taken on the type of the frame to be coded.

Abstract: The invention relates to encoding of an input sequence of digital images delivering a base and an enhancement layer bitstream for transmission of video data in real time over a fluctuating-rate transmission channel. The method distributes the encoded data for the images of said sequence between two subsequences of base and an enhancement layer and evaluates degree of occupation of two associated buffers. A notional (virtual, dummy) bi-directional image is created in one of the subsequences which is intended to receive stuffing data, when the degree of occupation on the buffer associated with said subsequences isbelow a predetermined threshold. This method enables the adding of stuffing data in a case not provided for by the MPEG-4 standard, for example, for a sequence encoded in the rectangular mode and having no (regularly coded) bi-directional images (B-frames).

Abstract: A turbine bucket airfoil has a conical fillet about the intersection of the airfoil tip and tip shroud having a nominal profile in accordance with coordinate values of X and Y, offset 1, offset 2 and Rho set forth in Table I. The shape parameters of offset 1, offset 2 and Rho define the configuration of the fillet at the specified X and Y locations about the fillet to provide a fillet configuration accommodating high localized stresses. The fillet shape may be parabolic, elliptical or hyperbolic as a function of the value of the shape parameter ratio of D1 D1 + D2 at each X, Y location where D1 is a distance between an intermediate point along a chord between edge points determined by offsets O1 and O2 and a shoulder point on the fillet surface and D2 is a distance between the shoulder point and an apex location at the intersection of the airfoil tip and tip shroud.

Abstract: Third stage turbine buckets have airfoil profiles substantially in accordance with Cartesian coordinate values of X, Y and Z set forth Table I wherein X and Y values are in inches and the Z values are non-dimensional values from 0.03 span to 0.95 span convertible to Z distances in inches by multiplying the Z values by the height of the airfoil in inches. The X and Y values are distances which, when connected by smooth continuing arcs, define airfoil profile sections at each distance Z. The profile sections at each distance Z are joined smoothly to one another to form the bucket airfoil shape. The X, Y and Z distances may be scalable as a function of the same constant or number to provide a scaled up or scaled down airfoil section for the bucket. The nominal airfoil given by the X, Y and Z distances lies within an envelop of ±0.150 inches in directions normal to the surface of the airfoil.

Abstract: A turbine bucket includes a bucket airfoil having a tip shroud with leading and trailing edges defining leading and trailing edge profiles substantially in accordance with Cartesian coordinate values of X and Y at points 12-20 and 1-11, respectively, set forth in Table I. The X and Y values are distances in inches which, when respective points 12-20 and 1-11 are connected by smooth, continuing arcs, define the leading and trailing edge tip shroud profiles. An airfoil profile at 95% span is defined by Cartesian coordinate values of X, Y and Z in Table II having the same X, Y origin along the radial Z axis as the origin of Table I. The profiled leading and trailing edges of the tip shroud relative to the airfoil profile afford optimum tip shroud mass distribution which maximizes creep life of the bucket. Stage efficiency is also improved by providing a tip shroud covering the airfoil throat.

Abstract: The MPEG-4 standard describes four prediction modes: a direct prediction mode, a bidirectional prediction mode, a forward prediction mode, and a backward prediction mode. These modes may be used for the encoding of a block on the basis of a past reference frame and a future reference frame. Thus, for the encoding of a given block, the invention provides an advantageous strategy leading to the choice of a well adapted prediction mode among the four possible ones. The proposed strategy works in favor of the direct mode and gives criteria to be satisfied when using this particular prediction mode.

Abstract: In the Improved PB-frames mode, one of the options of the H.263+ Recommendation, a macroblock of a B-frame may be encoded according to a forward, a backward or a bidirectional prediction mode. The invention relates to a method of encoding a sequence of pictures defining a strategy for the choice of a prediction mode among the three possible ones in the encoding of B-macroblock. This strategy is based upon SAD(Sum of Absolute Difference) calculations and motion vectors coherence and allows to use backward prediction when scene cuts occur. In the proposed strategy, the SAD of the bidirectional prediction is not necessarily derived when the motion is non linear allowing less calculation and reduction in CPU burden. The invention also relates to an encoding system for carrying out said method and including a computer-readable medium storing instructions that allow the implementation of this method.

Abstract: In the Improved PB-frames mode, one of the options of the H.263+ Recommendation, a macroblock of a B-frame may be encoded according to a forward, a backward or a bidirectional prediction mode. The invention relates to a method of encoding a sequence of pictures defining a strategy for the choice of a prediction mode among the three possible ones in the encoding of B-macroblock. This strategy is based upon SAD(Sum of Absolute Difference) calculations and motion vectors coherence and allows to use backward prediction when scene cuts occur. The calculations are here performed on original pictures allowing less calculation and reduction in CPU burden. The invention also relates to an encoding system for carrying out said method and including a computer-readable medium storing instructions that allow the implementation of this method.