Westinghouse Electric

About: Westinghouse Electric is a company organization based out in Cranberry Township, Pennsylvania, United States. It is known for research contribution in the topics: Brake & Circuit breaker. The organization has 27959 authors who have published 38036 publications receiving 523387 citations.

An efficient procedure for modeling complex hysteresis processes in ferromagnetic materials

Abstract: A simple mathematical formalism for describing arbitrary hysteresis processes is presented. The information required to apply this formalism to a given magnetic material can be obtained with relatively little effort from experimental hysteresis curves such as normal loops or, in special cases, from just the initial curve. The basic physical model is that of Preisach. A more convenient, less widely known, treatment of this modes by Everett to which we have applied magnetic symmetry constraints leads to a succinct description of hysteresis processes. We have applied this procedure to calculate losses in nonoriented electrical steel laminations. The fully non-linear electromagnetic field equations were solved on the computer for this simple geometry with no restrictions on the hysteresis paths. The calculated losses agreed at the 5% level with experimental losses for a wide range of frequencies and inductions.

Luminescence of Donor-Acceptor Pairs in Cubic SiC

Abstract: The photoluminescence of donor-acceptor pairs, under laser excitation, was recorded at 1.8\ifmmode^\circ\else\textdegree\fi{}K. The spectrum is type II, and is attributed to N-Al pairs. Well-resolved lines were identified up to the 80th shell, and the van der Waals and multiple interactions were evaluated, following procedures used for the very similar GaP pair spectra. The limiting photon energy for distant pairs is $h{\ensuremath{ u}}_{\ensuremath{\infty}}=2.0934$ eV. As in some GaP spectra, intensity anomalies were observed. With the GaP work serving as a guide, one intensity anomaly was interpreted as a channel cutoff, another as a phonon resonance. This permitted us to evaluate the ionization energies, ${E}_{D}=118$ meV for N, and ${E}_{A}=(179 \mathrm{meV})+{E}_{x}$ for Al, with ${E}_{x}$ the still unknown exciton binding energy. With lower resolution the maximum and the half-width of the spectrum envelope were measured as a function of excitation intensity, and phonon replicas were recorded. The band maximum at low excitation yields an impurity level of 1.6\ifmmode\times\else\texttimes\fi{}${10}^{18}$ ${\mathrm{cm}}^{\ensuremath{-}3}$.

Gas turbine vane with a cooled inner shroud

Abstract: A gas turbine vane (17) having an inner shroud (26) that is cooled by a portion of the cooling air directed to a cavity (45) between two adjacent rows of discs (55, 56). A portion of the cooling air in the cavity flows through impingement plates (83, 84) and impinges on the inner (98) surface of the inner shroud (26). Another portion of the cooling air flows through a passage (88) in the leading edge (42) of the inner shroud that has a pin fin (89) array for enhanced cooling. The impingement plates form chambers that collect both the impingement air and the pin fin passage air and direct it through holes (92) in the trailing edge (43) of the inner shroud for cooling of the trailing edge. Longitudinal passages (93, 94) along the side of the inner shroud direct the cooling air from the pin fin passage to the trailing edge (43).

Turbine blades made from multiple single crystal cast superalloy segments

Abstract: Large gas turbine blades (10) made from separate cast segments (12, 14. 16, 18) of superalloys are disclosed. The turbine blade is designed such that bond lines between adjacent segments are placed in low stress regions of the blade. The cast superalloy segments of the blades are aligned and fitted together with specified tolerances. The turbine blade segments are then joined by transient liquid phase bonding, followed by a controlled heat treatment which produces the desired microstructure in the bond region. The method allows for the production of large, high quality turbine blades (10) by joining small, high quality cast superalloy sections (12, 14, 16, 18), in comparison with prior attempts to cast large turbine blades as single pieces which have produced very low yields and high individual component costs.