30,182 research outputs found
Performance of single-stage axial-flow transonic compressor with rotor and stator aspect ratios of 1.19 and 1.26 respectively, and with design pressure ratio of 2.05
The overall and blade-element performances of a low-aspect-ratio transonic compressor stage are presented over the stable operating flow range for speeds from 50 to 100 percent of design. At design speed the rotor and stage achieved peak efficiencies of 0.876 and 0.840 at pressure ratios of 2.056 and 2.000, respectively. The stage stall margin at design speed was 10 percent
Performance of single-stage axial-flow transonic compressor with rotor and stator aspect ratios of 1.19 and 1.26, respectively, and with design pressure ratio of 1.82
The overall and blade-element performance of a low-aspect-ratio transonic compressor stage is presented over the stable operating flow range at 70, 90, and 100 percent design speeds. At design speed the rotor and stage achieved peak efficiencies of 0.872 and 0.845 at pressure ratios of 1.875 and 1.842, respectively. The stage stall margin at design speed was 21.8 percent
Performance of single-stage axial-flow transonic compressor with rotor and stator aspect ratios of 1.63 and 1.78, respectively, and with design pressure ratio of 1.82
The overall and blade-element performance of a transonic compressor stage is presented over the stable operating flow range for speeds from 50 to 100 percent of design. The stage was designed for a pressure ratio of 1.82 at a flow 20.2 kg/sec and a tip speed of 455 m/sec. At design speed the stage achieved a peak efficiency of 0.821 at a pressure ratio of 1.817. The stage stall margin at design speed based on conditions at stall and peak efficiency was about 11 percent
Design and overall performance of four highly loaded, high speed inlet stages for an advanced high-pressure-ratio core compressor
The detailed design and overall performances of four inlet stages for an advanced core compressor are presented. These four stages represent two levels of design total pressure ratio (1.82 and 2.05), two levels of rotor aspect ratio (1.19 and 1.63), and two levels of stator aspect ratio (1.26 and 1.78). The individual stages were tested over the stable operating flow range at 70, 90, and 100 percent of design speeds. The performances of the low aspect ratio configurations were substantially better than those of the high aspect ratio configurations. The two low aspect ratio configurations achieved peak efficiencies of 0.876 and 0.872 and corresponding stage efficiencies of 0.845 and 0.840. The high aspect ratio configurations achieved peak ratio efficiencies of 0.851 and 0.849 and corresponding stage efficiencies of 0.821 and 0.831
Performance of single-stage axial-flow transonic compressor with rotor and stator aspect ratios of 1.63 and 1.77, respectively, and with design pressure ratio of 2.05
The overall and blade-element performance of a transonic compressor stage is presented over the stable operating range for speeds from 50 to 100 percent of design. The stage was designed for a pressure ratio of 2.05 at a flow of 20.2 kg/sec and a tip speed of 455 m/sec. At design speed the rotor and stage achieved peak efficiencies of 0.849 and 0.831, respectively, at the minimum flow condition. The stage stall point occurred at a flow higher than the design flow
Performance of a transonic compressor rotor with an aspect ratio of 6.5
The overall and blade-element performances and the aerodynamic design parameters of a transonic rotor with an aspect ratio of 6.5, designed to investigate the effects of aspect ratio on range and performance are presented. The rotor was designed for a total-pressure ratio of 1.53, an efficiency of 0.898, and a weight flow of 67.76 pounds per second
The supersymmetric Penrose transform in six dimensions
We give a supersymmetric extension to the six-dimensional Penrose transform
and give an integral formula for the on-shell (0, 2) supermultiplet. The
relationship between super fields on space-time and twistor space is clarified
and the space-time superfield constraint equations are derived from the
geometry of supertwistor space. We also explain the extension to more general
(0,n) supermultiplets and give twistor actions for these theories.Comment: 20 page
5-micron photometry of late-type dwarfs
We present narrowband-M photometry of nine low-mass dwarfs with spectral
types ranging from M2.5 to L0.5. Combining the (L'-M') colours derived from our
observations with data from the literature, we find colours consistent with a
Rayleigh-Jeans flux distribution for spectral types earlier than M5, but
enhanced F_3.8/F_4.7 flux ratios (negative (L'-M') colours) at later spectral
types. This probably reflects increased absorption at M' due to the CO
fundamental band. We compare our results against recent model predictions and
briefly discuss the implications.Comment: accepted for the Astronomical Journa
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