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Volume 30, Issue 12
Displaying 1-7 of 7 articles from this issue
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Satoshi OGATA2002 Volume 30 Issue 12 Pages 709-714
Published: December 10, 2002
Released on J-STAGE: July 11, 2011
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Yoshio KODAMA, Makoto HATAKEYAMA, Souichi SASAKI2002 Volume 30 Issue 12 Pages 715-723
Published: December 10, 2002
Released on J-STAGE: July 11, 2011
JOURNAL FREE ACCESSThe effects of three parameters; the location of the partition of impeller, the bare ratio and the outlet angle of scroll casing on the turbulent noise and aerodynamic characteristics, were experimentally investigated in the dual-cascades centrifugal fans. In this report, we proposed a new method to estimate the wake width which is an important parameter to calculate the turbulent noise. It was shown that the fan noise became lower when the bare ratio was from 9% to 25% and the outlet angle of scroll casing was about 20°. When the inlet/outlet area ratio of upper cascade was equal to that of the lower cascade and both of these are equal to about unity, the fan noise became lower. The predicted sound pressure level agrees well with the experimental values of the overall turbulent noise with L-weighting and A-weighting functions.View full abstractDownload PDF (3437K) -
Hiroaki HASEGAWA, Tadahiko FUJINAGA, Tadayuki HANADA, Katsuhiko TAKITA2002 Volume 30 Issue 12 Pages 724-732
Published: December 10, 2002
Released on J-STAGE: July 11, 2011
JOURNAL FREE ACCESSRequirements for increased power output and improved fuel economy demand higher turbine inlet temperature for gas turbine engines. The application of ceramic components in turbine material enables higher turbine operatingtemperature with no cooling techniques. However, the ceramic materials have several unfavorable properties, such as thebrittleness, the low reliability of the ceramic parts. In this study, the ceramic turbine wheel which had a tip diameter greaterthan 200mm was developed for the aircraft gas turbine engine. The design of ceramic turbine components is influenced by thecharacteristic material properties of ceramic. The rotational rig test was carried out and the engine test was demonstratedunder full load operating conditions. The successful testing of the ceramic turbine components in the aircraft gas turbineengine has been accomplished. The test results indicate that the ceramic turbine is capable of operating under the actual usecondition of the aircraft ceramic turbine engine.View full abstractDownload PDF (10376K) -
Hidechito HAYASHI, Yoshio KODAMA, Shinichirou FUCHIGAMI, Tohru FUKANO2002 Volume 30 Issue 12 Pages 733-740
Published: December 10, 2002
Released on J-STAGE: July 11, 2011
JOURNAL FREE ACCESSDiscrete frequency noise (DFN) generated from a tubular centrifugal fan was investigated experimentally and theoretically. It was made clear that the DFN is caused by the interaction of the rotor blades with the distorted inlet flow, but not with the stator blades. It is effective for reducing the DFN level that the inlet nozzle is lengthened to the duct diameter and set the honeycomb in it. In the latter case, the DFN level can be reduced almost to the turbulent noise level. The DFN level was theoretically predicted. The prediction shows that the noise source concentrates to the leading edge of the blade. And the characteristic lengths are almost constant for any inlet distortion. The predicted noise level agrees with the experimental results.View full abstractDownload PDF (1037K) -
Ikuo ISHIDA2002 Volume 30 Issue 12 Pages 741-746
Published: December 10, 2002
Released on J-STAGE: July 11, 2011
JOURNAL FREE ACCESSDownload PDF (3164K) -
[in Japanese]2002 Volume 30 Issue 12 Pages 747-753
Published: December 10, 2002
Released on J-STAGE: July 11, 2011
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[in Japanese]2002 Volume 30 Issue 12 Pages 754-759
Published: December 10, 2002
Released on J-STAGE: July 11, 2011
JOURNAL FREE ACCESSDownload PDF (7507K)
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