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Volume 40, Issue 12
Displaying 1-5 of 5 articles from this issue
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Technical papers
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（1st Report：Identification of Important Design Parameters by Using QFD Method）Junya TAKIDA, Masaru FUKUOKA, Maro KUNIEDA, Ken-ichi FUNAZAKI, Masahar ...Article type: Technical papers
2012 Volume 40 Issue 12 Pages 705-714
Published: 2012
Released on J-STAGE: April 09, 2015
JOURNAL FREE ACCESSAn application of the QFD method for the design of rocket turbopump turbines is presented. Generally, rocket turbopump turbines are designed as supersonic impulse turbines, and because of their special specifications, improvements in turbine efficiency and robustness are difficult. Further improvement in turbine design techniques is needed because turbine performance directly affects engine performance and reliability in a liquid rocket propulsion system. In this study, QFD is positioned as a means for selecting the design parameters in the parametric design process. Therefore, the purpose of QFD is to visualize the voice of the market(market needs)，which are essential for parametric design of supersonic turbines to identify important design parameters. In this paper, the QFD results for the identification of important design parameters and for the visualization of the market needs which was obtained from rocket engine stakeholders are discussed.View full abstractDownload PDF (295K) -
Koichi YONEZAWA, Daisuke KONISHI, Kazuyoshi MIYAGAWA, Peter DOERFLER, ...Article type: Technical papers
2012 Volume 40 Issue 12 Pages 715-724
Published: 2012
Released on J-STAGE: April 09, 2015
JOURNAL FREE ACCESSModel tests and CFD were carried out to find out the cause of cavitation surge in hydraulic power plants. In experiments the cavitation surge was observed at flow rates higher and lower than the swirl free flow rate, both with and without a surge tank placed just upstream of the inlet volute. An unsteady CFD was carried out with two boundary conditions：(1)the flow rate is fixed to be constant at the inlet volute, (2)the total pressure is kept constant at the volute inlet, corresponding to the experiments without/with the surge tank. The surge was observed with both boundary conditions at both higher and lower flow rates. Discussions as to the cause of the surge are made based on additional tests with an orifice at the diffuser exit, and with the diffuser replaced with a straight pipe.View full abstractDownload PDF (227K) -
Yoshinobu TSUJIMOTO, Hiroshi TANAKA, Peter DOERFLER, Koichi YONEZAWA, ...Article type: Technical papers
2012 Volume 40 Issue 12 Pages 725-734
Published: 2012
Released on J-STAGE: April 09, 2015
JOURNAL FREE ACCESSThe effects of acoustic resonance and volute geometry on phase resonance are studied theoretically and experimentally using a centrifugal fan. One dimensional theoretical model is developed taking account of the reflection from the discharge pipe end. It was found that the phase resonance occurs, even with the effects of acoustic resonance, when the rotational speed of rotor-stator interaction pattern agrees with the sound velocity. This was confirmed by experiments with and without a silencer at the discharge pipe exit. The pressure wave measurements showed that there are certain effects of the crosssectional area change of the volute which is neglected in the one dimensional model. To clarify the effects of area change, experiments were carried out by using a ring volute with a constant area.View full abstractDownload PDF (281K) -
Koichi YONEZAWA, Jun AONO, Donghyuk KANG, Hironori HORIGUCHI, Yutaka K ...Article type: Technical papers
2012 Volume 40 Issue 12 Pages 735-744
Published: 2012
Released on J-STAGE: April 09, 2015
JOURNAL FREE ACCESSThe transfer matrix and unsteady cavitation characteristics, cavitation compliance and mass flow gain factor, of cavitating inducer were evaluated by CFD using commercial software. Quasi-steady values of cavitation compliance and mass flow gain factor were obtained first by using steady calculations at various flow rate and inlet cavitation number. Then unsteady calculations were made to determine the transfer matrix and the cavitation characteristics. The results are compared with experiments to show the validity of calculations.View full abstractDownload PDF (231K) -
（Investigation of a Flow Direction Control Method by Using a Curved Channel）Shouichiro IIO, Shingo OOIKE, Masahiro YAMAZAKI, Kaika KIMOTO, Yusuke ...Article type: Technical papers
2012 Volume 40 Issue 12 Pages 745-753
Published: 2012
Released on J-STAGE: April 09, 2015
JOURNAL FREE ACCESSPerformance of open type cross-flow runner utilizing waterfall is strongly affected by flow impinging position. It is therefore necessary to keep the stable generation by changing the runner position or controlling the waterfall direction. The former is unrealistic method because of sophisticated mechanism to move the runner. Accordingly, this study focused on the flow direction control method by using curved channel. Flow visualization and runner performance measurement were conducted about two different curvature channels. As a result, it was clarified that the flow direction control method was effective to keep a stable generation when the flow rate changed widely. Namely, the adjustment of runner position is not necessary even when the flow rate changes. This is an extreme advantage from a practical application viewpoint.View full abstractDownload PDF (184K)
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