All issues
Volume 35, Issue 6
Displaying 1-6 of 6 articles from this issue
- |<
- <
- 1
- >
- >|
Technical Papers
-
(One Degree of Freedom Weak Coupling Analysis with Hinge-Spring Model)Hiroshi IMAMURA, Yutaka HASEGAWA, Junsuke MURATA, Sho CHIHARA, Kohei K ...2007 Volume 35 Issue 6 Pages 321-329
Published: 2007
Released on J-STAGE: September 24, 2008
JOURNAL FREE ACCESSSince large-scale commercial wind turbine generator systems such as MW-class wind turbine are becoming widely operated, the vibration and distortion of the blade are becoming larger and larger. Therefore the soft structure design instead of the solid-design is one of the important concepts to reduce the structural load and the cost of the wind turbine rotor. The objectives of the study are development of the fluid-structure coupled analysis code and evaluation of the soft rotor-blade design to reduce the unsteady aerodynamic blade load. In this paper, fluid-structure coupled analysis for the HAWT rotor blade is performed by free wake panel method coupled with hinge-spring blade model for the Hap wise blade motion. The calculation results are evaluated by comparison with the database of the ^4REL unsteady aerodynamic experiment. In the analysis the unsteady flapwise bending moment in yawed inflow conditions is compared for different blade frequencies.View full abstractDownload PDF (822K) -
Hideaki TAMAKI, Masaru UNNO, Akira IWAKAMI, Shinnosuke ISHII2007 Volume 35 Issue 6 Pages 330-337
Published: 2007
Released on J-STAGE: September 24, 2008
JOURNAL FREE ACCESSThe flow fields behind a variable area nozzle for a radial turbine were measured with 3-hole yaw probe and calculated with CFD. Two nozzle throat-areas were investigated. One was the smallest opening, and the other was the largest opening for the variable nozzle. The area ratio of the smallest to the largest was 0.27. Test results agreed with the calculated results qualitatively. The flow fields at minimum and maximum opening are presented and discussed. In case of the smallest opening, the leakage flow through the tip-clearance of nozzle vane influenced on the flow field downstream of the nozzle vane significantly. However the effect of leakage flow on the flow field downstream of the nozzle vane was very weak for the case of the largest opening. Extremely different flow fields were observed.View full abstractDownload PDF (2115K) -
Kazuhisa SAIKI, Toshio NISHIZAWA, Osamu NOZAKI2007 Volume 35 Issue 6 Pages 338-345
Published: 2007
Released on J-STAGE: September 24, 2008
JOURNAL FREE ACCESSThe flow simulation of the over-all turbine unit of the fuel turbo-pump for LE-7A engine, which consists of nozzle vanes, rotor blades, stator vanes and an upstream manifold, was conducted. The manifold has struts between a volute and an inner passage. The occurrence of strong unsteady flow in the manifold was clarified by our past research. This paper examines the influence of the manifold flow on the turbine cascade by using CFD. The result shows that both of the circumferential nonuniformity in the manifold and the unsteadiness due to Karman vortices have a strong influence on the turbine loading.View full abstractDownload PDF (2449K) -
Ichiro HARADA, Katsutoshi KOBAYASHI, Sigeyoshi ONO2007 Volume 35 Issue 6 Pages 346-352
Published: 2007
Released on J-STAGE: September 24, 2008
JOURNAL FREE ACCESSIt is important in pump design that the axial thrust of a mixed-flow pump is predicted with accuracy. Predictions of the axial thrust were carried out with CFD for mixed-flow pumps of three specific speeds. The region concerning with the axial thrust prediction was taken out, and was divided into two parts. One of them was the hydraulic part, which included the impeller and the vaned diffuser. The other was the rear part of impeller. Those parts were calculated individually. The CFD results were compared with experimental ones. They showed good agreements. It is shown that the axial thrust for a mixed-flow pump can be predicted using CFD with practical accuracy.View full abstractDownload PDF (1680K) -
Junichi KUROKAWA, Jun MATSUI, Dousith PHOMMACHANH, Noriaki ICHIJO, Tos ...2007 Volume 35 Issue 6 Pages 353-363
Published: 2007
Released on J-STAGE: September 24, 2008
JOURNAL FREE ACCESSIn order to extract micro hydropower in the very low specific speed range, a Positive Displacement Turbine (PDT) was proposed and steady performances was determined experimentally, however the suppression of large pressure fluctuation is inevitable for practical application of PDT.
The objective of the present study is to reveal the mechanism and the characteristics of pressure fluctuation in PDT by use of CFD and to suppress the pressure fluctuation. Unsteady CFD analysis has revealed that large pressure fluctuation is caused by large variation of rotational speed of driven rotor, while the output rotor keeps constant speed. Here is newly proposed a 4-robe helical type runner which can reduce the pressure fluctuation drastically and the performance prediction of new PDT is determined.View full abstractDownload PDF (2897K) -
Yasuo FUKUSHIMA, Minoru HIROSHIMA, Naohiko TAKAHASHI2007 Volume 35 Issue 6 Pages 364-371
Published: 2007
Released on J-STAGE: September 24, 2008
JOURNAL FREE ACCESSA compressor rotor is composed by the several parts, such as impellers, thrust discs, sleeves, and couplings which are shrunk fitted to the shaft.
The contribution to the shaft stiffness by the shrunk fitted elements is discussed, and smaller diameter shaft stiffness penetration to the large diameter section is also evaluated.
Analytical approach by Finite Element Analysis, combined with the experimental investigation of the model compressor rotor results in the accuracy improvement of the natural frequency calculation of the assembled rotor. By the parametric survey, the equivalent shaft stiffness method is proposed for the shrunk elements and shaft stepping. This approach contributes the compressor rotor dynamics design assessment especially supported by the active magnetic bearing.View full abstractDownload PDF (1999K)
Review
- |<
- <
- 1
- >
- >|