http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Cavitation Surge Suppression of Pump Inducer with Axi-asymmetrical Inlet Plate
Kim, Jun-Ho,Ishzaka, Koichi,Watanabe, Satoshi,Furukawa, Akinori Korean Society for Fluid machinery 2010 International journal of fluid machinery and syste Vol.3 No.1
The attachment of inducer in front of main impeller is a powerful method to improve cavitation performance. Cavitation surge oscillation, however, often occurs at partial flow rate and extremely low suction pressure. As the cavitation surge oscillation with low frequency of about 10 Hz occurs in a close relation between the inlet backflow cavitation and the growth of blade cavity into the throat section of blade passage, one method of installing an axi-asymmetrical plate upstream of inducer has been proposed to suppress the oscillation. The inlet flow distortion due to the axi-asymmetrical plate makes different elongations of cavities on all blades, which prevent the flow from becoming simultaneously unstable at all throat sections. In the present study, changes of the suppression effects with the axial distance between the inducer inlet and the plate and the changes with the blockage ratios of plate area to the cross-sectional area of inducer inlet are investigated for helical inducers with tip blade angles of $8^{\circ}$ and $14^{\circ}$. Then a conceivable application will be proposed to suppress the cavitation surge oscillation by installing axi-asymmetrical inlet plate.
Tsuruta, Daisuke,Hayashi, Akihide,Kobayashi, Hiromi,Nakagawa, Koichi,Furukawa, Masayoshi,Ishii, Masamitsu S. Karger AG 2005 Dermatology Vol.210 No.4
<P>We describe 4 cases of pseudocyst of the scalp, which still is only being described in the Japanese literature. The tumor is characterized as follows: localized between the top and the forehead area of the scalp, it first appears as a solitary reddish, painful small nodule or papule; it then gradually increases in size, protruding into a dome-shaped mass, and becomes associated with alopecia limited to the lesion area. This report describes typical cases of pseudocyst of the scalp, reviews the reported Japanese cases and introduces this tumor to western dermatology.</P><P>Copyright © 2005 S. Karger AG, Basel</P>
Cavitation in Pump Inducer with Axi-asymmetrical Inlet Plate Observed by Multi-cameras
Kim, Jun-Ho,Atono, Takashi,Ishizaka, Koichi,Watanabe, Satoshi,Furukawa, Akinori Korean Society for Fluid machinery 2010 International journal of fluid machinery and syste Vol.3 No.2
The attachment of inducer in front of main impeller is a powerful method to improve cavitation performance; however, cavitation surge oscillation with low frequency occurs with blade cavity growing to each throat section of blade passage simultaneously. Then, one conceptual method of installing suction axi-asymmetrical plate has been proposed so as to keep every throat passage away from being unstable at once, and the effect on suppression of the oscillation were investigated. In the present study, cavitation behaviors in the inducer is observed with distributing multi-cameras circumferentially, recording simultaneously and reconstructing multi-photos on one plane field as moving a linear cascade. Observed results are utilized for discussion with other measuring results as casing wall pressure distribution. Then the suppression mechanism of oscillation by installing axi-asymmetrical inlet plate will be clarified in more details.
Internal Flow of a Two-Bladed Helical Inducer at an Extremely Low Flow Rate
Watanabe, Satoshi,Inoue, Naoki,Ishizaka, Koichi,Furukawa, Akinori,Kim, Jun-Ho Korean Society for Fluid machinery 2010 International journal of fluid machinery and syste Vol.3 No.2
The attachment of inducer upstream of main impeller is an effective method to improve the suction performance of turbopump. However, various types of cavitation instabilities are known to occur even at the designed flow rate as well as in the partial flow rate region. The cavitation surge occurring at partial flow rates is known to be strongly associated with the inlet back flow. In the present study, in order to understand the detailed structure of internal flow of inducer, we firstly carried out the experimental and numerical studies of non-cavitating flow, focusing on the flow field near the inlet throat section and inside the blade passage of a two bladed inducer at a partial flow rate. The steady flow simulation with cavitation model was also made to investigate the difference of flow field between in the cavitating and no-cavitating conditions.