巻号一覧
33 巻, 4 号
選択された号の論文の7件中1～7を表示しています
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Technical Papers
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新野 崇一, 熊本 圭, 塚本 寛, 宮崎 康次2005 年 33 巻 4 号 p. 199-205
発行日: 2005年
公開日: 2006/10/30
ジャーナル フリーWe conducted computational fluid dynamics(CFD) analysis of centrifugal blood pumps by using commercial code CFX-5 for improvements of a thrombotic and hemolytic performance. We also investigated effects of washout holes of the impeller on thrombus formation around the shaft. Washout holes enhanced flows around the shaft behind the impeller. Numerical simulation suggested that the thrombus formation was suppressed when the position of washout holes was moved to the center of impeller in a radial direction. As for hemolysis, large radial gaps between an impeller and a casing prevented hemolysis although the pump head was slightly decreased.抄録全体を表示PDF形式でダウンロード (1612K) -
正司 秀信, 河合 隆幸2005 年 33 巻 4 号 p. 206-213
発行日: 2005年
公開日: 2006/10/30
ジャーナル フリーTurbulent diffusion rates from the opening between the jet mouth and the suction were obtained from the circulating flow rate Q0, the density of tracer gas C0 and the tracer gas supply Qg which were measured by the closed loop experimental apparatus. Nozzle jet with uniform discharge velocity and pipe jet with non-uniform velocity distribution were examined for the same area suction and the half area suction. In all cases suction gave very small effects to the axial velocity of the jet except very close region of the suction mouth. It was found out the influences of the suction could be well evaluated by introducing the increase diffusion rate. The effects of the gap of the center of the suction pipe were also discussed.抄録全体を表示PDF形式でダウンロード (1775K) -
Part 1: Leakage through Clearance around Runner-BandRuofu XIAO, Caixin WEI, Fengqin HAN, Takashi KUBOTA2005 年 33 巻 4 号 p. 214-222
発行日: 2005年
公開日: 2006/10/30
ジャーナル フリーThe specific energy efficiency ηε of a Francis turbine can be predicted by the 3-D numerical analysis of the main flow through the turbine from the spiral case inlet to the draft tube outlet. In order to predict the discharge efficiency ηQ and the power efficiency ηp of the turbine, it is necessary to perform the 3-D numerical analysis of the leakage flow through the clearances around the runner, under the inflow and outflow conditions for the clearances defined by the main flow analysis. Moreover, a lump-sum analysis of the combined leakage-main flows is prerequisite to investigate the interaction between the leakage flow and the main flow in the turbine. The aim of a series of the papers is to clarify the effect of leakage flows along the runner band and crown on the main flow through the medium-high specific speed Francis turbine. This paper focuses on the numerical analysis of leakage flow through the clearance around the runner band to evaluate the discharge and power efficiencies.抄録全体を表示PDF形式でダウンロード (1861K) -
入門 寛, 御法川 学, 鈴木 昭次, 長松 昭男, 磯本 剛, 伊藤 孝宏2005 年 33 巻 4 号 p. 223-229
発行日: 2005年
公開日: 2006/10/30
ジャーナル フリーThe authors reported in the first report that sound quality of turbomachinery noise has two major factors; "Offensive" and "Booming-Powerful" factors. This second report presents the evaluation of hearing test results using "paired comparison" method in order to investigate the correlation of these two factors with physical quantities that represent noise level and quality such as A-weighted sound pressure level and loudness level. Analysis of hearing tests results revealed that "offensive" factor has positive correlation with the physical quantities such as A-weighted sound pressure, but "booming" factor has negative correlation with them.抄録全体を表示PDF形式でダウンロード (1462K) -
内山 知実, 菊山 功嗣2005 年 33 巻 4 号 p. 230-240
発行日: 2005年
公開日: 2006/10/30
ジャーナル フリーThe propulsive performance of a microblade wiggling in bubbly flow is numerically simulated by a two-dimensional finite element method to search for the efficient propulsion mechanism. The blade, whose geometry is similar to an NACA65-010 hydrofoil, is set in a straight conduit, in which the bubbly mixture flows. The wiggling motion is expressed by a progressive wave with reference to the swimming motions of fish. The bubbly flow is calculated by an incompressible two-fluid model. The calculation reveals the effects of a progressive wave form and volumetric fraction of air upstream of the blade on the propulsive performance. The time variations of the flow properties around the blade are also discussed in relation to the blade motion and propulsive performance.抄録全体を表示PDF形式でダウンロード (2650K) -
横井 嘉文, 稲垣 進2005 年 33 巻 4 号 p. 241-249
発行日: 2005年
公開日: 2006/10/30
ジャーナル フリーIn order to understand the flow feature in the inside of turbo fan, the flow pattern, and the velocity and pressure distributions were investigated by use of the tuft grid visualization method and five holes yaw-meter. The experiments were performed at three typical operating conditions (maximum efficiency discharge case, smaller and lager discharge cases). As a result of experiments, the rotating flow which has an axis to the direction of flow was observed in the spiral casing and it was found that the central position of rotating flow depended on the flow rate. In the case of maximum efficiency, it was found that the static pressure distribution was uniform regardless of the circumference angle among both parallel walls of the spiral casing. It was examined about the fluid outlet angle and the slip factor.抄録全体を表示PDF形式でダウンロード (2274K) -
井上 康弘, 真鍋 明, 風間 剛, 伊藤 寛志, 浜田 紀昭2005 年 33 巻 4 号 p. 250-255
発行日: 2005年
公開日: 2006/10/30
ジャーナル フリーRecently, a bend delivery casing with a rectangular discharge opening is utilized for reducing the cost of a construction. On the other hand, when we investigate the pump performance, it is important to estimate the total head loss in the bend delivery casing. The influences of the guide vane location in the bend delivery casing on the total head loss have been investigated. We predicted the best guide vane location in a bend delivery casing by CFD, and measured the total head loss in experiments, in order to reduce the total head loss in the bend delivery casing According to results of CFD, the total head loss decreased 5.3 percents by optimizing the guide vane setting. On the other hand, the total head loss reduction of 3.5 percents was observed on experiments. The calculated results have met the experimental ones approximately.抄録全体を表示PDF形式でダウンロード (1343K)
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