巻号一覧
30 巻, 6 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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蔦原 道久2002 年 30 巻 6 号 p. 321-329
発行日: 2002/06/10
公開日: 2011/07/11
ジャーナル フリーSimulation method for compressible flows by the lattice Boltzmann model is explained. Especially, the lattice BGK model with multi-speed particles for two-and three-dimensional flows is shown, and the relationship between the particles distribution function and the macroscopic quantities is described. The isotropic feature of the forth order tensor is shown to be necessary for the macroscopic governing equations. The Navier-Stokes equations of a compressible fluid are derivedfrom the lattice BGK equation. As a bench-mark test, the flow in a shock tube is performed, and the result agrees well with an analytical solution or that by the finite difference method. The aeolian tone emitted by a circular cylinder is also simulated, and a dipole emission of sound wave is detected synchronized with the Karman vortex street. The lattice BGK model for compressible fluids is shown to be one of powerful tool for simulation of gas flows.抄録全体を表示PDF形式でダウンロード (6175K) -
今井 誠, 中川 博人2002 年 30 巻 6 号 p. 330-335
発行日: 2002/06/10
公開日: 2011/07/11
ジャーナル フリーPDF形式でダウンロード (3534K) -
井田 富夫2002 年 30 巻 6 号 p. 336-348
発行日: 2002/06/10
公開日: 2011/07/11
ジャーナル フリーThe effect of difference between discharge flow angles from model runners and prototype ones on the actual Euler's head and the efficiency of hydraulic turbo-machines are discussed by using the scale effect formula used at present. Then discharge flow angles from the flat plate cascades similar to the runner vanes of models and prototypes are decided under consideration of boundary layer thickness which changes with Reynolds number and surface roughness. The discharge flow angle difference Δα between models and prototypes and the increase in efficiency en from the efficiency step-up formula are estimated as follows: Francis Turbine (NSQ= 62):Δα= 0.047°, Δη= 0.17% Francis Pump-turbine (NSQ= 33):Δα= 0.079°, Δη= 0.10% The same as above (pump op.):Δα= 0.079°, Δη=0 Kaplan Turbine (NSQ =109):Δα=0.017°, ΔΔ=0.27% where NSQ is the discharge specific speed.抄録全体を表示PDF形式でダウンロード (1478K) -
第1報動翼入口の速度場塩見 憲正, 金子 賢二, 蔡 文新, 西村 正和, 瀬戸口 俊明2002 年 30 巻 6 号 p. 349-356
発行日: 2002/06/10
公開日: 2011/07/11
ジャーナル フリーAn experimental investigation was carried out to clarify unsteady flow fields with rotating stall cell, especially structure and behavior of stall cell, in a high specific-speed diagonal flow fan. As its specific-speed is very high for a diagonal flow fan, its pressure-flow rate curve tends to indicate unstable characteristics caused by rotating stall similar to axial flow fan. Although for an axial flow fan many researchers have investigated such the flow field, for a diagonal flow fan few study has been done. In this study, velocity fields at rotor inlet in a diagonal flow fan were measured by use of a single slant hot-wire probe. These data were processed by use of the “Double Phase-Locked Averaging”(DPLA) technique, i. e. phases of both the rotor blade and the stall cell were taken into account. The structure and behaviors of stall cell at rotor inlet were clarified for three dimensional velocity components, Vm, Vθ, and Vn.抄録全体を表示PDF形式でダウンロード (7927K) -
分散排気口式半横流換気方式における濃度分布の模型実験による検証信田 誠, 福島 邦昭, 村田 栄作, 小松 厚造2002 年 30 巻 6 号 p. 357-362
発行日: 2002/06/10
公開日: 2011/07/11
ジャーナル フリーThis paper represents the verification of Reference [31], in which we have introduced theoretical equations on the above ventilation system, and the diffusion of pollutants. The adequacy of equations were studied through the simulation, using the experiment apparatus of the model tunnel with model vehicles running. Test results indicated that the theoretical values of concentration distribution of contaminated air were very good match with the experimental values. Thus establishing the adequacy of the stated theoretical equation.抄録全体を表示PDF形式でダウンロード (706K) -
伊藤 惇, 富樫 賢一2002 年 30 巻 6 号 p. 363-373
発行日: 2002/06/10
公開日: 2011/07/11
ジャーナル フリーA theory of a three-dimensional cascade with partial cavitation in spanwise shear flow between two parallel plane walls is presented. An equation of motion with respect to disturbance pressure is transformed into two problems by separation of variables. One of them is that of spanwise direction and the other is that of sectional plane of a hydrofoil. For the problem of the spanwise direction, an existing analytical solution is adopted. The problem of sectional plane of the hydrofoil is reduced to a simultaneous integral equation with respect to singularity distributions and is solved by using the analytical method previously proposed by the author for the three-dimensional cascade without cavitation. These two kinds of solutions corresponding to individual eigenvalues are combined linearly, and expressions of cascade and cavity characteristics are obtained. Numerical calculations are carried out to clarify the characteristics.抄録全体を表示PDF形式でダウンロード (1116K) -
その2: 不釣合い振動 (1)塩幡 宏規2002 年 30 巻 6 号 p. 374-379
発行日: 2002/06/10
公開日: 2011/07/11
ジャーナル フリーPDF形式でダウンロード (3052K)
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