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論文(リポジトリ)

論文(リポジトリ)
小林, 睦夫 ; 前川, 博 ; 高野, 剛 ; 内山, 則之 ; 窪田, 正博 ; 小林, 良充
出版情報: 日本機械学会論文集. B編 — 日本機械学会論文集. B編.  54  pp.3354-3361,  1988-12.  日本機械学会
本文リンク: http://hdl.handle.net/10191/5725
概要: Mean flow properties and one-point multiple velocity correlations including turbulent stresses have been measured in a two-dimensional turbulent flow through a curved channel with a radius ratio of 0.92. The results for the fully developed region are presented and compared with those of a parallel plate channel. The turbulence energy balance shows that the greatly enhanced turbulent diffusion away from the outer wall extends to about 2/3 of the cannel width, and reduces the equilibrium layer thickness considerably. It is found that an existing model for the pressure-strain correlation simulates with good accuracy the experimental values obtained from the turbulent stress balance. The triple correlation balance reveals that the terms relating to the mean flow are of the same order of magnitude as other terms even in the core region where turbulent diffusion plays an important role. 続きを見る
2.

論文(リポジトリ)

論文(リポジトリ)
前川, 博 ; 小林, 睦夫 ; 矢代, 一男
出版情報: 日本機械学会論文集. B編 — 日本機械学会論文集. B編.  53  pp.2560-2566,  1987-08.  日本機械学会
本文リンク: http://hdl.handle.net/10191/5720
概要: A temperature-sensitive hot-wire under constant-temperature operation is analyzed to predict its frequency response to temperature fluctuations of the fluid. Effects of the finite Wollaston length, the over-heat ratio and the transconductance of the amplifier are taken into account, and a precise expression for the transfer function is derived. Various probes with different geometries are dynamically calibrated using the new developed procedure, in which a linear temperature distribution or a thermal wake just behind parallel line-sources is utilized to generate prescribed temperature fluctuations over a wider range of frequencies. Good agreement is obtained between the predictions and the experimental results on the gain of the sensitivity. The gain increases slightly as the over-heat ratio increases, and is least affected by the transconductance. Owing to the moderate thermal inertia of the Wollaston portion, the attenuation in the gain sometimes appears in the range of energy-containing eddies. 続きを見る
3.

論文(リポジトリ)

論文(リポジトリ)
小林, 睦夫 ; 前川, 博 ; 高野, 剛 ; 平塚, 真二
出版情報: 日本機械学会論文集. B編 — 日本機械学会論文集. B編.  52  pp.298-304,  1986-01.  日本機械学会
本文リンク: http://hdl.handle.net/10191/5717
概要: When a cylinder is placed perpendicular to a uniform flow of fluid, the upstream velocity vector can be determined from the velocities measured at two points in the region where the streamlines are deformed by the cylinder. Based upon this principle, a new type of probe, which possesses similar directional sensitivity to an X-probe and is suitable for anemometry in a narrow space, has been devised. Since the hot-wires are put outside the boundary layer on the cylinder, the optimal location for each wire can be examined by analysing the sensitivities for the probe operating in a plane inviscid flow. The probe, with a cylinder of about 0.1 mm in diameter, is calibrated statically and dynamically, and applied to measuring turbulent stresses and power spectra in simple flows. The experiment shows that this type of probe is reliable in various measurements of gaseous turbulence. 続きを見る