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金沢大学理工研究域機械工学系, 激しい光路差変動の残る状況下で使える，波長シフト干渉計を用いる粗面の３次元形状計測法を開発している．これまで高温のドライヤー風を吹き付ける状況下での形状計測結果を報告してきた．今回は，通電し温度が上がりつつあるハンダごての形状を風を吹き付けないで測定した．干渉像の位相抽出のための位相シフト量計算を行う空間サイズの効果が確認できた．, 出版者照会後に全文公開

The demand of numerical prediction of wind flow over rough surfaces such as urban areas is increasing. Reproduction of the roughness configuration in the mesh discretization is a direct way for numerical calculations. However, the roughnesses near the ground such as buildings or houses are complicated. Therefore the reproduction increases the computational load and can cost a lot of time and money. In order to reduce this, we applied a filtering operation, that is an averaging in a space containing solid obstacles, to the Navier-Stokes equations and derived filtered equations with a subgrid scale turbulent modeling for the Large Eddy Simulation. Consequently, we can take the obstacles to be porous media distributed uniformly in the mesh. The configuration of the obstacles does not need to be reproduced any further. We can calculate the space-averaged property of flows with coarse meshes and a reduced computational load. We present some calculations of turbulent boundary layer over a rough surface. The performance and effectiveness of the calculation method are examined by comparing with the measured data by wind tunnel experiments.

金沢大学理工研究域機械工学系, 光軸方向に激しい光路差変動の残る状況で使える，波長シフト干渉計を用いる粗面物体の３次元形状計測法を開発している．これまで高温のドライヤー風を吹き付ける状況での形状計測結果を報告してきた．今回は，通電し高温になったハンダごての形状をドライヤーの冷風をあてて測定した．干渉像の位相抽出のための位相シフト量計算を行う空間サイズの効果を，こての温度別に評価した., 出版者照会後に全文公開

A new shape measurement method of rough surface is proposed. The method utilizes a radial shearing interferometry consisting of two zoom lenses with different magnifying powers and a laser diode being able to change its wavelength in a small range less than 0.1 nm. The radial shearing interferometry, known as a kind of common path interferometer, is capable of obtaining a very stable specklegram even under normal vibrational circumstance. From the specklegrams two phase maps corresponding to two slightly different laser wavelengths are extracted. The difference of phase values between two maps is nearly independent of random speckle phase, but depends on optical path differences. Then shape of the rough surface can be calculated from the two phase maps through the optical path differences. The validity of the method is experimentally demonstrated.

application/pdf, 論文(Article), This paper is concerned with a ray searching algorithm based on the imaging method for a three-dimensional (3D) closed space such as a tunnel, underground, office room as well as for a rough surface. First, the fundamental theory of the algoritm is described. Next, it is demonstrat­ed that the algorithm becomes simple when the closed space has a kind of symmetrical property. In this case the extension from two-dimensional (2D) rays to 3D ones is possible. Finally numerical ray examples are shown in 2D and 3D ways for some kinds of structures.

The authors propose a new method which can measure a shape of rough step like surface by means of a speckle interferometry with a wavelength-changeable laser. A speckle phase available in the interferometry is usually affected not only by an optical path difference but also by a random component associated with surface roughness. The phase shifting method using two different wavelengths (λ1, λ2) is, therefore, limited to a single phase map about the optical path difference, because of the random component which remains without cancel. The single phase map is available only for the calculation of the shape of a continuous surface. In the proposed method, the authors use three different wavelengths (λ1, λ2, λ3) to obtain a double phase map, which is capable of a discontinuous surface shape calculation by means of a fringe-counting two-wavelength method. The validity of the method is experimentally demonstrated and discussion is extended to an accuracy of the measurement and an extent of the measurement range.

形態: 図版あり, Physical characteristics: Original contains illustrations, Accepted: 2016-09-08, 資料番号: PA1710000000

金沢大学理工研究域機械工学系, 干渉顕微鏡を用いた垂直走査型３Ｄ形状計測では観察面を一定量高精度に垂直移動させながら干渉画像を取得する必要がある．この方法を振動環境下でも使用したいと考える．そこで顕微鏡観察下の粗面の垂直変位量をラインカメラで高精度に計測する手法を研究した．実験では垂直走査しながら２Ｄカメラを用いて干渉像を連続取込みし，複数線上の光強度を抜き出し，抜き出し位置による変位測定値の違いが最小になる処理方法を追求した., 出版者照会後に全文公開