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The flow-field and the acoustic-field around moving bodies are simulated by the Arbitrary Lagrangian Eulerian formulation in the finite difference lattice Boltzmann method. The validity of the ALE is checked by comparing flow about a square cylinder in ALE formulation and that in the fixed coordinates, and both agree very well. Matching procedure between the moving grid and fixed grid is also considered. The proposed method in which the both grids are connected through buffer region is shown to be superior to moving overlapped grid. Dipole-like emissions of sound wave from harmonically vibrating bodies in two- and three-dimensional cases are simulated. Sound wave emitted from rapidly rotating elliptic cylinder is also successfully simulated.

The hydrodynamic forces generated by interaction between water and a rectangular cylinder have been investigated experimentally. Five rectangular cylinder models of 6, 12, 30, 60 and 120 mm width, 60 mm height and 200 mm span were used. A period parameter ranged from 0.2 to 3.2 in the investigation. The test frequency was 2 Hz. The characteristics of the hydrodynamic force acting on a circular cylinder, square cylinder, diagonal square cylinder and elliptic cylinder reported previously by the present authors depended on the period parameter but not on the Reynolds number and the test frequency less than 6 Hz. The results are as follows : the hydrodynamic force coefficient, the wave form and the phase difference to the period parameter are shown : the effects of the cross sectional width/height ratio to the force coefficient and the phase difference are explained.

A correction formula is proposed for wall effects on unsteady separated flow around bluff bodies, which is derived from numerical results by the discrete vortex method on two-dimensional separated flows around an inclined flat plate, a square cylinder and an elliptic cylinder. The present formula is found to estimate reasonably well the wall effects on the mean and fluctuating flow characteristics in a wide range of the blockage ratio and the angle attack.

The characteristics of the fluid dynamics of the two-dimensional square cylinder were investigated experimentally in case that the parameters were the blockage ratio and the gapratio s/h, where s means the gap between cylinder and plane wall, h the side length of the cylinder. The time-mean fluid force and fluctuating force the cylinder rapidly increased when the gap ratio was over the critical value (s/h)cr. This critical value (s/h)crcr decreased with the increase of the blockage ratio. It was also found in the visualization experiment that the Flow patterns around the cylinder were classified into two patterns on the boundary of this critical value.

The forces generated by water-square cylinder interaction have been investigated experimentally. Three kinds of square cylinder models of 50 mm, 75 mm and 100 mm width were used. The square cylinder with two endplates was oscillated horizontally in standing water by mechanical oscillation machinery. The force was measured by means of a quartz force transducer. Period parameters ranging from 0.2 to 1.8 and Reynolds numbers from 450 to 51460 were covered in the investigation. The results have shown that the wave forms of the forces depend on period parameters and Reynolds numbers, and the force amplitude coefficients are determined only by period parameters.

The characteristics of the fluid forces acting on a square cylinder and flow patterns around the cylinder experimentally investigated when the cylinder was placed near and in a free turbulent mixing layer. The flow patterns near the under side of the cylinder, which faces to the high velocity side of the mixing layer, were found to be divided into the perfect separated flow (η - 0.05) . At this boundary ηMc, the time-mean lift force attained its minimum value. It became also clear that the fluctuating fluid forces were very small over ηM and their distributions with respect to η had similarities when h / δl 0.617, h being the side length of the cylinder and δ the width of mixing layer.

プレートフィンチューブ形熱交換器の基本的な構造モデルを、プレートフィンとしての平行平板の間にチューブとしての正方形柱を垂直に設置した流路と考え、その流動および熱伝達を解明する。本報では、レイノルズ数Re=200の場合の流動の解析を行い、速度ベクトル、流跡線、等圧線、壁面におけるせん断応力の分布およびはく離線を明示し、また流れの非定常性について考察を加え、流路内の流動機構について詳細な検討を行う。

Finite-difference analyses of the two-dimensional Navier-Stokes equations were given in stream function-vorticity formulations from the range of the steady state to the range of the unsteady vortex street behind a square cylinder placed in the middle of a flow channel between two parallel walls. For flows in a multiply-connected region, the value of the stream function on the body cannot always be given a priori. A new method to determine this value was proposed for getting the circulation flowing out of a control surface set behind the body. Transitional phenomenon from a steady state of the twin-vortices to an unsteady state of the vortex street was successfully reproduced with good agreement with experimental results.

The hydrodynamic forces generated by water-square cylinder interaction have been investigated experimentally. A square cylinder model of 50mm side length and 200mm span length, and five kinds of end-plates of 100, 200, 300, 400, 500mm width were used. The cylinder supported by two end-plates was oscillated horizontally in standing water by mechanical oscillation machinery. The force was measured by means of a quartz force transducer. Period parameters ranging from 0.2 to 3.0 and Reynolds numbers from 5000 to 40000 were covered in the investigation. The results have shown that the force amplitude coefficients based on the acceleration of two-dimensional square cylinder are obtained at end-plate dimensions of greater than 10 times the square cylinder side length, and the force amplitude coefficients and the force wave forms depend on the period parameter but not on the Reynolds number.