流れの可視化画像における速度勾配テンソルの自動計測-水素気泡法により可視化された渦領域の流れ- [in Japanese] Automatic Measurement for the Velocity Gradient Tensor in the Images of Flows -Flows in the Vortex Region Visualized by Hydrogen Bubble Techniques- [in Japanese]
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The vortex flows in the wake of a circular cylinder were visualized by hydrogen bubble techniques. The images of the flow past a bubble generating-wire frozen by a flashing light were consecutively exposed on a moving roll-film in a camera to save the waiting time for the next exposure. A method of image processing for the automatic measurement of the temporal velocity profiles crossing the generating-wire was developed in the digital-images of the flow captured in a micro computer. The successive data of the temporal velocity profiles were transformed into the data in space domain by use of Taylor-hypothesis, and the procedure to determine space derivative of the velocity, i.e., the velocity gradient tensor was established to investigate the kinematic structure of the vortices in the wake.
- Transactions of Visualization Society of Japan
Transactions of Visualization Society of Japan 18, 5-6, 1998-09-01
The Visualization Society of Japan