抄録
Investigation on the characteristics of unsteady pipe and duct flows is increasingly important because of precise control of these flows and safety of pipelines in many industrial processes. A variety of methods have been developed for producing various types of unsteady flows. Unfortunately, those capable of producing unsteady flows of arbitrary history are very limited. In this study a butterfly valve is used and it is driven by a stepping motor following programmed rotation speed. The valve is not rotated but swung around its supporting rod. Constant-acceleration flows, constant-deceleration flows, and pulsating flows with sinusoidal and triangular waveforms can be generated with sufficient accuracy.
