On the Laws of Resistance to Turbulent Flow in Open Smooth Channels

It is generally considered that differing from the pipe flow, the flow in open channels has a free surface and waves appearing on water surface relate to some extent with .the laws of resistance on turbulent flow in open channels. According to the above opinion, instability of flow is connected with the mixing length of turbulence; and computing the velocity distribution by Prandtl's equation which expresses the flow near the wall, Froude Number is introduced with Reynolds Number in the laws of reistance on turbulent flow in open channels. Applying this theory, experimental results by authors, Dr. Matuo and R. W. Powell with smooth open channels can be explained within the region of sub- and supercritical flow, and, therefore, the difference between the laws of resistance to turbulent flow in pipes and that in open channels can be made clear

On the Rollwave-Trains Appearing in the Water Flow on a Steep Slope Surface

When we carefully observe a thin sheet flow with a suitable depth on a surface or in a channel of which the slope is greater than about 2%, we can see small continuous wave-trains moving to the down-stream with a uniform wavelength. For instance, we often find them on a road surface with a steep slope in a heavy rain, and the wave-trains in a thin sheet flow of rain-wat.er are called “rain wave-trains”. These wave-trains are rollwaves with a wave-height of several times the mean water depth and it is said that they have a close connection with the soil erosion, but researches on such wave-trains are few and unsatisfactory. In this paper, in order to obtain a foothold necessary to study the relations between the soil erosion and these rollwave-trains from the point of view .of civil and agricultural engineering, the hydraulic properties of the wave-trains are researched theoretically and experimentally by the wooden flume with a smooth bed. At first. a criterion in which the rollwave-trains begin to appear is determined, and then the various properties of the wave-trains, i.e. period, wave-length and .wave-velocity etc. are ascertained by using an electromagnetic oscillograph or a cathoderay oscilloscope and recording the wave-profile

Tatami and wood: ink rubbings and the discussion of materiality in postwar Japanese calligraphy and art

This paper discusses the relationship between postwar Japanese avant-garde calligraphy and the abstract art of the 1950s, showing how calligraphy contributed to the international postwar discussion of materiality. Postwar Japanese art – as exemplified by the art collectives Gutai and Mono-ha – is widely recognized for its close attention to materiality. This study will introduce Japanese avant-garde calligraphy into the discussion of materiality, examining the relationship between the avant-garde calligraphers’ use of traditional takuhon ink rubbings and the technically identical surrealist technique of frottage, invented in 1924 by Max Ernst as a way to implement ideas of automatism in art and to release the ‘material’ from conscious control. The first attempt to examine the encounter between Japanese calligraphy and surrealism, this study argues that when Japanese avant-garde calligraphers such as Inoue Yūichi (1916–85) and abstract painters such as Hasegawa Saburō (1906–57) began incorporating traditional takuhon ink rubbings into their active art practice in the 1950s, they introduced a new dimension of spirituality into the international discourse on materiality