Study to develop a network system of snow removal channels

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In order to develop the design of the snow removal channel network, it is necessary to understand the hydraulic characteristics of open thermal flow with complex geometries such as the refraction, the branch and the joint which are the basic features of the snow removal channel network. The hydraulic experiment the snow removal channels were carried using the model open channel which has the refraction, branch and joint parts in the laboratory. The flow mechanism and the transport mechanism of snow are investigated in the experiments. The flow velocity distributions were measured preciselyin the each section near the refraction, branch and joint parts. The shapes of the water surface, which is the basic feature of the open channel, were also measured prescisely in the cases of the refraction, branch and joints of channels.To clarify the transport mechanism of snow chunks in a snow removal channel, the experiments of throwing actual snow or model snow using plastic balls were carried ou … More t. In the experiment, the value of water discharge were changed for the several cases and the interval of throwing snow chunks were also changed. The mechanism of blocked or flowing down of snow chunkes are investigated prrecisely. In the refraction channel and joint channel, the snow chunkes were sometimes blocked in some case of the time interval of throw. Almost all snow chunks were blocked in the branch channel. These results should be taken into account when we will design the network of the snow removal channels.To grasp the flow feature of water in the channel, the analytical model calculating the open-chennel with the side inflow or outflow are presented. This model were based on the conservation equation of kinetic energy of mean flow insrtead of the conservation equation of momemtum. This model can consider the energy loss of complex geometries ; I.e. the variation of the channel width and the branch and joint of the channel.The presnt analytical model of open channel flow explains well the experimental results of the surface shape of the refraction and the joint of channel with no snow chunkes, because the model can take the energy loss of such geometry into account. The measurement of surface shape with snow chunkes are very difficult, because the flow with large chunkes are essencially unsteady and the water surface are is varied in time and space. The model also explains roughly the surface shape with snow chunks. Less