| Water conservancy projects have an irreplaceable role in the social development and economic construction. However, the water conservancy project will bring us a lot of benefits, but it will inevitably affect the hydraulic characteristics of the original river.In this paper, we simulate the process of water and sand in a hydraulic building. Analysis of different flow rate, inlet arc different gate opening of diversion canal variation of dissolved oxygen and hydraulic characteristics influence for running through the hydraulic structures and combined with channel sediment erosion to increase the dissolved oxygen in the water flow in the channel and effectively improve the channels within the water ecological environment for a certain reference and basis.In this research, we mainly carried out the following work:(four):(1/4, 1/2,3/4, open), the flow characteristics and dissolved oxygen change in four different upstream flow(29L/s, 27.2L/s, 11.4L/s, 17.4L/s). In three different sediment deposition thickness(0, 3.3cm, 5cm), 4 kinds of upstream flow(29L/s, 17.4L/s, 27.2L/s, 11.4L/s) under the sand sand test, in the sand process of three monitoring time points to measure the flow characteristics and dissolved oxygen change.The results were as follows: gate of arc degree of canal water level has little effect, the water level was stepped along the path and decrease the trend, opening the small ladder like distribution trend more obvious; drainage velocity along the path is increased but within the same section velocity distribution is not uniform, velocity on the left bank of the curve was significantly greater than that of the right bank. At the end of the water inlet and the water diversion canal along straight open channel has little effect on the water depth, water depth in the channel was similar to the distribution, is decreasing along the way. With the increase of the radial gate opening, the dissolved oxygen content in the canal is a rising trend, but the change of the dissolved oxygen in the process is different. The different upstream flow, with increase of the upstream flow, water inlet and the water level elevation, upstream to the greater the flow, gate backwater in front of the phenomenon is more obvious; with the increase of flow rate, channel velocity increases and variation amplitude and in the dry season, the water inlet flow velocity in the section with the same difference is big. The variation of water depth in dry season is not uniform; along the water depth decreases first and then increases and then decreases, the maximum value appeared in the curve at the apex. 2-3 rushed in the processes of sediment water inlet of the water level was elevated significantly, with the increase of deposition thickness, high water level of the water inlet area expanded and moved downstream, drainage velocity decreases, expand the area of the inlet velocity is small, but arc gate of small flow area disappear. With the increase of the deposition thickness, the water depth distribution becomes more and more uniform. When the deposition thickness is small, the area of high dissolved oxygen content is small, and when the thickness of the deposit is large, the maximum value of the high dissolved oxygen content is lower. The with the red sand time increased, the overall decline in the water level in the channel, the head of canal water level decreased significantly, the velocity in the diversion canal showed a decreasing trend, velocity distribution becomes uniform, dissolved oxygen in the channel along the history trend: first increased and then decreased, and stage with a peak. |
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