Study On Flow Structure Of New-Type Sand Basin For Micro-irrigation

New-type sand basin for micro-irrigation is a new-type disposal technology of silt that is put forward to utilize directly surface water resource as irrigation water for micro-irrigation system. The application of new-type sand basin will promote micro-irrigation system to utilize surface water resource to a great extent, so it can enlarge the application rang of micro-irrigation system, and reduce the cost of investment effectively.Based on the indoor model test, theoretical analyses and prototype data, flow structures of the new-type sand basin has been analyzed and studied, and the main research results are as follows:1. The adjusting mechanism of adjusting flow board has been analyzed in theory. Based on the model test and the numerical value simulation, the two both indicate that distribution of flow field is more well-proportioned and distribution of flow field is more advantaged sediment deposition in new-type sand basin than in tradition sand basin; the adjusting flow board can adjust flow in new-type sand basin, weaken the flow's turbulence ,and at last give the rule of adjusting flow board's designing.2. The influence law of spillway crest's sediment concentration, which is influenced by spillway trough, has been analyzed in theory, studied the relation between the length of spillway trough and the water-head of spillway crest, and gave the quantificational formula of two, and the practicability of the formula has also been verified with the prototype data.3. Based on the supersaturated sediment transport of one dimension, the approximate calculation formula of deposition rate with group in each section, groups in working section and greater than some grain degree for sand basin are reduced. The verifying of model test and prototype data indicates that the results of calculation and surveying are accord with each other well, and it can be used in engineering calculation.4. Based on the prototype observation, it indicate that the new-type sand basin can improve deposition rate of silt, the quantity of silt in flow is much less in the end of sand basin, the new-type sand basin can be used in bigger range.