Study On Film Hole Border Irrigation Water Flow Advance Test And Numerical Simulation

Based on the theory and advanced technology of film hole irrigation in previous research. This thesis focus on the relationship between the promoting distance and the movement time of water flow in film hole irrigation, using the methods of field experiments, numerical simulation and theoretical analysis. According to the characteristics of soil infiltration in actual field experimental areas and the basic geometric parameters, also assumed that different manning roughness to simulate the process of water flow promoting, the field manning roughness is obtained when the simulating results have a good agreements with the field tests. Using field manning roughness we can simulate other elements of water flow promoting, and further research water composition of film hole irrigation by water balance model, it lay a strong foundation for the application and development of film hole irrigation in field. The main research results and conclusions are as follows:(1) Through the tests of film hole irrigation in field, verify the power relationship between the promoting distance and the movement time of water flow Based on the relationship we can choose the optimal groups under different film hole diameters and water flow rate.(2)Obtained the characteristics of soil infiltration through randomly select the places in the field. According to the characteristics of soil infiltration and the basic geometric parameters, assumed different manning roughness use the SRFR software to simulate the water flow promoting in film hole irrigation. The field manning roughness is obtained when the simulating results have good agreements with the actual tests.(3)Through the field manning roughness, we can simulate other elements ,such as water flow recession time and the variation of water flow in different places and water depth in the beginning border. Using these results we can do more research about the water movement in film irrigation.(4)In border irrigation, the water depth in the beginning border is used to calculate field manning roughness, By analyzing water depth in the beginning border in film hole irrigation, the value of field manning roughness is also can be calculated.(5)By using water movement model and field manning roughness analysised the water composition in film hole irrigation it demonstrated that the total water include surface water storage, infiltration water through film hole and the loss of water. The loss water contains film water storage and two dimensional infiltration water along the film hole wetting pattern, it makes irrigation water use efficiency and the utilization of water resources more higher than the tradition method.