Numerical Simulation Study On The Hydraulic Characteristics Of Flood Diversion Sluice Gate

With the development of computer application technology, the simulation model is established by means of computer and professional software, and the numerical simulation method is developed. Using numerical simulation will greatly reduce the workload of the physical model test, and can easily carry out the program comparison, especially for the need to focus on the part of the analysis. Flood diversion sluice operation condition is complex and changeable, the inlet flow is very complex, improper not only affects the flood diversion capacity, may also produce the refluxing swirl to harm the security and stability of the building. The software FLUENT, the RNG turbulence model and VOF method is selected to carry out the numerical simulation to study the effect of flood diversion angle, the split ratio of flood diversion effect, and to study the flood angle of 90 degrees for the flood diversion gate type. The following conclusions:1. The split ratio decreases with the increase of the inlet angle, and the ratio of the small inlet to the flood angle is smaller, and the split ratio decreases obviously when the flood angle is large.2. Flood diversion gate before the river there are seven hydraulic characteristics of regional: velocity stability zone, accelerating zone, spiral flow area, deceleration diffusion zone, the stagnation of spiral zone, stagnation zone.3. The bigger the split ratio, the more uniform the velocity distribution, the smaller the recirculation zone. But the split ratio is bigger, the river sediment more easily into the channel, blocking the floodway and influence of flood. The greater the inlet angle is, the faster the transverse circulation is formed in the channel, and the intensity is stronger.4.With the increase of the inlet angle, the main flow to the left and the right low velocity zone is enlarged, the transverse circulation is weakened, and the phenomenon of water stratification is gradually disappearing.The velocity distribution of the river channel changes little with the change of the inlet angle, and basically accord with the flow characteristics of open channel water.5.Water diversion mouth should be selected for bell type. The larger the size of the entrance, the rectification effect is better, more uniform flow into the gate. But during the closing of the gate, a wider mouth means a stronger return strength and a greater length of the recirculation zone, which is not conducive to prevent silt.Finally, selects the Reynolds stress model to simulate the process of flood diversion sluice Dong Da wei. Compared with the simulation results of the physical model, the difference between the open flow rate, the velocity distribution of the gate, flow regime in the lower reaches of the sluice gate. It shows that the numerical model and the numerical calculation method are reasonable.