Numerical Simulation On The Thermal Growth Of River Ice Cover

In winter, ice jam often occurs in cold region rivers, it’s a complex naturalphenomenon. Flood caused by the ice jam have great damage on the life and workingof the people along the river. Ice cover is the basis for the formation of ice jam. Theresearch on ice thickness has important significance for study of ice jamformation and evolution. With the rapid development of the computer technology,the numerical simulation is adopted more when it comes to study in ice-watertwo-phase flow. The numerical simulation has become an important methodwhen studying in the ice-water two-phase flow. Based on the heat transmissiontheory and the method of numerical heat transfer, the multiphase model inFLUENT and UDF are used, to establish a2D river model and a3D U-turnmodel, which coupled the thermal and hydraulic conditions. The model treatsthe river as a coupled ice cover-water-ice system taking into consideration theheat exchanges at interfaces in the system, and considers the effect of theaccumulation of frazil ice under the ice cover to the heat exchange through thecover. Under different entrance frazil concentrations, wall-up temperature,entrance flow velocity and depth conditions, simulates and analyses the watertemperature distribution under ice cover, the growth of ice thickness, thedistribution of ice layer under ice cover and the water velocity distribution underice cover. The2D and3D numerical simulation are done. Simulation resultsshow that in the2D case, increasing entrance frazil concentrations, loweringthe wall–up temperature, reducing the entrance velocity, the formation of thethickness of the ice cover will increase; The greater entrance frazil concentration,the distribution of the ice layer under the ice cover is wider and the greater icemaximum concentration is greater; the lower the wall-up temperature, the greaterentrance velocity, the smaller depth, the distribution of the ice layer under the icecover is wider and the smaller ice maximum concentration is smaller. In the3Dcircumstances, the thickness of the ice cover was relatively uniform in theimport of the U-turn model, the ice cover was gradual accumulation in theconvex bank when the stream traversed the import of the U-turn model, andthe thickness of the ice cover in the convex bank was significantly bigger than the thickness in the concave bank. Compared with the data from experiments,the laws in the numerical simulation are similar with them in the experiments.