Study Of Frozen Ice Jam Backwater Effect Piers Performance

The presence of piers in the river, inevitably leads to a decrease of the local flow area, and water level elevation at a position upstream of the river. But in the freezing period, ice jam changing the hydraulic characteristics of the original river, Comprehensive roughness and resistance frozen was increased in the river, and backwater of the river upstream to generate possibilities is increased. At the moment, consider the research pier is relatively scarce backwater variation exists when ice jams, so this study has important practical significance. This article is based on a calculation of the pier Backwater, Studied the effect of variation of the pier under ice jam upstream backwater by numerical simulation, Provide some technical support and theoretical basis for the construction of winter river ice jam mitigation and bridges. The multiphase flow simulation is mainly used VOF method for free surface tracking, handling software for analysis of the calculation results and using Tecplot and Origin. In addition, we use Fluent dynamic mesh, through the UDF writing implements floating ice jam. The results showed that:Effects of inlet velocity and thickness of the ice jam backwater pier is very significant. The same thickness of ice jam, Backwater height velocity increases with the increase of imports; Inlet velocity is the same, with the increase of backwater ice jam thickness increases; Calculated values than the model specification formula (or empirical formula) is small, Ice jam thickness constant, the smaller, the model calculated values and norms calculated value is closer to the inlet flow rate, as the flow rate increases imports, the deviation between the two gradually increased, but the variation is consistent with the overall presentation. Similarly, the inlet velocity is the same, the thickness of the ice plug is small, the calculated values and the calculated value closer to specification, with the increase of the thickness of the ice-plug, the deviation between the two is gradually increased, but the variation of the overall presentation of the is also consistent.