浅水航道中门桥水动力特性数值计算

Numerical simulation on hydrodynamic characteristic of pontoon raft in shallow water

本文针对浅水航道中门桥的水动力特性进行数值模拟研究,采用RANS方程结合RNGk-着两方程湍流模型,对一门桥模型在不同水深航道中的阻力、升沉、纵倾和兴波进行数值计算,其中自由面采用VOF方法处理。数值计算时,使用有限体积法离散控制方程,对流项采用二阶迎风格式,扩散项采用中心差分格式。计算结果表明:在Fd<0.6时,水深对门桥的水动力特性影响很小,仅对升沉有一定影响;而随着Fd增大,门桥的阻力、升沉、纵倾及兴波等水动力特性都将发生变化,且水深越浅,表现越明显。

To simulate numerially the hydrodynamic characteristics of pontoon raft in shallow water, the resistance, sinkage, trim and wave of a pontoon raft model in shallow water with different depth were computed by solving Reynolds Averaged Navier-Stokes Equations （RANSE） and Renormalization Group （RNG） k-ε two-equation turbulence model.The free surface was dealt with VOF （Volume of Fluid） method. FVM （Finite Volume Method） was used to discrete the governing equations,the second-order upwind difference scheme was adopted for the convection item and the centric difference scheme for the dissipation item.The calculated results show that when Fd 〈0.6, the depth of shallow water only brings a little influence to the sinkage of pontoon raft; while Fa increases, the influence of depth on the hydrodynamic characteristics such as resistance,sinkage,trim and wave of pontoon raft becomes remarkable,especially in very shallow water.