基于不同网格类型的某散货船螺旋桨敞水性能预报与研究

Prediction of the open water performance of a bulk carrier propeller based on different grid types

以53 100 t双壳体散货船的螺旋桨为研究对象,分别进行了敞水试验和CFD计算.首先基于Fluent应用RNGκ-ε模型,采用两种网格模型对螺旋桨进行CFD计算,得到其推力系数和转矩系数.并与敞水试验得到的螺旋桨敞水曲线进行对比,发现分区混合网格误差为8.3%,而非结构网格误差为11.4%,分区混合网格误差较小,计算效率更高.结果表明:由于螺旋桨直径大,转速慢,导致雷诺数过低未达到临界值,使Flunet分析的误差较大,通过成比例缩小螺旋桨直径,加快转速,计算结果误差缩小至5.7%,提高了计算精度,达到了预报要求.

A propeller of 53 100 DWT double-hull bulk carrier is chosen to study its open water performance.CFD software Fluent is applied to the numerical simulation. RNG κ- ε model and two kinds of grid model are used to analyze the performance of the propeller and get its thrust coefficient and torque coefficient. Open water test was carried out to get the performance curves of the propeller. The test results are compared with the ones obtained by CFD simulation. The error of partition hybrid mesh is 8. 3%,and the error of unstructured grid is11. 4%. The error of partition hybrid mesh is smaller and the computational efficiency is higher than the one of unstructured grid. The result shows that the error is big because of the large diameter of propeller and the slow speed. The diameter and the speed can make the Reynolds number become too small and make the error too big.When the diameter of propeller is reduced and the rotational speed is increased proportionally the error can be less than 5. 7%,meeting the requirements of the prediction.