导管螺旋桨敞水性能的预报和比较

Prediction and comparison of open water performance of ducted propeller

借助于计算流体力学软件,对导管螺旋桨的敞水性能进行了数值模拟,得到了在不同网格模型和湍流模型下导管螺旋桨的正车敞水性能曲线,通过与试验图谱的对比分析,发现Wilcoxk-ω模型更适合于导管螺旋桨的敞水性能计算,并且采用结构化网格和非结构化网格相结合的计算方法能够满足导管螺旋桨敞水性能预报的工程精度要求。同时,当网格中存在少量高度倾斜的网格单元时,在不影响计算收敛的情况下,仍能将计算误差控制在10%以内。此外,如果要获得更为精确的计算结果,应提高网格质量,尽量使用结构化网格,并将近壁面网格加密,合理控制壁面附近的Y+值。虽然网格数量的增加并不总是意味着计算误差的减少,但合理控制网格细密度能够获得更为可信的计算结果。

The open water performance of a ducted propeller was simulated by using computational fluid dynamics software. The validation of different mesh models and turbulence models were discussed. By comparison of calculated results with experimental data, it was found that Wilcox turbulence model is the best turbulence model in simulating the open water performance of a ducted propeller. The study also indicates that the present computational approach with combined structured meshes and unstructured meshes is both practicable and accurate enough for more realistic problems. When the mesh model has a few of highly skewed elements, the calculated errors can also be controlled within 10 percent if the convergence of simulation is obtained. Moreover, for more detailed and accurate results, the improvement of mesh quality is recommended. The mesh refinement does not always mean the reduction of error, although it can bring reliable results.