七叶侧斜螺旋桨水动力性能优化

Hydrodynamic Optimization of a Seven-Bladed Propeller with Skew

论文对某七叶侧斜螺旋桨进行了多目标数值优化。螺旋桨的弦长分布由多项式来表达,螺距、拱度和侧斜分布由B样条曲线控制。剖面厚度分布由PARSEC表达式修改,并采用SJ系列拱线代替了原始拱线。螺旋桨的性能预报采用面元法,优化算法采用非排序微分进化算法。首先由相关度分析减少设计变量并确定其取值范围,然后以效率和叶梢最小压力为目标进行优化,并采用开源程序Open Foam对优化结果进行了RANS计算和分析。计算结果表明:优化桨的盘面比更小但叶梢侧斜略大,折中优化桨效率比原桨提高约2%,且叶梢压力分布有所改善。

Multi-objective optimization for a seven-bladed propeller with skew is carried out in this paper. Parameterization of the propeller blade is performed with a polynomial for the chord distribution and the B splines for the pitch, camber and skew distributions. The original thickness distributions and mean lines of blade sections are modified by PARSEC expression and replaced by SJ series mean line respectively. A boundary element method based on the potential flow is utilized for prediction of performance. Non-dominated sorting differential evolution （NSEA） algorithm is chosen for the optimization. Correlation analysis between design variables and objectives is executed for the sake of reducing design variables and determining their value ranges. In the optimization, the objects are the open water efficiency and the minimum pressure peak near the blade tip. Optimized propellers are evaluated and analyzed by RANS method using the open source code OpenFoam. The results show that the optimized propeller has a lower ratio of expanding area and higher skew at the blade tip. The efficiency of optimized propeller is 2% higher than the original one and has better pressure distribution at the tip region.