高航速下KCS模型艏波破碎与艏部涡量数值研究

Numerical study of bow wave breaking and vorticity of KCS under high speeds

基于RANS方法,研究了高航速下KCS模型在静水工况中的艏波破碎。采用自主开发的水动力求解器naoe-FOAM-SJTU,数值模拟了5个航速下(Fr=0.26,0.35,0.375,0.40,0.425)KCS的兴波流场。将Fr=0.26时工况的流场模拟结果与以往实验结果进行了对比,验证了数值方法和网格设置的可行性。为了研究艏部破波的结构和机理机制,分析对比了中高速工况(Fr=0.35)和高速工况(Fr=0.40)下的艏部兴波结构、涡量场以及速度场等。结果表明当前数值方法可以精确捕捉艏波的翻卷以及对应的凹陷。此外,对Fr=0.35工况下船艏处的横向切面和纵向切面云图进行了详细探讨,分析了艏波破碎过程中涡量场、速度场的变化。

In this paper, RANS model is used to study bow wave breaking of KCS model under high speeds in calm water.Numerical simulations under five speeds(Fr = 0.26,0.35,0.375,0.40,0.425) are carried out in our in-house CFD solver naoe-FOAM-SJTU. The comparison between CFD and model test data at Fr = 0.26 indicates the feasibility of present numerical methods and grid distribution. In order to study the structure and mechanism of bow wave breaking, the comparisons of bow wave structure, vorticity and velocity at medium-high speed(Fr = 0.35) and high speed(Fr = 0.40) are analyzed. The results indicate that present numerical methods can accurately capture the bow wave overturn and induced scar. In addition, detail analysis of vorticity field and velocity field under different transverse and longitudinal cuts at Fr = 0.35 is presented.