船舶前缘引流减阻及流场特性数值模拟

为了减少船舶的粘性阻力,针对一条中低速船舶在其前缘开孔引流探索减阻效果。不计自由液面的影响,采用有限体积法和SIMPLEC算法,湍流模型为SSTk-ω两方程模型,压力采用标准格式,动量方程、湍动能方程和湍流耗散比率方程均采用二阶迎风格式,耦合求解Navier-Stokes方程和连续性方程,分析前缘引流对船体周围流场的影响及减阻效果。计算结果与原型船模的对比性分析显示:船艏压力系数明显降低,尾部压力系数有变化,船体壁面切应力略有降低,引流后总减阻率达到2%以上。

Numerical simulation on leading edge holes for drag reduction and flow field characteristics of the craft

In order to reduce the craft’s resistance,the drag reduction effect is figured out by leading edge holes on a medium or low speed craft.Neglecting the influence of free-surface,the Finite Volume method and SIMPLEC algorithm are used,SST k-ω(2 eqns) viscous model is chosen,the standard format for pres-sure,second order upwind format for momentum,turbulence kinetic energy and specific dissipation rate e-quations are adopted.The Navier-Stokes equation and the continuity equation coupled are solved and then the influence of flow field and drag reduction effect by leading edge holes is analysed.The comparison of results shows that the pressure coefficient decreases obviously on the stem and varies on the stern,wall shear stress diminishes slightly and the resistance reduction ratio is greater than 2%.