引气槽减阻特性的数值研究

Numerical research on drag reduction characteristics of air ducts

为了考察三体滑行艇的引气槽在高航速下的减阻效果,采用数值手段模拟了不同三体滑行艇模型在容积弗劳德数从3.14到5.83的静水直航运动。通过计算值与试验值的对比,验证了数值方法的有效性。计算结果表明,相比于无引气槽模型,引气槽内凹所形成的拱度增大了断级后空穴的范围,减少了航行中的摩擦阻力;引气槽在Fr≥4.93的航速下有着较好的减阻效果,最大减阻收益为5.9%。降低引气槽拱度后,空穴范围变小,阻力性能变差;而增大引气槽拱度在容积弗劳德数从4.04到4.93时阻力有所降低,但空穴范围仍较原模型要小。

To investigate the drag reduction effectiveness of air ducts on planning trimaran hull,a numerical simulation method is used to simulate still water straight navigation movement of three-body sliding skimming boat models under the volume based Froude number from 3.14 to 5.83. By comparison between the calculated value and experimental value,the effectiveness of the numerical method is verified. The calculation results show that,compared with the model without air duct,the camber formed by the inner concave of air duct has increased the range of air cavity behind step,and reduced the sailing frictional resistance. The air duct has a good drag reduction effectiveness under the sailing speed of which Froude number is above or equals 4. 93,and the maximum drag reduction benefit is 5.9%. When the camber of the air duct is decreased,the range of air cavity diminishes and resistance performance becomes worse. While,as the camber of air duct is increased,the total resistance decreases at Froude numbers ranging from 4.04 to 4.93,but the air cavity is still smaller than the original model.