浅吃水肥大型船的尾部线型研究

从分析船舶尾部伴流场对船舶阻力推进,操纵及船体振动性能等影响的观点,研究尾部三维伴流场,介绍尾型与伴流场之间关系及非对称双尾鳍船型的形成。非对称双尾鳍船型与优选的常规双尾鳍船型模型的阻力,自航及伴流场等比较试验结果表明,非对称双尾鳍船具有两大优点,首先,该船型能在浆前方产生一个与外旋浆旋向相反的预旋流,在保持了优良阻力性能前提下可提高外旋浆推进效率8％,获得阻力,推进,操纵各性能间的最佳配合,第二,轴向伴流分布比较均匀,满足BSRA5项衡准指标,改善了螺旋浆工作的流场条件,减少了螺旋浆产生空泡及其诱导船体激振的危险,使节能与减振得到统一,最后还介绍了该船型首制船“宁安1号”的实船测试结果及其由船模试验预报实船性能的一致性。

Study on Stern Forms of Full Shallow Draft Ships

From the view point of the influence of wake field behind ship stern on resistance,powering performance, manoeverability,hull vibration etc.,three dimensional wake fields have been investigated. The relationship between stern forms and wake fields and the configuration of asymmetrical twin-skeg ship form are described in the paper.The comparison of the test results of resistance,self-propulsion and wake fields between asymmetrical twin-skeg ship form and optimized convensional twin-skeg ship form has indicated that the asymmetrical one has two merits.One is that the ship form can produce preswirl flow before propeller disc against the rotational direction of outward rotating propeller.In precondition of keeping constant resistance,the propulsion efficiency can be increased by 8%.It makes a good matching of ship resistance, propulsion and manoevering characteristics.The other merit is that the axial wake distribution is more uniform, which will satisfy the five items of BSRA Criteria, improve propeller working condition and reduce propeller cavitation as well as induced ship hull vibration.Fianlly,the trial results of the ship "Ning An No. 1"that is the first ship adopting this ship form is given in the paper, which agrees with the prediction from the model test data.