Measurement of Added Resistance in Irregular Waves and Estimation of the Long-period Components
Measurement of Added Resistance in Irregular Waves and Estimation of the Long-period Components
复制标题
不规则波中附加电阻的测量和长周期分量的估计
DOI：
10.2534/jjasnaoe.24.181
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
J. Fujisawa
中科院分区：
文献类型：
--
作者：
M. Kuroda;K. Takagi;M. Tsujimoto;J. Fujisawa
波浪附加阻力是船舶在实际海况中性能评估的重要内容之一，准确计算波浪附加阻力具有重要意义。海洋波浪是由不同频率和方向分布的波浪组成的短峰不规则波。短峰不规则波中的附加阻力通常由规则波中的方向波谱和附加阻力的频率响应叠加而得。迄今为止，规则波附加阻力的各种评价方法已被水池试验所证实。另一方面，不规则波中附加阻力的估算方法很少被水池试验验证，因为给定的恢复力对不规则波中的长周期变化有影响。本文进行了VLCC和PCC模型在长峰不规则波中的水池试验，测量了不规则波中的附加阻力，并与纽曼近似法的估算结果进行了比较。结果表明，长峰不规则波附加阻力的实测长周期变化可用纽曼近似表示，考虑波高效应的纽曼近似估算长峰不规则波平均附加阻力的结果比不考虑波高效应的结果更能解释试验结果。
Added resistance due to waves is one of the major components for the evaluation of ship performance in actual seas, and it is important to be calculated accurately. Ocean waves are characterized as short crested irregular waves which consist of waves with various frequency and directional distribution. Added resistance in short crested irregular waves is usually evaluated by the superposition of directional wave spectrum and frequency response of added resistance in regular waves. Various evaluation method for added resistance in regular waves has been confirmed by tank tests so far. On the other hand, estimation method for added resistance in irregular waves has rarely been verified by tank tests since a given restoring force to a ship model affects to the long-period variation in irregular waves. In this paper, tank tests in long crested irregular waves for VLCC model and PCC model have been conducted, and added resistance in irregular waves has been measured and compared with the estimated results by the Newman's approximation. As a result, it has been shown that the measured long-period variation of added resistance in long-crested irregular waves can be expressed by the Newman's approximation and that the estimated results of averaged added resistance in long-crested irregular waves by the Newman's approximation with the consideration of wave height effect explained the experimental results better than that without the consideration of wave height effect.