钻井船月池流场与阻力数值预报方法和回归分析研究

发布时间：2018-09-13 17:00

【摘要】：由于作业需要,钻井船会在接近船舯位置设置开口较大的月池开口,给航行阻力性能带来不利的影响,而国内对月池引起阻力增加的研究还处于起步阶段。基于此,本论文结合国家发改委“3000米深水钻井船设计建造关键技术研发及产业化”课题,采用数值计算和模型试验相结合的方法对钻井船阻力性能开展了研究工作。首先,对计及月池的钻井船粘性流场定常和非定常CFD模拟方法进行了研究。对带有4个不同月池的同一钻井船进行了定常CFD模拟,并与试验结果比较,结果表明定常CFD方法预报的阻力在水体振荡并不剧烈的低航速时有效,高航速时偏小;对带直壁型月池和阶梯型月池的同一钻井船进行了非定常CFD模拟,结果表明非定常方法能够考虑月池内水体非定常运动对阻力的影响,因而结果更准确。基于CFD模拟结果,对月池附加阻力成因进行了分析。其次,对钻井船月池附加阻力进行了试验研究。模型试验在上海交通大学循环水槽实验室完成,研究了不同月池形式、尺度和吃水对月池附加阻力的影响规律。结果表明,同一月池在不同航速下会表现处不同的振荡模式,但在吃水-月池开口长度比小于0.4时更容易体现为“晃荡”模式;两种振荡模式下,月池附加阻力与月池内水体振荡幅度各自呈线性关系;月池内流体会在一定航速范围内维持同一频率的振荡模式,即存在“锁频”现象。接着,基于模型试验结果,对钻井船月池附加阻力进行了回归分析,提出了一种计算“晃荡”模式下月池附加阻力的简化方法。最后,研究了阶梯型月池和栅格减阻板两种减阻方式,用试验方法检验了其减阻效果,提出了一种能够有效减小月池附加阻力的栅格型装置,并申报了国家专利。
[Abstract]:Because of the operation demand, the drilling ship will set up the opening of the lunar pool near the midship, which will bring adverse influence to the navigation resistance performance. However, the research on the increase of the resistance caused by the lunar pool in China is still in its infancy. Based on this, combined with the National Development and Reform Commission "3000 meters Deepwater drilling ship Design and Construction key Technology Research and industrialization", the method of numerical calculation and model test is used to study the resistance performance of drilling ship. Firstly, the steady and unsteady CFD simulation methods of viscous flow field of drilling ship with lunar pool are studied. The steady CFD simulation of the same drilling ship with four different month ponds is carried out and compared with the experimental results. The results show that the resistance predicted by the steady CFD method is effective when the water is not oscillating intensely at low speed and small at high speed. The unsteady CFD simulation of the same drilling vessel with the straight wall lunar pool and the stepped lunar pool is carried out. The results show that the unsteady method can take into account the influence of the unsteady motion of the water body in the lunar pool on the resistance, so the results are more accurate. Based on the results of CFD simulation, the cause of additional resistance of lunar pool is analyzed. Secondly, the additional resistance of the lunar pool of drilling ship is studied experimentally. The model test was carried out in the circulating flume laboratory of Shanghai Jiaotong University. The effects of different moon pond types, scales and draught on the additional resistance of the lunar pool were studied. The results show that different oscillation modes can be observed in the same month at different speeds, but when the ratio of opening length of draught to lunar pool is less than 0.4, it is more likely to be "sloshing" mode, and under two oscillation modes, The additional drag of the lunar pool is linearly related to the amplitude of water oscillation in the lunar pool, and the fluid in the lunar pool will maintain the oscillation mode of the same frequency within a certain speed range, that is, the phenomenon of "frequency locking" exists. Then, based on the model test results, the additional resistance of the lunar pool of drilling ship is regressed, and a simplified method for calculating the additional resistance of the "sloshing" mode next month is proposed. Finally, two kinds of drag reduction methods, ladder lunar cell and grid drag reducing plate, are studied, their drag reduction effect is tested by test method, a grid type device which can effectively reduce the additional resistance of lunar pool is put forward, and the national patent is applied.
【学位授予单位】：中国舰船研究院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U674.38

【共引文献】