共查询到17条相似文献,搜索用时 78 毫秒
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毂帽鳍作为一种新型的船用节能装置,合理地安排其在桨后的位置,能明显提升螺旋桨的推进效率,因此,有必要对毂帽鳍的节能效果进行研究。采用计算流体动力学方法,对毂帽鳍的敞水性能进行模拟。通过改变鳍叶在桨后的各个参数,分析其尾流的变化,以及各重要剖面处的压力分布等情况。模拟结果表明:鳍叶的不同安装角位置对桨的效率变化有明显的影响,而轴向位置的改变则对其效率的提高影响不大。通过观察尾流分布及压力分布图,可以直观地看出鳍叶的主要功效是产生与螺旋桨转向相同的扭矩,同时使尾流速度降低从而削弱乃至消除毂涡。 相似文献
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毂帽鳍是一种简单、有效并且经过实践检验的节能装置,目前应用十分广泛.在归纳已有的毂帽鳍设计方法基础上,提出了螺旋桨毂帽鳍设计新方法,给出一例设计结果,并与经验设计结果进行了对比. 相似文献
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Takafumi Kawamura Kazuyuki Ouchi Takeo Nojiri 《Journal of Marine Science and Technology》2012,17(4):469-480
Computational fluid dynamics (CFD) analyses of propeller boss cap fins (PBCF) were carried out for two different propellers at model and full scale Reynolds numbers with two different inflow conditions. Computations corresponding to the reverse propeller open test (POT) experiment were confirmed to be in a good agreement with the measurement. The results of computations at different conditions have shown that increased Reynolds number and presence of hull wake both positively influence the effects of PBCF. Due to the combined effect of the Reynolds number and the wake, the gain in the propeller efficiency at the full scale condition was found to be significantly larger than that at the model test condition. The detailed investigation of the results suggested that the fin drag becomes smaller and the reduction of the boss drag becomes larger at the full scale condition. However, the predicted gain is still smaller than the values reported in the sea trial and logbook analysis. The remaining gap may be attributed to the difference in the estimated and actual wake distribution or to other factors such as interactions with hull and rudder, surface roughness, unsteadiness and hub vortex cavitation. 相似文献
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船舶推进节能技术研究与进展 总被引:7,自引:2,他引:7
随着船舶燃油价格的上涨,船舶节能技术得到了广泛的关注,本文旨在介绍国内外船舶推进与节能方面的研究与进展。其中包括优秀船型的研究、开发附加流体水动力节能装置、新型高效推进器以及一些特殊船舶节能技术的研究。重点介绍了非对称尾船型、双尾鳍船型、可调距螺旋桨、对转螺旋桨、桨后自由旋转助推叶轮、舵附推力鳍以及一些特殊船舶推进节能装置的研究与应用等。 相似文献
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Numerical simulation is investigated to disclose how propeller boss cap fins (PBCF) operate utilizing Reynolds-averaged Navier-Stokes (RANS) method. In addition, exploration of the influencing mechanism of PBCF on the open water efficiency of one controllable-pitch propeller is analyzed through the open water characteristic curves, blade surface pressure distribution and hub streamline distribution. On this basis, the influence of parameters including airfoil profile, diameter, axial position of installation and circumferential installation angle on the open water efficiency of the controllable-pitch propeller is investigated. Numerical results show: for the controllable-pitch propeller, the thrust generated is at the optimum when the radius of boss cap fins is 1.5 times of propeller hub with an optimal installation position in the axial direction, and its optimal circumferential installation position is the midpoint of the extension line of the front and back ends of two adjacent propeller roots in the front of fin root. Under these optimal parameters, the gain of open water efficiency of the controllable-pitch propeller with different advance velocity coefficients is greater than 0.01, which accounts for approximately an increase of 1%-5% of open water efficiency. 相似文献
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