共查询到19条相似文献,搜索用时 187 毫秒
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通过交流阻抗和动电位极化的方法,研究了我院自行设计的高阻尼螺旋桨材料CuAlBe合金在人工海水中的耐蚀性能。研究结果表明:新型减振降噪的高阻尼CuAlBe合金在人工海水中耐蚀性能优于常用螺旋桨材料ZHMn55-3-1;而在阳极极化条件下耐蚀性优于耐海水腐蚀性能优良的ZQA112-8-3-2螺旋桨材料,具有良好的应用前景。 相似文献
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对高强度,高阻尼,耐海水腐蚀的螺旋桨材料-CuAlBe合金进行了焊接性对比试验研究,试验结果表明:CuAlBe合金具有良好的可焊性,经焊接后的合金仍保持原有的良好综合性能,这对所试制的螺旋桨材料具有重要的实际应用意义。 相似文献
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通过交流阻抗和动电位极化的方法,研究了我院自行设计的高阻尼螺旋桨材料CuAlBe合金在人工海水中的耐蚀性能.研究结果表明新型减振降噪的高阻尼CuAlBe合金在人工海水中耐蚀性能优于常用螺旋桨材料ZHMn55-3-1;而在阳极极化条件下耐蚀性优于耐海水腐蚀性能优良的ZQAl12-8-3-2螺旋桨材料,具有良好的应用前景. 相似文献
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螺旋桨用高阻尼合金降噪效果试验研究 总被引:1,自引:0,他引:1
本文介绍了一种新型的高强度、高阻尼、耐腐性优良的螺旋桨专用合金在降噪效果方面的试验研究成果。试验结果表明:用这种合金制作舰船螺旋桨,确能有效抑制唱音(共振引起的异常噪声),有明显的降噪效果。 相似文献
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[目的]船舶复合材料螺旋桨比传统金属合金螺旋桨刚度低,在流固耦合作用下桨叶变形会对水动力和噪声性能带来显著影响,在开展复合材料螺旋桨模型试验时需予以特殊考虑。[方法]采用量纲分析方法,建立复合材料螺旋桨水动力与噪声性能的特殊相似关系及其换算方法。根据复合材料螺旋桨模型加工实物及其作用特点,分析可满足模型试验要求的特殊测试技术。[结果]结果表明,复合材料螺旋桨模型试验在满足金属合金螺旋桨模型试验的相似关系外,仍需满足桨叶水动力变形的相似关系。[结论]不同于传统金属合金螺旋桨,复合材料螺旋桨模型试验需获取螺旋桨的静态型值、力学性能和桨叶动态变形等信息,以此选择合理的螺旋桨试验模型缩比尺度及其材料;同时,试验中除要求保持模型与实尺度螺旋桨的无量纲进速系数相同外,还需满足刚度特性及叶梢马赫数的组合相似度。 相似文献
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阻尼合金在船舶机械振动隔离中的应用研究 总被引:4,自引:0,他引:4
为了解决船舶动力机械向船体结构的振动传递问题,目前主要采取隔振措施。由于机械机座和体的非刚性,隔振效果受到了一定的影响。为此,作者提出用阻尼合金的材料作为中间机座,利用阻尼合金的碱性能来降低船舶动力机械传递至船体的结构噪声。本文采用动力机械和船体结构的模型装置测试了阻尼合金机座的减振特性。测试结果表明,减振效果较好,特别是在高频下的船体结构振支明显地减小。 相似文献
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《船舶与海洋工程学报》2020,(1)
Despite their high manufacturing cost and structural deficiencies especially in tip regions, highly skewed propellers are preferred in the marine industry, where underwater noise is a significant design criterion. However, hydrodynamic performances should also be considered before a decision to use these propellers is made. This study investigates the trade-off between hydrodynamic and hydroacoustic performances by comparing conventional and highly skewed Seiun Maru marine propellers for a noncavitating case.Many papers in the literature focus solely on hydroacoustic calculations for the open-water case. However, propulsive characteristics are significantly different when propeller-hull interactions take place. Changes in propulsion performance also reflect on the hydroacoustic performances of the propeller. In this study, propeller-hull interactions were considered to calculate the noise spectra.Rather than solving the full case, which is computationally demanding, an indirect approach was adopted; axial velocities from the nominal ship wake were introduced as the inlet condition of the numerical approach. A hybrid method based on the acoustic analogy was used in coupling computational fluid dynamics techniques with acoustic propagation methods, implementing the Ffowcs Williams-Hawkings(FW-H) equation. The hydrodynamic performances of both propellers were presented as a preliminary study.Propeller-hull interactions were included in calculations after observing good accordance between our results, experiments, and quasi-continuous method for the open-water case. With the use of the time-dependent flow field data of the propeller behind a nonuniform ship wake as an input, simulation results were used to solve the FW-H equation to extract acoustic pressure and sound pressure levels for several hydrophones located in the near field. Noise spectra results confirm that the highest values of the sound pressure levels are in the low-frequency range and the first harmonics calculated by the present method are in good accordance with the theoretical values. Results also show that a highly skewed propeller generates less noise even in noncavitating cases despite a small reduction in hydrodynamic efficiency. 相似文献
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舰艇螺旋桨水下噪声预测 总被引:5,自引:0,他引:5
螺旋桨空化噪声是舰艇最主要的辐射噪声源。文章分析了螺旋桨噪声平坡形谱曲线的特点,给出源声级谱级曲线的衰减指数值,分析了特征频率和峰值谱级的影响因素。由螺旋桨空化状态下两个特征航速对应的部分频段内的噪声谱级计算式拟合得到水面舰船螺旋桨空化后任意可达航速下的噪声谱曲线。结合叶梢周向速度一定时特征频率处谱级与螺旋桨直径的函数关系和频率一定时叶梢周向速度变化引起的特征频率处谱级变化量,得到潜艇螺旋桨无空化状态下特征频率处谱级,在空化状态下,还需要加上螺旋桨进入尖锐谱峰区和转速进一步升高引起的声级增加量,从而得到了潜艇在任意航态下整个频带内螺旋桨噪声谱级的计算式。利用已有数据对计算式进行了检验,计算声级误差小于4dB。计算中用到的叶梢初生空泡数和判定是否出现窄带调噪声要通过空泡筒试验确定。 相似文献
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船用螺旋桨的应用与发展趋势 总被引:2,自引:0,他引:2
回顾了船用螺旋桨的历史演化过程。对不同船舶工作条件下的一些特种螺旋桨特点进行了分析,重点介绍了几种新型螺旋桨的构造与应用,指出了今后螺旋桨设计的发展方向。 相似文献
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Nai-Xian Lu Rickard E. Bensow Göran Bark 《Journal of Marine Science and Technology》2014,19(2):197-214
This paper deals with numerical simulations of the cavitating flow around two highly skewed propellers operating in open water and mounted on an inclined shaft. The aim of the study is to check the ability of our numerical method in distinguishing the variation in flow features resulting from different blade designs. Moreover, a secondary aim is also to improve the knowledge about the physics that control the growth and collapse of cavitation, and hence also the generation of cavitation noise and erosion on this type of propellers. The investigation is based on incompressible large eddy simulation (LES) in combination with a volume-of-fluid implementation to represent the two phases of liquid and vapour, and a transport equation-based method for the mass transfer between the phases. High-speed video recordings from experiments were made available for comparison. The simulations demonstrate that the current method makes it possible to analyse the main difference in flow features caused by modest design alternation. Furthermore, with suitable grid resolution, LES is demonstrated to be capable of capturing the mechanisms that are important in the cavitation development, and that numerical simulation is a reliable supplement to experiments in advanced propeller design. 相似文献