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为了解决全回转推进器螺旋桨的单向流固耦合问题,实现螺旋桨桨叶结构强度精确评估,文章基于计算流体力学和有限元法开展了螺旋桨桨叶的结构强度计算方法研究,重点探讨了桨叶表面随机分布压力从流体域到固体域的转换技术。在此基础上,文中提出了桨叶固液交界面上水动力载荷的转换方法,详细研究了插值加权系数和有限元网格尺寸对桨叶结构强度计算精度的影响规律,给出了适用于桨叶强度评估的插值加权系数和单元网格尺寸选取原则。最后,该文以5000 kW级全回转推进器螺旋桨为例,开展了桨叶结构强度数值计算和安全评估,获得了桨叶的应力和变形分布规律,整体上建立了全回转推进器螺旋桨桨叶结构强度评估方法,可为大功率全回转推进器螺旋桨设计提供借鉴和参考。 相似文献
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《船舶力学》2016,(9)
为了解决全回转推进器螺旋桨的单向流固耦合问题,实现螺旋桨桨叶结构强度精确评估,文章基于计算流体力学和有限元法开展了螺旋桨桨叶的结构强度计算方法研究,重点探讨了桨叶表面随机分布压力从流体域到固体域的转换技术。在此基础上,文中提出了桨叶固液交界面上水动力载荷的转换方法,详细研究了插值加权系数和有限元网格尺寸对桨叶结构强度计算精度的影响规律,给出了适用于桨叶强度评估的插值加权系数和单元网格尺寸选取原则。最后,该文以5 000 k W级全回转推进器螺旋桨为例,开展了桨叶结构强度数值计算和安全评估,获得了桨叶的应力和变形分布规律,整体上建立了全回转推进器螺旋桨桨叶结构强度评估方法,可为大功率全回转推进器螺旋桨设计提供借鉴和参考。 相似文献
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采用有限元法分析船用螺旋桨桨叶强度已非常广泛。有限元法是当前获得桨叶应力分布详尽而又可靠的最好方法,本文所叙述的是用颇为简单的三维元对桨叶静态应力进行计算。由于叶片近毂体部位为三维特性,因此三元最好选成板单元或毂单元。从另一方面来说,这也便于把所考虑的结构推广到穀部。本文提出的这些计算结果均与用应变仪在各实船桨叶上所测得的结果进行了对比。 相似文献
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大侧斜对转螺旋桨水动力及桨叶应力数值计算 总被引:1,自引:0,他引:1
《舰船科学技术》2013,(6):11-14
对转桨采用大侧斜形式能降低螺旋桨的线谱噪声,但同时也会降低叶片的强度和刚度,工程应用中需要对其强度进行校核。本文基于不可压缩流体"雷诺时均N-S方程+RSM湍流模型",采用多重参考系模型处理多旋转区域耦合问题,得到了螺旋桨表面压力分布;应用有限元(FEA)分析方法对叶片进行分析,得到叶片应力分布与变形量等参数。通过对大侧斜对转螺旋桨水动力及桨叶应力数值计算,为螺旋桨设计提供理论依据,具有一定的工程意义。 相似文献
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以DTMB4381桨为研究对象,通过在桨叶表面布置加速度传感器,采用锤击法测得桨叶的固有频率.探究螺旋桨直径、螺旋桨安装位置、敲击工具和敲击位置对桨叶固有频率测量结果的影响.试验结果表明:螺旋桨的固有频率与其缩尺比呈反比;改变螺旋桨的安装位置会对其固有频率测量结果产生微小影响;不同的敲击工具激发桨叶固有频率的能力不同;改变敲击位置会使桨叶固有频率测量结果发生明显改变. 相似文献
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针对复合材料螺旋桨流固耦合效应显著的特点,本文通过CFD计算复合材料螺旋桨所受水动力载荷,应用有限元方法计算复合材料桨叶结构响应,建立双向流固耦合数值计算方法,研究不同进速系数工况下刚性和复合材料螺旋桨的水动力性能与结构特性。研究结果表明:相较于刚性螺旋桨,复合材料螺旋桨通过弯扭耦合变形实现螺距角与攻角自适应匹配,进而提高推进效率并降低功率损耗;复合材料桨叶的最大总变形和最大等效应力随来流速度的增大而减小,随旋转速度的增大而增大。基于蔡-吴准则对复合材料螺旋桨的失效行为进行判断,蔡-吴失效系数随进速系数的增大而降低,失效区域更容易出现在桨叶叶梢处。 相似文献
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螺旋桨设计参数对桨叶片空泡性能的影响分析 总被引:1,自引:0,他引:1
文章基于扰动速度势面元法建立了在均流条件下螺旋桨桨叶片空泡数值预报方法,空泡模型采用压力恢复闭合模型。通过对5600TEU集装箱船螺旋桨空泡的数值预报,以及与试验结果的比较,验证了该方法的可行性。该方法能够较为快速准确地预报螺旋桨桨叶片空泡,可用于分析参数对螺旋桨空泡性能的影响,为抑制螺旋桨空化设计提供基础。在此基础上重点分析了桨叶侧斜、纵倾以及桨叶剖面型式对螺旋桨空泡性能的影响,计算表明加大侧斜能够减少空泡面积,空泡向外半径偏移;桨叶剖面的设计对空泡性能影响较大,优化设计桨叶剖面可以有效减少空泡面积,提高螺旋桨抗空化能力;纵倾向压力面弯曲的分布形式可以改善梢部的压力分布,减少叶梢附近空泡长度,从而可望减少由空泡引起的脉动压力。 相似文献
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采用分离涡模拟(DES)方法对多工况下螺旋桨的尾流场特性及尾涡结构进行数值研究,应用滑移网格技术完成螺旋桨敞水试验模拟,采用Spalart-Allmaras湍流模型封闭N-S方程组。数值计算结果显示:采用DES方法得到的水动力特性结果与模型试验结果吻合度高,DES方法能够较好地捕捉到螺旋桨尾流场中复杂的尾涡结构,螺旋桨不同桨叶产生的梢涡之间的自诱导和相互诱导作用引起尾涡结构形态变化,4叶桨梢涡结构之间会产生2次融合重组,毂涡振荡与梢涡演化之间存在相互干扰作用,不同进速系数下尾涡演化规律基本一致。 相似文献
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Bu-Geun Paik Jin Kim Young-Ha Park Ki-Sup Kim 《Journal of Marine Science and Technology》2007,12(2):72-82
The vortex structure of the wake behind a marine propeller was investigated in terms of loading variation by using particle
image velocimetry. One hundred and fifty instantaneous velocity fields were ensemble averaged to study the spatial evolution
of the wake and the behavior of the tip vortices in the region ranging from the trailing edge to one propeller diameter downstream.
The trailing vorticity was found to be related to the radial velocity jump, and the viscous wake was affected by the boundary
layers developed on the blade surfaces. A vortex identification method using the swirling strength was employed to extract
the location of the tip vortex. The loading on the blade made a clear difference to the contraction angles. Slipstream contraction
occurred in the very near wake region, and unstable oscillation occurred because of reduced interaction between the tip vortex
and the wake sheet behind the maximum contraction point for each loading condition. The maximum tangential velocity around
the tip vortex center revealed the average radius of its core, which was used for calculating the vortex strength. Additionally,
variation of the average radius of tip vortices with the change of blade loading was related to vortex tube stretching in
the wake region. The nearly constant vortex strength continued up to one diameter downstream for light loading and design
loading conditions. 相似文献
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螺旋桨低频流噪声模拟方法研究 总被引:2,自引:0,他引:2
针对DTMB P4119螺旋桨在进速比为0.833时的流噪声进行研究,探讨螺旋桨低频流噪声数值模拟方法。首先采用大涡模拟方法模拟螺旋桨的非稳态流场,然后求解K-FWH方程预测低频流噪声。将计算得到的推力系数和扭矩系数与实验值比较,验证流场模拟的正确性。从流场仿真结果可以看出,螺旋桨表面存在连续的涡脱落现象。声场计算的结果表明:离散噪声远大于宽带噪声;宽带噪声主要由螺旋桨表面的涡脱落引起,宽带噪声引起螺旋桨近场总声压级的周向波动;在同一半径处总声压级沿轴向逐渐减小,在同一平面内总声压级沿径向先增加后减小。 相似文献
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本文给出了螺旋桨周围流场的预报方法及其数值计算结果。本方法以具有涡分布和源汇分布的升力面来构造螺旋桨对流场的状动。升力面取奖叶拱弧面。根据桨叶表面流动不穿透条件解出升力面奇点后,然后再求它们对流场的扰动。敞水螺旋桨的脉动速度计算结果与试验结果吻合良好。 相似文献
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本文基于计算流体力学(CFD)方法,对多重参考系模型(MRF)及滑移网格模型(SM)在计算螺旋桨水动力性能时的差异进行了探讨。将以上两种模型应用到4381螺旋桨的水动力性能计算中,首先将计算得到的推力系数及转矩系数与试验数据进行了对比,考察了两种计算模型对螺旋桨的敞水性能的预测情况,并进一步对两种模型计算得到的螺旋桨盘面的速度场、桨叶的压力分布、桨后涡量云图等进行了对比分析。计算结果表明,滑移网格模型相较于多重参考系模型,对螺旋桨的推力系数的模拟结果误差更小,扭矩系数方面,两种模型的模拟结果相差不大;对于进速系数较大时,两种模型模拟得到的压力分布及速度分布较为相似,但对于高负荷情况,滑移网格模型可以更好地捕捉桨叶的压力分布及桨盘面处的速度分布情况;进速系数较小时,多重参考系模型可以模拟出涡结构的发散现象,而滑移网格模型可以更好的在高进速系数情况下捕捉到梢涡结构。 相似文献
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A finite-element method coupled with analysis of a noncavitating lifting surface was used to assess the performance of a marine
propeller, including the thrust, torque, efficiency coefficients, and deflections. The formulation used displacements as unknowns
in the structural part and the strength of the vortex as unknowns in the fluid part. A coupled matrix derived from the Bernoulli
equation and hydrostatic pressure in terms of the strength, of the vortex enforced coupling between the fluid and the structure.
The resulting matrix equation was unsymmetric and nonlinear; a Newton-Raphson procedure was used to solve this equation. The
numerical results were compared with test data; computed and measured values agreed satisfactorily. We also investigated the
effect of blade thickness on the performance and strength of the propeller. We did not consider the fatigue strengh of the
propeller in this analysis. 相似文献
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Yoshihisa Takekoshi Takafumi Kawamura Hajime Yamaguchi Masatsugu Maeda Norio Ishii Koyu Kimura Tadashi Taketani Akihiko Fujii 《Journal of Marine Science and Technology》2005,10(2):70-81
A new method for designing propeller blade sections is presented. A vortex lattice method is used to evaluate the performance and the time-dependent pressure distribution on the blade surface in a non-uniform flow, while efficient optimization algorithms are used to modify the blade sections. Two different designs were carried out in this study. The first was a design to realize a target pressure distribution in a rotating three-dimensional flow. A two-dimensional wing theory was used to obtain the target pressure distribution. The predicted increase in efficiency and the reduction in the cavity volume were confirmed by model experiments. The second was a design to maximize the propeller efficiency. By this method, the propeller efficiency was improved by 1.2% under the constrains of constant thrust and a prescribed margin for face cavitation. 相似文献
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Bu Geun Paik Choung Mook Lee Sang Joon Lee 《Journal of Marine Science and Technology》2005,10(3):123-130
In order to investigate the effects of a free surface on the wake behind a rotating propeller, experiments were carried out in a circulating water channel for two cases: one with an open free surface and one with a closed free surface covered by a rigid plate. Four hundred instantaneous velocity fields were measured using a two-frame particle image velocimetry (PIV) technique at four different blade phases. These were ensemble-averaged to investigate the time-averaged flow structure in the near-wake region. For a surface ship, the flow behind the propeller is influenced by the hull wake and the free surface. The phase-averaged mean velocity fields show the potential wake and the viscous wake formed by the boundary layers developed on the blade surfaces. The interaction between the bilge vortices and the incoming flow along the ship’s hull deforms the wake structure. Tip vortices are generated periodically, and the slipstream contraction occurs in the near-wake region. The free surface was found to affect the axial velocity component and vortex structure behind the propeller. As the flow goes downstream, the tip and trailing vortices dissipate due to turbulent diffusion and active mixing with adjacent vortices. 相似文献