基于大涡模拟的螺旋桨毂帽鳍系统精细流场数值研究

对引起螺旋桨毂帽鳍系统推进性能变化的细节及流动本质问题的研究，有助于对毂帽鳍的节能机理产生新的认识，并为改进该系统的推进性能提供新的思路。通过模型试验和大涡模拟方法对螺旋桨毂帽鳍系统进行了力的测量及精细流场的分析，从能量的角度，分析了毂帽鳍节能机理。数值模拟显示，在毂帽鳍的作用下，在紧邻桨毂后方区域的流速比无毂帽鳍时小且低速区域更广，桨毂后方流体轴向和横向动能均有所减小。由此可知，毂帽鳍通过回收一部分螺旋桨释放在尾流中的动能实现节能；在桨毂后安装一种圆锥形导流帽可避免流动分离，能进一步提高推进系统的整体效率。     

桨毂形状对螺旋桨水动力影响仿真

采用全结构化网格对桨毂进行计算流体动力学(CFD)水动力仿真,验证仿真方法的有效性,研究3种典型桨毂形状对螺旋桨敞水特性、截面压力分布和空化的影响。通过对比分析发现:圆弧形桨毂阻力最小,效率最优,桨毂形状主要影响叶根区域的流动;圆柱形桨毂叶根的压力最小,空化面积最大;圆弧形桨毂的抗空化性能最优。     

桨毂形状对螺旋桨水动力影响仿真

采用全结构化网格对桨毂进行计算流体动力学(CFD)水动力仿真,验证仿真方法的有效性,研究3种典型桨毂形状对螺旋桨敞水特性、截面压力分布和空化的影响。通过对比分析发现:圆弧形桨毂阻力最小,效率最优,桨毂形状主要影响叶根区域的流动;圆柱形桨毂叶根的压力最小,空化面积最大;圆弧形桨毂的抗空化性能最优。     

毂帽鳍的节能机理分析

应用计算流体力学方法(CFD),结合RNG湍流模型和动参考系计算模型(MRF),对普通桨和桨+毂帽鳍的敞水水动力性能进行计算,通过对毂帽鳍及螺旋桨叶片的受力情况进行研究,结合普通桨和桨+毂帽鳍2种情况的桨后尾流场分析,结果表明,桨后毂帽鳍上产生的推力和扭矩有限,桨+毂帽鳍的节能机理主要是利用毂帽鳍削弱了毂涡,改善了桨后流场周向速度,提高了前桨的推力,从而提高了效率。     

毂帽鳍的节能机理分析

应用计算流体力学方法（CFD）,结合 RNG湍流模型和动参考系计算模型（MRF）,对普通桨和桨+毂帽鳍的敞水水动力性能进行计算,通过对毂帽鳍及螺旋桨叶片的受力情况进行研究,结合普通桨和桨+毂帽鳍2种情况的桨后尾流场分析,结果表明,桨后毂帽鳍上产生的推力和扭矩有限,桨+毂帽鳍的节能机理主要是利用毂帽鳍削弱了毂涡,改善了桨后流场周向速度,提高了前桨的推力,从而提高了效率。     

30kn排水型艇大侧斜桨设计研究

本文通过对３０ｋｎ排水型侧斜桨的设计研究，解决了在有设计桨存在的叶根面空泡剥蚀问题，同时也使亲的效率提高了约２％（３叶桨）和６．５％。本研究结果可用于最高航速３０ｋｎ左右的快艇。     

调距桨静态加载试验装置设计

研制了调距桨装置半实物加载试验装置,包括机械加载装置、加载液压系统和电控系统.该试验装置可模拟调距桨装置在实际航行时所受的各种静态载荷.通过试验模拟加载,可获得桨毂毂桥、叶根螺栓等主要零件的应力与加载负荷的关系及分布情况,并可验证理论分析、仿真计算,为叶根螺栓等零件的优化设计提供依据.     

螺旋桨毂帽鳍水动力性能数值分析

为了预报毂帽鳍的水动力性能,采用计箅流体力学软件对粘性流场中毂帽鳍的敞水性能进行计算研究.模拟某型毂帽鳍在不同进速系数下的推力系数、转矩系数、螺旋桨桨叶表面压力分布和桨毂表面速度矢量分布情况等.通过加鳍螺旋桨与母型桨相关计箅结果的对比,得到:在低进速系数情况下,螺旋桨加鳍后使得推力系数上升、转矩系数下降,导致其效率有所增加;同时由于鳍的存在,改变了桨毂处水流的速度分布,使得原先围绕桨毂随螺旋桨方向旋转的水流沿着鳍向桨后运动而不在桨毂处汇集,从而减弱了桨毂涡流.     

螺旋桨毂帽鳍节能装置的数值评估与试验研究

对螺旋桨毂帽鳍装置的节能效果采用粘流CFD数值模拟与模型试验的方法进行了评估.利用CFD数值工具对毂帽鳍的节能机理、螺旋桨与毂帽鳍的相互作用,以及雷诺数对节能效果评估的影响进行了详细研究.研究表明,在将桨毂、毂帽鳍和桨叶看作一个系统来考虑时,才能定量评估出节能效果.毂帽鳍对整个系统总推力影响很小,对总扭矩显著减小,从而效率增加.实型尺度雷诺数下毂帽鳍计算得到的节能效果更高,这间接证实了毂帽鳍实船节能效果可能比模型试验节能效果更显著.     

调距桨桨毂机构静强度的有限元仿真分析

文章对受推力、扭力、扭矩、离心力和螺栓预紧力联合作用下的某型舰船调距桨桨毂机构静强度进行有限元仿真分析。基于ANSYS 12.0软件平台,考虑桨毂部件几何结构及零件间装配接触关系,对桨毂机构整体及零件进行全六面体和六面体与四面体混合有限元建模,研究了桨毂中各零件在正常工况相互作用下的应力大小及分布。重点针对叶根螺栓的实际结构,采用六面体网格分析螺栓有无螺纹区别,证明螺纹的几何特征在强度校核中不能忽略。     

毂帽鳍对调距桨推进效率影响的数值研究(英文)

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.     

基于Boltzmann方法的手动可调螺距桨敞水特性

针对船舶长期服役后出现的船、机、桨不匹配问题,采用Boltzmann方法建立手动可调螺距螺旋桨的数学模型,对手动可调螺距螺旋桨进行敞水特性计算,结果表明:手动可调螺距螺旋桨随着螺距角的增大,其推力、转矩逐渐增大,当进速较小时,桨叶螺距角小的效率高,进速较大时桨叶螺距角大的效率高,并且桨叶螺距角有一定的工作范围,另外随着桨叶螺距的增大,桨叶吸力面低压区逐渐减小,桨叶压力面高压区逐渐增大,叶根及桨毂附近的低压区逐渐减少,手动可调桨发生空化的可能性将降低。     

37500方LEG运输船螺旋桨毂帽鳍设计研究

毂帽鳍是一种通过回收螺旋桨毂涡旋转能量来达到节能效果的船舶桨后节能装置。本文针对我公司承建的37500方LEG运输船,运用CFD软件对粘性流场中毂帽鳍的敞水性能进行了计算研究,着重考察了毂帽鳍的根部螺距角、错位角、直径比及纵向位置等因素对效率的影响,通过多方案优选设计了适用于该船的毂帽鳍方案,并对该方案进行了模型试验验证。结果表明：在螺旋桨工作点时,螺旋桨效率提高了1.26%。考虑到模型试验的尺度效应,在实船应用时其节能效果将更加显著。     

A method for numerical calculation of propeller hydrodynamics in unsteady inflow

The hydrodynamic performance of a propeller in unsteady inflow was calculated using the surface panel method. The surfaces of blades and hub were discreted by a number of hyperboloidal quadrilateral panels with constant source and doublet distribution. Each panel's corner coordinates were calculated by spline interpolation between the main parameter and the blade geometry of the propeller. The integral equation was derived using the Green Formula. The influence coefficient of the matrix was calculated by the Morino analytic formula. The tangential velocity distribution was calculated with the Yanagizawa method, and the pressure coefficient was calculated using the Bonuli equation. The pressure Kutta condition was satisfied at the trailing edge of the propeller blade using the Newton-Raphson iterative procedure, so as to make the pressure coefficients of the suction and pressure faces of the blade equal at the trailing edge. Calculated results for the propeller in steady inflow were taken as initialization values for the unsteady inflow calculation process. Calculations were carried out from the moment the propeller achieved steady rotation. At each time interval, a linear algebraic equation combined with Kutta condition was established on a key blade and solved numerically. Comparison between calculated results and experimental results indicates that this method is correct and effective.     

Experimental study on a model azimuthing podded propulsor in ice

The objective of this study was to investigate the performance of a model azimuthing podded propulsor in ice-covered water. Model tests were carried out with two different depths of cut into the ice (15 and 35 mm), two different ice conditions (presawn and pack ice conditions), and four different azimuthing angles. The depth of cut is the maximum penetration depth of the propeller blade into the ice block. The 0.3-m-diameter model propeller was operated in a continuous ice milling condition. Ice loads were measured by several sensors which were installed in various positions on the model. Six one-axis pancake-style load cells on the top of the model measured the global loads and two six-component dynamometers were installed on the shaft to measure the shaft loads. One six-component dynamometer was attached to the one of the propeller blades inside the hub to measure the blade loads. The pod unit and propeller performance in ice are presented. Ice-related loads, which were obtained when the blade was inside the ice block, are introduced and discussed. During the propeller–ice interaction, a blade can experience the path generated by the previous blade, which is called the shadowing effect. The effects of shadowing, depth of cut, azimuthing angle, and advance coefficient on propulsor performance are presented and discussed.     

大侧斜螺旋桨桨叶应力分析

采用求解RANS方程的方法对某大侧斜螺旋桨敞水流场进行模拟,计算得到的推力系数与力矩系数与试验值有很好的一致性.在此基础上,将计算得到的桨叶水动力载荷、离心力载荷和重力载荷导入有限元模型,求解大侧斜螺旋桨桨叶应力场分布.根据应力场分布特点,可知:桨叶除叶根有应力集中区域外,0.5倍半径靠近随边处还存在应力集中区域;在0.5倍半径桨叶切面处,桨叶压力面应力从导边至随边递增,桨叶吸力面应力从导边至随边存在波动.     

导管剖面设计对导管螺旋桨水动力特性的影响

运用计算流体的方法对导管螺旋桨的叶梢漩涡、螺旋桨周围流场和推力特性进行计算,并且通过组合不同类型的导管对比分析了梢涡的改善方法和推力性能的优化方案.计算结果表明:调整导管螺旋桨中的导管迎角,并延长导管有助于改善导管螺旋桨梢涡的产生和改善桨毂后的尾流,有利于提高导管螺旋桨的稳定性;增大导管迎角并延长导管能够使桨叶上荷载和推力分布更加均匀;在进速系数J=0.4左右,导管螺旋桨性能更优,也更高效.本文结论有助于设计出性能优良的导管螺旋桨.     

面元法预报螺旋桨表面非定常压力分布

本文建立了扰动速度势面元法预报螺旋桨表面非定常压力分布的理论和数值方法。该方法把桨叶和桨毂表面离散为若干四边形双曲面元,每个面元上布置等强度源汇和偶极子分布,螺旋桨尾涡面也离散为布置等强度偶极子的四边形双曲面元。所有的时域参数通过傅里叶级数展开转化为频域参数,使得在时间域内的求解转化为每一谐调阶上的求解。桨叶随边处通过迭代和采用广义逆矩阵方法在每一谐调阶上实现非线性等压库塔条件。桨叶表面非定常压力