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1.
风力机叶片翼型气动特性数值模拟   总被引:1,自引:0,他引:1  
针对NACA63-215翼型绕流流动建立了二维可压缩湍流模型,利用商业软件NU-MECA进行了相应的数值模拟计算.湍流粘度分别采用基于RANS的Spalart-Allmaras和Baldwin-Lomax两种湍流模型来处理,得出了雷诺数为3×106时,翼型NACA63-215的升力系数和阻力系数随来流攻角的变化关系及压力分布图,并与试验数据进行对比.研究结果表明:Spalart-All-maras湍流模型比Baldwin-Lomax湍流模型在预测翼型失速后气动性能方面更加有效,Spalart-Allmaras湍流模型在大攻角下较易收敛且计算出的翼型气动性能与试验值更接近.  相似文献   

2.
基于CFD的拖式吊舱推进器斜流状态下数值模拟   总被引:2,自引:0,他引:2  
采用FLUENT软件计算了某拖式吊舱推进器在直航以及斜流状态下的水动力性能.采用滑移面网格方法以模拟桨叶、支架、以及舱体之间的非定常干扰.文中首先计算了直航时不同进速系数下的桨叶推力系数、扭矩系数,并与实验结果进行了对比.计算了在不同斜流角(15°、30°、45°)、不同载荷系数时桨叶本身的推力系数、扭矩系数、侧向力系数与直航时(0°)的比较.文中还讨论了支架、舱体在直航以及不同斜流角时的侧向力问题,并将其大小与桨叶本身产生的侧向力进行了比较,部分计算结果与已有的实验值进行了比较、分析.  相似文献   

3.
为探索一种新型侧后结合进气装置在船舶行驶过程中受不同风向影响下的性能,应用三维数值模拟方法结合标准k-ε模型,采用多面体网格在保证计算精度情况下得出两侧百叶窗关键气动参数的分布规律,并对比分析了不同风向下外流场结构的变化情况。计算结果表明,在保证两侧百叶窗进气流量相仿时侧向一侧气动参数变成正弦分布关系,变化幅度明显高于后向一侧,而后向一侧气动参数分布规律性较差但气动差异性小,而百叶窗口旋涡强度较高。  相似文献   

4.
为推进无人帆船在海洋环境保护和资源勘测等方面的应用,为一款海上自动航行帆船设计了风帆结构,并进行气动性能分析。建立无襟翼帆、分离式襟翼帆和嵌入式襟翼帆3种翼帆模型,通过Fluent软件进行计算流体力学(CFD)计算分析,比较3种风帆的气动性能,分析变角度襟翼帆对风帆气动性能和对帆船推力提升理论的影响规律。结果表明,嵌入式襟翼帆对无人帆船风帆整体的气动性能具有提升的作用;随着襟翼帆偏转角的增大,风帆的升力系数和升阻比随之增大、帆船的推力系数明显增强,对帆船性能的提升具有较优的影响,促进无人帆船在推力提升方面的研究。  相似文献   

5.
本文借助STAR-CCM+软件对考虑浅水效应的智能技术试验船回转操纵性进行数值模拟研究。首先对无界流场中智能技术试验船的流体动力性能评估,并且与试验结果对比验证了计算方法的准确性;在此基础上,通过改变智能技术试验船与池底的垂向距离,模拟不同浅水工况下智能技术试验船回转操纵性能。数值模拟结果表明,浅水效应下智能技术试验船侧向力系数显著增大,对应的偏航力矩系数亦有所增加。相关结论可为智能技术试验船浅水航行时安全性能提供指导。  相似文献   

6.
王伟吉  周少伟  陈汝刚 《船舶工程》2012,(Z2):60-62,120
利用数值模拟与试验验证相结合的方法对双列V型惯性汽水分离器性能进行了研究,得到了不同叶片间距条件下双列V型惯性汽水分离器的气动性能以及分离效率特性。选取特定的叶片间距的试验模型在专门风洞试验台上进行了气动性能试验研究,试验结果与数值模拟结果吻合性良好,研究结果可为惯性汽水分离器的性能研究与设计优化提供参考。  相似文献   

7.
基于滑移网格技术计算螺旋桨水动力性能研究   总被引:2,自引:0,他引:2  
张漫  黎胜 《船海工程》2013,(5):25-29
基于RANS方程的CFD软件数值模拟螺旋桨定常和非定常的水动力性能.定常计算采用多重参考系MRF模型,分别采用标准k-ε的湍流模型,RNG k-ε湍流模型和Reliable k-ε湍流模型模拟在不同进速系数时的推力系数和转矩系数.将模拟的数值结果与试验值相比较,计算结果表明,采用Reliable k-ε湍流模型计算出的推力系数与转矩系数与试验值基本吻合,并以该结果为初始场,通过滑移网格技术,采用单机并行计算螺旋桨非定常水动力性能.相较于定常计算结果更加接近试验值,说明滑移网格技术具有更高的精准度,更加适用于计算螺旋桨的水动力性能.  相似文献   

8.
本文简要介绍了我所承担的大型石化工程项目--从美国进口的裂解气压缩机增容改造的技术途径、设计方法、气动性能试验及其在实际工程中的应用效果。  相似文献   

9.
本文介绍了一种展弦比为1的环量控制舵翼在零攻角下的水动力性能试验,试验模型是安装有尾缘喷流圆柱的NACA0015截尾方形舵。试验结果表明,随喷流动量系数的增加,升力系数显著上升,为减小阻力,在模型尾缘圆柱上开了一排V形槽,开槽后的模型阻力有不同程度的降低,并用喷流动量系数越大,减阻减大。开槽的另一个效果是使喷流失速推迟。  相似文献   

10.
通过试验。对防波堤-码头结构的波压力进行研究。比较了不同堤顶宽度时波压力的变化。并根据试验得出了相对波浪传播距离b/L和波压力折减系数K的经验曲线,可供类似的防波堤-码头结构的波压力计算参考。  相似文献   

11.
针对软帆形状随帆面上下压力分布改变而改变的特点,基于涡层分布面元法原理,总结前人研究经验,提出一种可靠的数值模拟方法,编制计算程序,对低攻角情况下二维弓型薄翼软帆在不可压缩、理想流体中的空气动力特性进行数值模拟,结果表明:该方法在低攻角下的模拟结果与试验值吻合良好.这一结果对于进一步开展软帆空气动力特性的数值预报和理论分析研究具有重要参考价值.  相似文献   

12.
孙寒冰  昝立儒  孙志远  邹劲 《船舶》2019,30(1):17-24
为准确分析客滚船在不同风向角下的流场分布,基于PIV技术研究了某型客滚船在25m/s风速下,5个不同风向角的风阻变化和流场分布;利用PIV技术得出某型客滚船纵向、横向以及水平方向的空气流场特性。结果表明:随着风向角的增加,纵向风轴阻力和横向侧向力呈"抛物线"规律变化,偏航力矩呈"正弦曲线"分布,并存在两个方向相反的阻力峰。利用PIV流场分布图与常规测力试验的风阻曲线对客滚船风阻流场进行分析研究,所得结果可为以后的CFD计算验证以及后期风阻优化提供参考依据。  相似文献   

13.
The exploration for renewable and clean energies has become crucial due to environmental issues such as global warming and the energy crisis. In recent years,floating offshore wind turbines(FOWTs) have attracted a considerable amount of attention as a means to exploit steady and strong wind sources available in deep-sea areas. In this study, the coupled aero-hydrodynamic characteristics of a spar-type 5-MW wind turbine are analyzed. An unsteady actuator line model(UALM) coupled with a twophase computational fluid dynamics solver naoe-FOAM-SJTU is applied to solve three-dimensional Reynolds-averaged NavierStokes equations. Simulations with different complexities are performed. First, the wind turbine is parked. Second, the impact of the wind turbine is simplified into equivalent forces and moments. Third, fully coupled dynamic analysis with wind and wave excitation is conducted by utilizing the UALM. From the simulation, aerodynamic forces, including the unsteady aerodynamic power and thrust, can be obtained, and hydrodynamic responses such as the six-degrees-of-freedom motions of the floating platform and the mooring tensions are also available. The coupled responses of the FOWT for cases of different complexities are analyzed based on the simulation results. Findings indicate that the coupling effects between the aerodynamics of the wind turbine and the hydrodynamics of the floating platform are obvious. The aerodynamic loads have a significant effect on the dynamic responses of the floating platform, and the aerodynamic performance of the wind turbine has highly unsteady characteristics due to the motions of the floating platform. A spar-type FOWT consisting of NREL-5-MW baseline wind turbine and OC3-Hywind platform system is investigated. The aerodynamic forces can be obtained by the UALM. The 6 DoF motions and mooring tensions are predicted by the naoe-FOAM-SJTU. To research the coupling effects between the aerodynamics of the wind turbine and the hydrodynamics of the floating platform, simulations with different complexities are performed. Fully coupled aero-hydrodynamic characteristics of FOWTs, including aerodynamic loads, wake vortex, motion responses, and mooring tensions, are compared and analyzed.  相似文献   

14.
自升式钻井平台风载荷试验研究   总被引:1,自引:1,他引:0  
陈刚  汪怡  黄曌宇 《船舶工程》2012,34(2):74-75
由于风载荷的计算方法不准确,基于自主设计的自升式钻井平台,首次在国内风洞实验室进行了平均风静力的实验研究。首先根据模型设计相似性要求对包括钻井平台的风载荷进行了模拟实验,主要通过气动测量系统获得相关数据,然后与根据规范的计算结果进行了对比分析,最后建议对计算分析方法进行修正,为钻井平台优化设计奠定了基础。  相似文献   

15.
Although the upwind configuration is more popular in the field of wind energy, the downwind one is a promising type for the offshore wind energy due to its special advantages. Different configurations have different aerodynamic performance and it is important to predict the performance of both downwind and upwind configurations accurately for designing and developing more reliable wind turbines. In this paper, a numerical investigation on the aerodynamic performance of National Renewable Energy Laboratory(NREL) phase VI wind turbine in downwind and upwind configurations is presented. The open source toolbox Open FOAM coupled with arbitrary mesh interface(AMI) method is applied to tackle rotating problems of wind turbines. Two 3D numerical models of NREL phase VI wind turbine with downwind and upwind configurations under four typical working conditions of incoming wind velocities are set up for the study of different unsteady characteristics of the downwind and upwind configurations, respectively. Numerical results of wake vortex structure, time histories of thrust, pressure distribution on the blade and limiting streamlines which can be used to identify points of separation in a 3D flow are presented. It can be concluded that thrust reduction due to blade-tower interaction is small for upwind wind turbines but relatively large for downwind wind turbines and attention should be paid to the vibration at a certain frequency induced by the cyclic reduction for both configurations. The results and conclusions are helpful to analyze the different aerodynamic performance of wind turbines between downwind and upwind configurations, providing useful references for practical design of wind turbine.  相似文献   

16.
针对全直桩码头在水平力作用下相对于叉桩码头易产生转动的特点,分析全直桩码头在水平方向转动刚度的计算方法,推导得出考虑转动刚度影响的全直桩码头水平力分配的计算公式。结合工程算例,分别计算了在横向水平力作用下3种宽长比的全直桩码头的转动刚度及各横向排架的水平力分配系数,并与有限元法、规范法的计算结果进行比较。结果表明,全直桩码头宽长比越大,码头转动刚度越大,各排架的水平力分配系数越均匀;本文公式的计算结果和有限元结果吻合较好,随着码头转动刚度增大,本文公式计算值与规范值相差增大,最大水平力分配系数最多相差22%。  相似文献   

17.
针对风对结构物的作用问题,现行规范与计算方法虽能较准确估算风的直接作用力,但可能忽视间接作用力而使估算不足。以二维典型浮体结构为研究对象,采用物理模型试验方法,分析静水条件恒定风和2种不同类型谱的随机风作用下的风荷载。结果表明,API谱随机风所产生的作用力大于Davenport谱随机风的作用力;不同时距的平均风速对浮体结构的荷载影响试验结果差异较大,应引起工程设计人员的充分注意。  相似文献   

18.
In order to achieve safe navigation, it is important to be able to understand and calculate the effects of an external force on the maneuvering behavior of a ship. This paper analyzes the course stability and yaw motion of a ship traveling under steady wind conditions. A course stability criterion and approximate formulae for the yaw motion in steady wind, including the aero/hydrodynamic force derivatives for the ship, are derived. To confirm the reliability of the criterion and formulae, they were used to investigate a pure car carrier in steady wind. The results of this investigation revealed that course instability appears in the head and following wind directions, mainly under the influence of aerodynamic derivatives with respect to the yaw restoring forces. However, this course instability can be reduced by applying steering control. For winds ranging from head winds to beam winds, yaw oscillation appears when the period is relatively long and the damping is small. The analytical formulae derived here can be used to gain a better understanding of ship maneuvering behavior in steady wind.  相似文献   

19.
岸边集装箱起重机抗风性能设计是不可缺少的控制性环节。本文对65t-65m岸边集装箱起重机风洞试验的模型进行了计算流体动力学(CFD)数值模拟。通过计算几个典型的风向角和风速工况下起重机风洞试验模型,得到了丰富的流场及压力场信息,并绘制了速度分布和压力分布图。与风洞试验的数值对比,所得误差较小,说明使用CFD数值模拟的方法计算岸边集装箱起重机风载荷是可行的。  相似文献   

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