期刊文献+
共找到378篇文章
< 1 2 19 >
每页显示 20 50 100
Modeling of Fluid Turbulence Modification Using Two-time-scale Dissipation Models and Accounting for the Particle Wake Effect 被引量:6
1
作者 于勇 周力行 王保国 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2006年第3期314-320,共7页
Presently developed two-phase turbulence models under-predict the gas turbulent fluctuation, because their turbulence modification models cannot fully reflect the effect of particles. In this paper, a two-time-scale d... Presently developed two-phase turbulence models under-predict the gas turbulent fluctuation, because their turbulence modification models cannot fully reflect the effect of particles. In this paper, a two-time-scale dissipation model of turbulence modification, developed for the two-phase velocity correlation and for the dissipation rate of gas turbulent kinetic energy, is proposed and used to simulate sudden-expansion and swirling gas-particle flows. The proposed two-time scale model gives better results than the single-time scale model. Besides, a gas turbulence augmentation model accounting for the f'mite-size particle wake effect in the gas Reynolds stress equation is proposed. The proposed turbulence modification models are used to simulate two-phase pipe flows. It can properly predict both turbulence reduction and turbulence enhancement for a certain size of particles observed in experiments. 展开更多
关键词 turbulence modification two time scale dissipation model wake effect
下载PDF
Triatomic wake effect and the determination of the molecular structure of HD_2^+ from the Coulomb explosion
2
作者 洲森 缪竞威 +3 位作者 廖雪花 缪蕾 袁学东 师免恭 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第11期4840-4845,共6页
A new theoretical model of the triatomic molecular wake effect is proposed and applied to molecular ions D^+3 and HD^+2 while passing through a solid. The wake effects resulting from the reactions of the two similar... A new theoretical model of the triatomic molecular wake effect is proposed and applied to molecular ions D^+3 and HD^+2 while passing through a solid. The wake effects resulting from the reactions of the two similar ions with thin carbon foil are also investigated by using the Coulomb explosion technique. The experimental results are in good agreement with theoretical estimates and the molecular structure of HD^+2 is determined by using the model. 展开更多
关键词 triatomic wake effect Coulomb explosion molecular structure ion HD^+2
下载PDF
Review on Research about Wake Effects of Offshore Wind Turbines
3
作者 Yehong Dong Guangyin Tang +5 位作者 Yan Jia Zekun Wang Xiaomin Rong Chang Cai Qingan Li Yingjian Yang 《Energy Engineering》 EI 2022年第4期1341-1360,共20页
In recent years,the construction of offshore wind farms is developing rapidly.As the wake effect of the upstream wind turbines seriously affect the performance of the downstream wind turbines,the wake effect of offsho... In recent years,the construction of offshore wind farms is developing rapidly.As the wake effect of the upstream wind turbines seriously affect the performance of the downstream wind turbines,the wake effect of offshore wind turbines has become one of the research hotspots.First,this article reviews the research methods of wake effects,including CFD numerical simulation method,wind turbine wake model based on roughness and engineering wake models.However,there is no general model that can be used directly.Then it puts forward some factors that affect the wake of offshore wind turbines.The turbulence intensity in offshore wind fields is lower than that in onshore wind fields.This makes the wake recovery length of offshore wind turbines longer than that of onshore wind turbines.Floating offshore wind turbines are simultaneously disturbed by wind loads and wave loads.Unsteady movement of the platform caused by wave loads.It affects the development and changes of the wake of wind turbines.In this regard,the focus of research on the wake effects of offshore wind farms will be the proposal of accurate prediction models for the wake effects of sea wind farms. 展开更多
关键词 Wind energy offshore wind turbines wake effects offshore wind farms
下载PDF
Modeling of Fluid Turbulence Modification Using Two-time-scale Dissipation Models and Accounting for the Particle Wake Effect 被引量:3
4
作者 于勇 周力行 王保国 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2006年第3X期314-320,共7页
Presently developed two-phase turbulence models under-predict the gas turbulent fluctuation, because their turbulence modification models cannot fully reflect the effect of particles. In this paper, a two-time-scale d... Presently developed two-phase turbulence models under-predict the gas turbulent fluctuation, because their turbulence modification models cannot fully reflect the effect of particles. In this paper, a two-time-scale dis- sipation model of turbulence modification, developed for the two-phase velocity correlation and for the dissipation rate of gas turbulent kinetic energy, is proposed and used to simulate sudden-expansion and swirling gas-particle flows. The proposed two-time scale model gives better results than the single-time scale model. Besides, a gas tur- bulence augmentation model accounting for the finite-size particle wake effect in the gas Reynolds stress equation is proposed. The proposed turbulence modification models are used to simulate two-phase pipe flows. It can prop- erly predict both turbulence reduction and turbulence enhancement for a certain size of particles observed in ex- periments. 展开更多
关键词 TURBULENCE MODIFICATION two time scale DISSIPATION model wake effect
下载PDF
Exergy Analysis of Single Array Wind Farm Using Wake Effects 被引量:1
5
作者 A. Jeya Saravanan C. P. Karthikeyan Anand A. Samuel 《Engineering(科研)》 2011年第9期949-958,共10页
The influence of wake parameters on the exergy analysis of single array wind farm is studied in this paper. Key parameters which influence wake effects in a wind farm are wind velocity, tip speed ratio, number of blad... The influence of wake parameters on the exergy analysis of single array wind farm is studied in this paper. Key parameters which influence wake effects in a wind farm are wind velocity, tip speed ratio, number of blades, rotor speed, rotor diameter and hub height. Three different models namely power, wake and exergy model were used in estimating the exergy efficiency of the single array wind farm. Even though it is ideal for wind farms to fix the wind turbines in rows and columns the conditions of the site may not always be condu- cive for it. Hence analysis has been done keeping the wind turbines at random in a row and the effect of positioning on the performance is analyzed. Energy and exergy efficiency calculations were made for different cases by varying the positions of wind turbines in the single array wind farm. Standard relations were used in estimating the energy deficit in the wind farm due to wake effects. The wake effects were found to have an aggregated influence on the energy production of the wind farm, which results from the changes in the key parameters mentioned above. Potential areas for reducing energy losses by proper location and selection of turbines based on rating are highlighted. The influence of individual parameters contributing to the wake ef-fect were analyzed and discussed in detail. 展开更多
关键词 wake effect ENERGY EFFICIENCY EXERGY EFFICIENCY WIND Farms and WIND Turbines
下载PDF
Power quality assessment in different wind power plant models considering wind turbine wake effects
6
作者 Mohsen Khatamiaghda Saeed Bahraminejad Roohollah Fadaeinedjad 《Clean Energy》 EI CSCD 2023年第4期843-858,共16页
The intense increase in the installed capacity of wind farms has required a computationally efficient dynamic equivalent model of wind farms.Various types of wind-farm modelling aim to identify the accuracy and simula... The intense increase in the installed capacity of wind farms has required a computationally efficient dynamic equivalent model of wind farms.Various types of wind-farm modelling aim to identify the accuracy and simulation time in the presence of the power system.In this study,dynamic simulation of equivalent models of a sample wind farm,including single-turbine representation,multiple-turbine representation,quasi-multiple-turbine representation and full-turbine representation models,are performed using a doubly-fed induction generator wind turbine model developed in DIgSILENT software.The developed doubly-fed induction generator model in DIgSILENT is intended to simulate inflow wind turbulence for more accurate performance.The wake effects between wind turbines for the fullturbine representation and multiple-turbine representation models have been considered using the Jensen method.The developed model improves the extraction power of the turbine according to the layout of the wind farm.The accuracy of the mentioned methods is evaluated by calculating the output parameters of the wind farm,including active and reactive powers,voltage and instantaneous flicker intensity.The study was carried out on a sample wind farm,which included 39 wind turbines.The simulation results confirm that the computational loads of the single-turbine representation(STR),the multiple-turbine representation and the quasi-multiple-turbine representation are 1/39,1/8 and 1/8 times the full-turbine representation model,respectively.On the other hand,the error of active power(voltage)with respect to the full-turbine representation model is 74.59%(1.31%),43.29%(0.31%)and 7.19%(0.11%)for the STR,the multiple-turbine representation and the quasi-multiple representation,respectively. 展开更多
关键词 wind-farm models DIgSILENT software flicker intensity wake effect DFIG turbine
原文传递
Smart load control of the large-scale offshore wind turbine blades subject to wake effect 被引量:1
7
作者 Mingming Zhang Bin Tan Jianzhong Xu 《Science Bulletin》 SCIE EI CAS CSCD 2015年第19期1680-1687,共8页
The smart fatigue load control of a large-scale wind turbine blade subject to wake effect was numerically investigated in this paper. The performances were evaluated and compared at selected typical wind speeds within... The smart fatigue load control of a large-scale wind turbine blade subject to wake effect was numerically investigated in this paper. The performances were evaluated and compared at selected typical wind speeds within the whole operational region under three turbine layout strategies, i.e., column, row and array arrangements, together with a single turbine case as reference, utilizing our newly developed aero-servo-elastic platform. It was observed that not only the blade fatigue loads but the stabilities of power and collective pitch angle were effectively controlled for all cases, especially at the highest studied hub velocity of20 m/s, leading to the averaged reduction percentages in the standard deviations of the flapwise root moment, the flapwise tip deflection and the root damage equivalent load, of about 30.0 %, 20.0 % and 20.0 %, respectively. Furthermore, the control effectiveness gradually lessened in the sequences of single, column, row and array cases, with successively increasing effective turbulence intensity,within regions II and III. The performances in region III,associated with the impaired flow separation on the blade by the effective pitching action, were much better than those in region II, related to enhanced flow detachment. In addition,at the rated wind velocity, the control for the array case was superior over other three cases, which was thought to be originated from the more pitch activities to impair the uncontrolled flow separation on the blade surface. 展开更多
关键词 Smart rotor control Offshore wind energy Fatigue load wake effect Turbine layout strategy
原文传递
Study on the Wake Shape behind a Wing in Ground Effect Using an Unsteady Discrete Vortex Panel Method
8
作者 Cheolheui Han Spyros A. Kinnas 《Open Journal of Fluid Dynamics》 2013年第4期261-265,共5页
The unsteady evolution of trailing vortex sheets behind a wing in ground effect is simulated using an unsteady discrete vortex panel method. The ground effect is included by image method. The present method is validat... The unsteady evolution of trailing vortex sheets behind a wing in ground effect is simulated using an unsteady discrete vortex panel method. The ground effect is included by image method. The present method is validated by comparing the simulated wake roll-up shapes to published numerical results. When a wing is flying in a very close proximity to the ground, the optimal wing loading is parabolic rather than elliptic. Thus, a theoretical model of wing load distributions is suggested, and unsteady vortex evolutions behind lifting lines with both elliptic and parabolic load distributions are simulated for several ground heights. For a lifting line with elliptic and parabolic loading, the ground has the effect of moving the wingtip vortices laterally outward and suppressing the development of the vortex. When the wing is in a very close proximity to the ground, the types of wing load distributions does not affect much on the overall wake shapes, but parabolic load distributions make the wingtip vortices move more laterally outward than the elliptic load distributions. 展开更多
关键词 wake SHAPE WING in Ground effect UNSTEADY DISCRETE VORTEX Method
下载PDF
火箭弹尾流冲击效应研究
9
作者 曲普 姜瑞洲 孙耀东 《火炮发射与控制学报》 北大核心 2024年第5期9-15,共7页
以火箭弹尾流场及发射平台为研究对象,基于计算流体动力学方法,采用有限体积法进行数值离散,建立火箭弹尾焰燃气流场数学物理模型进行计算。分析火箭弹尾焰射流与发射平台的相互作用,探究燃气流场速度、温度和压力等参数分布特性,并研... 以火箭弹尾流场及发射平台为研究对象,基于计算流体动力学方法,采用有限体积法进行数值离散,建立火箭弹尾焰燃气流场数学物理模型进行计算。分析火箭弹尾焰射流与发射平台的相互作用,探究燃气流场速度、温度和压力等参数分布特性,并研究发射过程中尾焰燃气流对发射平台的冲击效应,得到发射平台关注区域表面压力、温度变化规律。之后对不同材料表面进行数值模拟及实验模拟对比,研究结果表明由钢材料替换铝材料后,钢材料表面温度低于熔点,可减小温度对平台的影响,为火箭弹发射平台防护及优化提供了理论依据。 展开更多
关键词 火箭弹 尾流场 冲击效应 防护优化 数值模拟
下载PDF
计及尾流的风电场智能等效建模及偏航优化控制
10
作者 蔡玮 胡阳 刘吉臻 《动力工程学报》 CAS CSCD 北大核心 2024年第7期1051-1059,共9页
大型风电场中存在的尾流干扰会降低风电场整体输出功率,因此需要对风电场建立等效模型,并通过优化尾流分布来提升风电场整体功率输出能力。在所提出的新型风电场偏航优化框架中,提出了一种利用参数监督学习和正则化技术改进的径向基函... 大型风电场中存在的尾流干扰会降低风电场整体输出功率,因此需要对风电场建立等效模型,并通过优化尾流分布来提升风电场整体功率输出能力。在所提出的新型风电场偏航优化框架中,提出了一种利用参数监督学习和正则化技术改进的径向基函数神经网络算法,并建立了面向多自由度偏航控制的风电场功率转换智能等效模型。在该模型的基础上,定义了以风电机组偏航角为决策变量的场级最大输出功率优化问题,提出了一种改进的精英多种群遗传算法并进行优化求解,得到各机组偏航角优化值以减少机组间尾流干扰。利用实际风电场布局和风况数据进行了仿真测试。结果表明:所建立的风电场功率转换智能等效模型与其实际特性吻合良好,在特定风况下,偏航优化控制使得风电场总功率提升718.79 kW;连续风况下,所提优化控制方法在不同风况下均有明显的优化效果,风电场总功率平均提升1208 kW,验证了所提出的新型风电场偏航优化框架在提升风电场整体输出功率上的优越性。 展开更多
关键词 风电场 尾流效应 径向基函数 神经网络 偏航角优化 多种群遗传算法
下载PDF
灌门水道水轮机阵列布置对潮流运动特性的影响
11
作者 王树潼 武贺 陈娅玲 《船舶工程》 CSCD 北大核心 2024年第6期123-131,共9页
潮流能水轮机机组的运行会改变潮流运动结构,引起局部区域的水动力特性发生变化,进而影响机组的获能效率。对此,以舟山群岛灌门水道为例,基于Delft 3D软件建立三维水动力学模型,研究机组阵列交错布置对运动潮流的影响。通过网格嵌套分... 潮流能水轮机机组的运行会改变潮流运动结构,引起局部区域的水动力特性发生变化,进而影响机组的获能效率。对此,以舟山群岛灌门水道为例,基于Delft 3D软件建立三维水动力学模型,研究机组阵列交错布置对运动潮流的影响。通过网格嵌套分别模拟舟山群岛和灌门水道的潮流运动特征,采用多孔盘法模拟水轮机阵列对潮流空间结构的作用。研究表明:多排机组阵列运行之后,水轮机及下游潮流流速会显著下降,并引起垂向上转轮上、下边缘区流速增加;水轮机迎流方向水位上升,涨、落急时刻最大壅水差值达10cm;水轮机底部及机组之间的床面切应力增大,尾流影响区切应力减小;尾流叠加,床面切应力进一步减小,落急时刻尾流区的床面切应力减小量可达54.03%,阵列两侧床面切应力增大量可达177.93%。在未来的潮流能开发选址中,应全面评估布置水轮机后可能引起的潮流运动特性变化,优化阵列布置,降低对环境的影响。 展开更多
关键词 灌门水道 水轮机阵列 尾流效应 阻塞作用 床面切应力
下载PDF
风电机组双高斯分布致动盘模型研究
12
作者 吴雨露 王坤宁 +1 位作者 孟航 李莉 《风机技术》 2024年第3期80-85,共6页
准确高效的风电机组尾流模拟对风电场开发设计和优化运行至关重要,CFD方法与简化风轮的致动盘模型相结合是目前工程中常用的尾流数值模拟方法。针对传统的非均匀分布致动盘模型在近尾流区模拟精度不足的问题,提出双高斯分布致动盘模型... 准确高效的风电机组尾流模拟对风电场开发设计和优化运行至关重要,CFD方法与简化风轮的致动盘模型相结合是目前工程中常用的尾流数值模拟方法。针对传统的非均匀分布致动盘模型在近尾流区模拟精度不足的问题,提出双高斯分布致动盘模型。该模型考虑了叶片受力特性和尾流分布特征,使体积力在致动盘面上沿径向呈双高斯曲线分布。以风洞实验和风电场实测数据为例进行流场数值模拟。结果表明:双高斯分布致动盘模型适用于推力系数较高的大型风电机组,整体尾流速度模拟精度较高,可准确模拟出尾流半径沿流向的变化,在近尾流区显著改善了传统非均匀致动盘模型低估速度损失的问题。 展开更多
关键词 尾流效应 致动盘模型 双高斯分布
下载PDF
The assessment of extactable tidal energy and the effect of tidal energy turbine deployment on the hydrodynamics in Zhoushan 被引量:5
13
作者 HOU Fang BAO Xianwen +1 位作者 LI Benxia LIU Qianqian 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2015年第5期86-91,共6页
In this study, we construct one 2-dimensional tidal simulation, using an unstructured Finite Volume Coastal Ocean Model (FVCOM). In the 2-D model, we simulated the tidal turbines through adding additional bottom dra... In this study, we construct one 2-dimensional tidal simulation, using an unstructured Finite Volume Coastal Ocean Model (FVCOM). In the 2-D model, we simulated the tidal turbines through adding additional bottom drag in the element where the tidal turbines reside. The additional bottom drag was calculated from the relationship of the bottom friction dissipation and the rated rotor efficiency of the tidal energy turbine. This study analyzed the effect of the tidal energy turbine to the hydrodynamic environment, and calculated the amount of the extractable tidal energy resource at the Guishan Hangmen Channel, considering the rotor wake effect. 展开更多
关键词 extractable tidal energy resource rotor wake effect tidal energy turbine
下载PDF
基于三维卷吸尾流模型的风电场功率计算
14
作者 凌子焱 赵振宙 +3 位作者 刘一格 刘惠文 马远卓 王丁丁 《中国电机工程学报》 EI CSCD 北大核心 2024年第21期8488-8495,I0013,共9页
风电场中风力机尾流产生叠加效应。为更加准确地计算风电场的尾流风速的分布,该文基于作者前期建立的单台风力机的三维余弦形状的卷吸尾流模型(3DCLE模型),考虑尾流叠加效应,建立了风电场尾流模型(3DCLEWFM)。通过Horns Rev海上风电场及... 风电场中风力机尾流产生叠加效应。为更加准确地计算风电场的尾流风速的分布,该文基于作者前期建立的单台风力机的三维余弦形状的卷吸尾流模型(3DCLE模型),考虑尾流叠加效应,建立了风电场尾流模型(3DCLEWFM)。通过Horns Rev海上风电场及Nørrekær Enge陆上风电场的实测数据来进行验证。结果表明,3DCLEWFM能够精准预测不同风向下风电场中风力机的输出功率,两种案例下,精度较Jensen风电场尾流模型(Jensen wind farm model,JWFM)提高65%和86%,较BPA风电场尾流模型(BPAWFM)提高48%和66%。 展开更多
关键词 风力机 三维尾流模型 尾流叠加效应 风电场
下载PDF
考虑大气稳定度的风电场等效粗糙度模型研究
15
作者 李宝良 张子良 +2 位作者 葛铭纬 王罗 刘永前 《太阳能学报》 EI CAS CSCD 北大核心 2024年第1期258-264,共7页
目前模型未充分考虑大气稳定度的影响,针对该问题,在不同大气稳定度下,通过建立风电场边界层的动量平衡关系和揭示风电场的流动不均匀性,提出一种适用于不同大气稳定度的风电场等效粗糙度模型。采用大涡模拟方法对所提模型进行验证,结... 目前模型未充分考虑大气稳定度的影响,针对该问题,在不同大气稳定度下,通过建立风电场边界层的动量平衡关系和揭示风电场的流动不均匀性,提出一种适用于不同大气稳定度的风电场等效粗糙度模型。采用大涡模拟方法对所提模型进行验证,结果显示该方法能有效评估大气稳定度对风电场流动不均匀性以及等效粗糙度的影响,所得等效粗糙度平均误差约10%。 展开更多
关键词 风电场 大气边界层 尾流 大涡数值模拟 等效粗糙度模型
下载PDF
考虑尾流效应的风电场分群综合惯性控制研究
16
作者 何银 何宇 温拥军 《机械与电子》 2024年第3期32-39,共8页
为解决尾流效应导致风电场风速分布不均匀、风电场单机等值模型不能进行精准综合惯性控制的问题,提出一种风电场分群综合惯性控制策略。该策略以具备相近调频能力为机组分群原则,定义调频能力因子作为分群指标,通过聚类算法对机组进行... 为解决尾流效应导致风电场风速分布不均匀、风电场单机等值模型不能进行精准综合惯性控制的问题,提出一种风电场分群综合惯性控制策略。该策略以具备相近调频能力为机组分群原则,定义调频能力因子作为分群指标,通过聚类算法对机组进行动态分群;综合惯性控制环建立以系统频率偏差量、系统频率变化率为输入,惯性控制比例系数、惯性控制微分系数为输出的模糊自适应综合惯性控制器,进而实现风电场分群综合惯性控制。仿真结果表明,所提出的分群指标是有效的,建立的风电场多机等值模型较准确地体现了各机组群的调频能力,且建立的风电场分群综合惯性控制策略可以提供更为可靠的惯性支撑。 展开更多
关键词 风电场 尾流效应 动态等值 多机表征 综合惯性控制
下载PDF
多感觉刺激辅助常规促醒对颅脑损伤昏迷患者的促醒效果及神经功能的影响
17
作者 吕玲 辜丽影 吴津津 《中国医药指南》 2024年第28期174-176,共3页
目的探讨多感觉刺激辅助常规促醒用于颅脑损伤昏迷患者的促醒效果及对神经功能的影响。方法按照随机数字表法将2019年3月至2022年12月中国人民解放军联勤保障部队第九一〇医院收治的84例颅脑损伤昏迷患者分为观察组和对照组,每组42例。... 目的探讨多感觉刺激辅助常规促醒用于颅脑损伤昏迷患者的促醒效果及对神经功能的影响。方法按照随机数字表法将2019年3月至2022年12月中国人民解放军联勤保障部队第九一〇医院收治的84例颅脑损伤昏迷患者分为观察组和对照组,每组42例。对照组行常规促醒,观察组在对照组基础上行多感觉刺激。对比两组患者清醒情况、格拉斯哥昏迷量表(GCS)评分、昏迷恢复量表(CRS-R)评分及美国国立卫生研究院卒中量表(NIHSS)评分。结果干预15 d时,观察组清醒比例高于对照组(54.76%vs.28.57%,P<0.05);干预30 d时,观察组清醒比例高于对照组(90.48%vs.52.38%,P<0.05);观察组清醒时间短于对照组(P<0.05)。干预后,两组患者GCS评分和CRS-R评分均提高,且观察组上述评分均高于对照组(P<0.05);干预后,两组患者NIHSS评分均降低,且观察组低于对照组(P<0.05)。结论多感觉刺激辅助常规促醒相比单纯常规促醒能够更有效提高颅脑损伤昏迷患者的促醒效果,缩短昏迷时间,改善神经功能。 展开更多
关键词 颅脑损伤 多感觉刺激 常规促醒 促醒效果 神经功能
下载PDF
计及尾流效应的风电场短路故障动态等值建模
18
作者 余浩 黎灿兵 +5 位作者 叶志亮 彭穗 任万鑫 陈思捷 唐彬伟 陈达伟 《上海交通大学学报》 EI CAS CSCD 北大核心 2024年第6期798-805,共8页
快速、准确分析大型风电场短路特性具有重要的工程应用价值,而尾流效应影响下风电场各机组短路特性差异大,需建立风电场短路故障时等值模型.提出一种考虑尾流效应影响的风电场短路故障动态等值方法,首先定义尾流效应因子反映机组受尾流... 快速、准确分析大型风电场短路特性具有重要的工程应用价值,而尾流效应影响下风电场各机组短路特性差异大,需建立风电场短路故障时等值模型.提出一种考虑尾流效应影响的风电场短路故障动态等值方法,首先定义尾流效应因子反映机组受尾流效应影响程度,并采用尾流效应因子作为分组依据,缩小尾流效应影响下组内各机组运行状态差异性.为提高非对称短路故障下的等值模型有效性,分析风电场短路时正、负、零三序网络的构成,提出适用于零序集电网络的等值方法,搭建平台并加以验证.仿真结果表明,该风电场短路故障动态等值模型能准确反映尾流效应影响下风电场有功、无功短路输出特性. 展开更多
关键词 尾流效应 风电场 短路故障 聚类算法 动态等值模型
下载PDF
大基地风电场“以大代小”等容量排布方案分析
19
作者 王成 《中外能源》 CAS 2024年第4期34-39,共6页
“以大代小”是风电项目进行等容或扩容改造升级常用的一种方式。以大基地风电场为研究对象,探究针对大基地项目进行“以大代小”技术改造的规划方案。将大基地风电场划分为9个待改造区域,分别采用两种改造方案,从机组单机容量、机组轮... “以大代小”是风电项目进行等容或扩容改造升级常用的一种方式。以大基地风电场为研究对象,探究针对大基地项目进行“以大代小”技术改造的规划方案。将大基地风电场划分为9个待改造区域,分别采用两种改造方案,从机组单机容量、机组轮毂高度、改造区域机组对周边机组的尾流影响等几个关键因素入手,分析这些因素对场区发电量的影响及发电量提升效果,进而得到最优的改造机型和布局规划。研究结果表明,保持轮毂高度不变,提升单机容量,发电量增加幅度并不显著。当抬升轮毂高度且提升机组单机容量时,发电量提升效果较为明显。当选取的轮毂高度与周边机组轮毂高度较为接近时,随着改造区域单机容量增大,对周边机组的尾流影响越大,影响最大的为处于改造区域下风向的机组,影响最小的通常为处于改造区域上风向的机组。抬升轮毂高度,随着单机容量的提升,发电量提升效果较为显著。根据大基地风电场的实际风资源条件,在场区中间区域适当抬升轮毂高度,可以提升发电量并减少对周边风电场的尾流影响。等容量技术改造时,应优先选择高塔架大兆瓦机组进行改造。 展开更多
关键词 大基地风电场 等容量排布 单机容量 轮毂高度 尾流影响 发电量
下载PDF
固体火箭尾流场对舱体冲击效应研究
20
作者 刘毅 曲普 +1 位作者 李强 姜瑞洲 《弹箭与制导学报》 北大核心 2024年第2期90-96,共7页
火箭燃气射流对搭载平台的冲击效应是搭载平台表面防护和结构设计的重要依据。为研究不同射角下高速射流对舱体的冲击效果,基于有限体积法,采用SST k-ω湍流模型,建立固体火箭发射过程的三维仿真物理模型。分别在70°射角和56°... 火箭燃气射流对搭载平台的冲击效应是搭载平台表面防护和结构设计的重要依据。为研究不同射角下高速射流对舱体的冲击效果,基于有限体积法,采用SST k-ω湍流模型,建立固体火箭发射过程的三维仿真物理模型。分别在70°射角和56°射角工况下,对固体火箭发动机喷出的燃气射流进行数值模拟,得到了不同时刻射流的特性以及两射角下舱体上表面受射流影响情况,分析射流对舱体表面的冲击效应。分析结果表明,射流冲出喷管后在空气中膨胀,形成曲面激波。抵达舱体表面后压缩,产生高温高压区,随后温度和压力沿舱体表面流动逐渐降低。舱体表面温度和压力变化趋势相一致,56°射角时舱体表面温度较低,受到的冲击效应更大。 展开更多
关键词 尾流场 燃气射流 数值模拟 冲击效应
下载PDF
上一页 1 2 19 下一页 到第
使用帮助 返回顶部