查询词典 vortex flow

The numerical results are analyzed based on the field synergy principle to explain the inherent mechanism of heat transfer enhancement by longitudinal vortex, namely second flow generated by the vortex generators causes the reduction of the intersection angle between the velocity and fluid temperature gradient.

结果发现纵向涡强化管－翅表面换热的内在机理可以用场协同原理进行解释，即纵向涡发生器使全场速度和温度梯度之间的平均夹角减小。

The purpose of flow visualization research of sections in double delta wing is to uncover the mechanism of vortex interference and structure,from this research,we can control the vortex and provide lasis for constructing numerical model.

进行双三角翼翼面流动显示研究的目的是为了揭示前、后翼脱体涡的干扰机理和详细结构，进而达到控制表面涡分离的目的，并为计算流体力学建立数学模型提供依据。

The paper introduces some researches, such as a new method to calculate the added mass for the seismic analysis of the fuel assembly in fast breeder reactor, simulation on the vortex shedding of double heat exchange tubes in a steam generator, simulation on the vortex shedding caused by the cross -flow over plates in a fuel assembly of an advanced reactor, the research on the impacting phenomenon of the free-surface on the vessel head in a storage tank as the main vessel of the China Experimental Fast Reactor shaken by the earthquake, and the researches on the solution of the liquid sloshing by moving particle semi-implicit and the scattering phenomenon caused by sloshing, and so on.

本文介绍华北电力大学在该方面的一些研究进展，例如，快堆燃料组件抗震分析新的流体附加质量计算方法研究；蒸汽发生器换热管双管漩涡脱落的数值模拟；一个先进堆燃料组件平行板上流动引起的漩涡脱落数值模拟；由地震引起的自由表面对快堆主容器冲击现象的研究；移动粒子法求解液面晃动及晃动引起离散现象的研究等。

Based on the analysis of multiphase flow in vortex field,including the analysis of forces exerted on and the movement of droplets,the mechanism of vortex field coalescence was investigated.

在对旋流场内多相流的分析，包括分散液滴的受力和运动分析的基础上，研究了旋流聚结的机理，并通过试验验证了旋流场内聚结过程的存在，且发现在某一进料流量时聚结效果特别明显，即存在最佳进料流量或入口雷诺数。

Comparing the unsteady flow fields obtained by CFD with the measurement results with SPIV, it can be found that the CFD results can capture the main characteristics of the flow fields observed in the experiment results, however, the precision of the CFD needs to be further improved, and to predict the detail flow structures, such as the tip leakage vortex in the compressor rotor, by CFD still has some difficulties, thus, some work should be done to improve the turbulence model for more accuracy prediction of the flow fields by CFD for the complex flow in turbomachinery.

定常计算结果和非定常计算结果都不能很好地反映出转子叶尖泄漏流，转子尾迹和泄漏流在静子通道中的演化，及其与静子的相互作用等复杂流动情况。开展叶轮机适用的湍流模型研究，对于提高叶轮机内部复杂流动数值模拟的准确性具有非常重要的价值。

In the context of a system of barotropic shallow-water equations and Boussinesq approximate equations for two-dimensional meso-scale transversal wave disturbance in zonally sheared base flow, study is performed of the physical process of the meso disturbance propagation along the flow, indicating that such vortex Rossby waves are separated into two kinds. The first kind VRW is produced owing to the second-order horizontal shear in the flow or due to the meridional change in vertical vorticity of the flow, i.

本文使用正压浅水方程组以及纬向切变基流下二维中尺度横波型扰动的Boussinesq近似方程组，分析了这种沿着基本气流方向传播的中尺度扰动的波动传播物理过程。

Evidence suggests that 1 under more stable stratification, the basic flow, if moving faster at low and high levels (particularly in the presence of jets there), allows a resulting meso-β unsteady wave to propagate eastward with respect to basic flow and even at greater velocity compared with it; 2 vertical windspeed shear of basic flow causes instabilities of the TWT perturbation; 3 considering the second derivative of basic-flow wind with respect to z (denoted by zz≠ 0 which is simply given as β* hereafter) the expression for the phase velocity of vortex Rossby wave is obtained, which is unidirectional in propagation with respect to basic flow; 4 VRoW has its physical origin from β*, i.e., from z-varying heterogeneities of y-direction averaged vorticity of the basic flow field; 5 VRoW phase velocity is associated with zonal wave number k, its energy is dispersive and the group velocity exists in the x direction; 6 when windspeed meets the condition of β*, TWT disturbance instability may be that of mixed VRoW and gravity wave; 7 if basic flow is subject to linear shear but does not meet the condition of β*, the TWT instability is that of inertia-gravity wave.

在大气层结比较稳定的情况下，如果基本气流在低层和高层较大(有可能存在低空急流和高空急流)，此时产生的β中尺度不稳定扰动相对于基流向东传播，甚至于快速向东传播。基本气流在垂直方向上的风速切变对于中尺度横波型的扰动起着不稳定的作用。如果考虑基流的二次切变，可以得到涡旋Rossby波的相速度表达式，涡旋Rossby波相对于基本气流是单向传播的。涡旋Rossby波产生的物理根源是基本流场的风速二次切变，亦即基本流场y方向的平均涡度在空间z方向上的不均匀所致。涡旋Rossby波的相速度与纬向波数也有关，它的能量是频散的，其在纬向x方向也存在群速度。在基本流场的风速存在二次切变时，横波型不稳定可能是混合的涡旋Rossby重力波的不稳定；而在基本流场的风速仅仅存在线性切变，不存在二次切变时，横波型扰动的不稳定则是重力惯性波的不稳定。

The swirling flow inside the cyclone showed the Rankine vortex characteristics, i e, strong swirling vortex at the central region of the cross-section and weak swirling quasi-free vortex near the wall.

方形旋风分离器内的流动具有Rankine涡的特点，即中心部分为强制涡区，边壁附近是准自由涡区。

The hydrodynamic performance and the calculation of induced velocity along flow on the constant point after foil shows that if the effects of tip vortex and decay of vortex panel strength be considered, the accuracy of calculation can be increased. Velocity peak value in propeller wake current and distribution of induced velocity after three-dimensional short foil else can be calculated accurately.

通过对三维短翼的水动力性能和翼后给定点沿流向的诱导速度计算表明：采用考虑翼梢涡影响和涡的衰减影响的计算模型，可以提高三维短翼的水动力性能计算精度；可以准确地计算出螺旋桨尾流场的速度峰值；可以较好地计算出三维短翼翼后的诱导速度分布。

Corresponding to simulation results, middle flow shows more regular because vortex separation from upstream tube bundles suppress the vortex generation in downstream.

由于多个拟序的涡结构在下游不断的相互作用使得尾迹中的涡结构越来越混乱。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。