涡

Tidal mixing plays a key role in the simulation of the thermal structure of the ocean, and how to calculate the value of the vertical kinematic viscosity coefficient in ocean models is very important.

海流数值模拟从二维过渡到三维，垂直涡动粘性系数的确定成为一个研究热点，潮混合在海洋热结构的数值模拟上起着非常重要的作用。

The Phoenix reproduces that pair of small fascinating whirlpools on her face, and smiles simply: Dear Prof.

凤凰脸上再现那对醉人的小酒涡，浅笑道：亲爱的桥杰教授，今晚你是属于大家的，不属于个人。

The Phoenix reproduces that pair of small fascinating whirlpools on her face, and smiles simply: Dear Prof. Chau Jie, you will belong to everybody this evening, and not belong to a person.

凤凰脸上再现那对醉人的小酒涡，浅笑道：亲爱的桥杰教授，今晚你是属于大家的，不属于个人。

According to rubbing mechanism lead to by various causes, the diagnosis rules about the features of vibration time waveshape, amplitude surge and amplitude increasing speed, two-dimension hologram Specturm purified, oil film pressure and journal whirling motion are put forward.

根据各种原因引起碰摩的机理，相应地提出了振动时波特征、振幅波动及增加速率特征、提纯二维全息谱特征、油膜压力特征和轴颈涡动特征等诊断规则。

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 above problems are studied in this thesis. First, the implicit NND scheme with mix flux splitting method proposed by Zhang Hanxin that is first order accurate in time and second order in space is modified. The modified scheme keeps the characteristics of fast convergence and is second order accurate both in time and space. It can be capable of simulating the unsteacly flow. Second, the topological method founded by Zhang Hanxin is improved to study the characteristics of vortex near the singular point on its axis and the cross streamlines on the longitudinal section passing the vortex axis. On the basis of topological results, a program which visualises numerical results is made out. It can help us analyse the characteristics of vortex motion.

本文对上述问题做了研究：第一，在数值模拟方面，借助于张涵信提出的NND算法和混合通量法，我们将他建立的时间为一阶、空间为二阶精度的快速隐式算法推广为时间和空间均为二阶精度的算法，这样做保留了原格式收敛快的特点，而且能适用于真实的非定常流态的计算；第二，将张涵信的拓扑分析方法加以推广，研究了涡轴附近及破裂点邻域内流场的空间特征，并以这些拓扑分析结果为指导，研制了一套显示计算结果的软件，这一软件能很好地帮助我们分析流场的计算结果和旋涡演变的特征。

According to the results of analysis, the shape of the spiral case and stay vanes were improved to reduce the hydraulic losses.

根据解析结果，对涡壳和固定导叶进行了改进以减少水力损失。

It has two Turbomeca Astazou XVIG turboprops, max power 978 equivalent shaft hp each.

透博梅卡·阿斯塔左XVIG涡桨发动机的单台推力为978轴马力。

Overall, Ascend counts more than 2,300 aircraft in storage, including turboprops, transports used for VIP/head of state or business aviation purposes and non-Western-built aircraft, and Chris Seymour, the firm's head of market analysis, says the number is growing steadily.

航升估计有超过2300架飞机处于封存状态，其中包括涡浆飞机，国家和商业首脑的专机，非西方产的飞机。

Subsequent prototypes turned to use the French Turbomeca Astazou XVIG turboprops.

后继的原型机转为使用法国透博梅卡·阿斯塔左XVIG涡桨发动机。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。