提出了同时描述鼓泡塔宏观流动及气泡尾涡小尺度湍动的双尺度流体力学模型,其中大尺度剪切流通过经典k-ε模型描述,而小尺度尾涡湍动则由"尾涡温度"传输方程确定。通过在运动方程添加"尾涡压力"源项,构建大小双尺度流体运动的相互作用,解释鼓泡塔内含率非均匀分布的机制。模型将鼓泡塔内的能量耗散分解3种作用机制:大尺度剪切流引起湍动耗散;小尺度尾涡湍动耗散;尾涡与壁面作用的能量耗散,较好地解决了现有鼓泡塔模型能量不守恒问题。模型计算稳定性高,模拟结果与实验结果吻合良好。

A new two-scale hydrodynamic model was proposed to describe large-scale motion and small-scale bubble wake turbulence. The large-scale shear induced turbulence was resolved by classical k-εturbulence model, while the small-scale bubble wake turbulence was quantitively described by wake temperature transport equation. A wake pressure gradient source term was added to the motion equation to reflect the mutual influence between small scale turbulence and large scale fluid motion and to explain the mechanism of holdup non-uniform distribution in the bubble column. The model classified the energy dissipation into three kinds of mechanism:large-scale shear induced turbulence dissipation, small-scale wake turbulence dissipation, energy dissipation due to interaction between bubble wake and solid wall. The model well resolved the issue about energy balance. Simulation results agreed well with experiment data.

采用全自由方式建立风力机尾流场的涡尾迹模型,引入"虚拟周期"的概念,并发展一种自适应松弛因子方法,从而改善了自由尾迹迭代的稳定性,提高了迭代收敛速度。利用建立的自由涡尾迹模型,计算了风力机叶片的尾流场结构、气动性能及叶片载荷,并与实验结果进行了对比分析。结果表明,尖速比越大,自适应松弛因子方法对缩小模型计算时间越有效;全自由涡尾迹模型能准确给出风力机尾流场的结构,包括尾迹的扩张以及叶尖涡和叶根涡的产生、发展和耗散的过程,风轮扭矩与实验数据吻合;叶片载荷分布的计算结果在低风速下与实验值基本一致,但是在大风速下差别较大,说明需要一个准确的失速模型。

A fully free vortex wake model of flow field and aerodynamic performance for wind turbine is presented .The dummy period concept is used to improve the convergence speed and stability of wake it-erations with an introduction of the adaptive relaxation .The wake structure ,the aerodynamic perform-ance and loads of wind turbine are predicted by the present model and compared with the experiment re-sults .T he adaptive relaxation factor method can reduce the computational overhead especially at the high tip speed ratios .The fully free vortex wake model can accurately predict the flow field structure including wake expansion and the developing process from generation to dissipation of blade tip and root vortices . The rotor torque agrees well with the experiment data .As for blade load distribution ,the calculation compares well with experiment at low wind speeds but diverges at high wind speeds ,indicating that an appropriate stall model is required for accurate prediction at high speeds

Kappel桨在梢部剧烈弯折,这样的几何结构能够抑制梢涡的形成,起到梢部加载的作用。为了模拟桨叶弯折后对整个桨叶受力分布的影响,本文通过CFD计算分析几何尺寸相似的弯折三维翼和平直三维翼的剖面环量分布,并以此为基础就面元法分析Kappel桨时的尾涡进行修正。利用修正尾涡模型的面元法计算Kappel桨的敞水性能,与未修改尾涡面的面元法计算结果作比较,并就面元法计算Kappel桨的Morino库塔条件和等压库塔条件进行相关说明。

The tip of Kappel propeller curved to the suction side with large tip rake, then the loaded of the blade tip would be increased and the tip vortex would be restrained. In order to obtain the variation of the circulation, it analyzed the circulation distribution of two 3 -D foils through CFD. The foils chosen had a similar geometry with the propeller blade, but one foil had a curved tip like Kappel propeller and the other was straight. Based on the different circulation distribution between the two 3 -D foils, it presented a wake model which can obtain a good result in the calculation of the open water performance with surface panel method. Then the Morino′s Kutta condition and pressure Kutta condition had been discussed.

以三叶片水平轴风力机为研究对象,建立了尾迹扩张模型,研究了叶片尾迹流动结构。涡面模型叶片无量纲环量的计算结果与经典环量数据对比,结果吻合较好。计算了根尖涡模型风轮面诱导速度随尾迹扩张系数的变化关系,得出了尖速比对气动性能的影响:推力系数与环量及尖速比成正比;对于不同环量,功率系数存在最佳尖速比。分析了尾迹扩张模型对气动性能的影响:推力系数和功率系数与尾迹扩张系数成正比,尾迹收敛参数对其影响甚微。

Tip-Root and vortex sheet configuration of prescribed vortex wake model were used to predict the aeroperfor -mance based on lifting line theory.For three blade horizontal axis wind turbine , the wake structure was constructed by introducing a wake expansion model .Reproduced non-dimensional circulation along the blade of vortex sheet configura -tion agrees well with the classical Goldstein Function .The calculated results of Tip-Root configuration showed the regu-larity of rotor plane induced velocity changing as wake expansion ratio varied .It’s demonstrated that thrust coefficient was proportional to circulation and tip speed ratio , and optimal power coefficient comes with the best tip speed ratio for different circulation.Thrust coefficient and power coefficient was proportional to wake expansion rate , while wake con-vergence parameter had little impact .

针对紧密编队飞行过程中产生的尾涡流场对空中加油机产生扰动影响的问题，建立了受油机扰动运动模型。将风扰动主要分解为大气紊流和加油机尾涡，分别建立工程化的Dryden大气紊流模型和尾涡模型，将叠加的2个扰动加入到受油机的非线性刚体运动方程中，并对受油机扰动运动进行仿真分析。仿真结果表明：该叠加的方法能够简单有效地模拟反映复杂的气流扰动，为进一步研究空中加油控制系统提供参考。

Trailing vortex is come into being during the close formation flight, which will truly influence the aerial refueling. The receiver aircraft disturbance modeling is aimed for solving this problem. One account of the wind influence of both atmosphere disturbance and trailing vortex of tanker aircraft, the engineering Dryden atmospheric disturbance model and trailing vortex model were built. Then the two superposed turbulences were introduced into the nonlinear rigid body equations of motion to simulate the perturbation motion of receiver aircraft. The result shows that the superposition method can easily and effectively simulate the complicated wind disturbance. The study can provide reference for further research of the aerial refueling control system.