论文部分内容阅读
零质量射流是一种主动流动控制技术,具有结构紧凑,无需外界气源等优势。为了把零质量射流用于控制风电叶片表面流动,需要理解和掌握零质量射流的一些基本特征。本文采用求解雷诺平均NS方程的方法,以静止环境中的二维零质量射流为研究对象,研究4种激励速度和4种激励频率时零质量射流对流场扰动的基本特征,并对流场结构进行了拓扑分析。结果表明,零质量射流会在孔口处产生旋涡对,旋涡对在自身的诱导作用下不断向外扩展;由于射流速度的周期性变化,在孔口下游轴线产生鞍点,激励速度越大,鞍点运动速度越快,距孔口距离越远;激励频率越大,旋涡最大涡量值越大,涡核中心距孔口距离越近,涡核间距越小。
Zero-mass jet is a kind of active flow control technology, with the advantages of compact structure, no external air source and so on. In order to use zero mass jet flow to control the surface of wind turbine blades, some basic characteristics of zero mass jet need to be understood and mastered. In this paper, by solving the Reynolds-averaged Navier-Stokes equations, the two-dimensional zero-mass jet in static environment is taken as the research object. The basic characteristics of zero-mass jet perturbation of the jet flow field are studied when the four excitation velocities and the four excitation frequencies are used. Structure of the topology analysis. The results show that the zero-mass jet will generate vortex pairs at the orifice, and the vortex pairs continue to expand outward under its own induction. Due to the periodic change of jet velocity, the saddle point is generated on the downstream axis of the orifice, the greater the excitation speed, The faster the velocity is, the farther it is from the orifice. The larger the excitation frequency is, the larger the vorticity value of the vortex is. The closer the center of vortex nucleus is to the orifice, the smaller the vortex core spacing.