摘要
流体经过一定的逆压梯度容易发生流动分离从而大大减小流动效率,球窝结构具有良好的流动控制效果,在机翼、航空发动机、汽轮机叶片等工业领域有较大的应用前景。对一典型收缩扩张通道的流动分离转捩状况进行了数值模拟,并提出了一种带有球窝结构的被动控制方法。研究结果表明:球窝结构作为一种被动流动控制方法,布置在具有明显逆压梯度的通道上能起到良好的流动控制作用,并且能诱导层流边界层提前向湍流边界层转捩,抑制了通道中的流动分离,减小分离泡的尺度,其中球窝的布置位置以及流动Re均对球窝的控制作用有重要影响。球窝的引入还将减小通道的总压损失系数,起到了流动减阻的效果,表明球窝结构是一种较优的流动控制方法。
Fluids are easy separated under adverse pressure gradient which results in low flow efficiency. Dimple structures are optimal flow control approach which has broad application prospects on industrial areas such as airfoils, aero engines and turbine blades. The three-dimensional Reynolds- averaged Navier-Stokes （RAINS） equations were resolved using shear- stress-transport （SST） turbulence model and T-Re0 transition model. Flow separation and boundary layer transition characteristics of a typical convergent-divergent channel were investigated by the numerical method. Dimple structure was adopted to control the flow process passively. After comparing with the none-control channel, results indicate that. As a passive flow control method, dimple structure can control the flow process on a channel with obvious adverse pressure gradient. It induces the boundary layer transition from laminar to turbulent. Dimple restrains the flow separation while decreasing separation bubble scale. The parameters of dimple position and Reynolds number affect the flow control process considerably. The import of dimple structure also decreases the total pressure loss ratio coefficient which implies a flow resistance reduction effect. Dimple structure is implied as a relatively optimal flow control method.
出处
《热科学与技术》
CAS
CSCD
北大核心
2012年第4期352-357,共6页
Journal of Thermal Science and Technology
关键词
低压透平
球窝
分离
转捩
流动控制
low-pressure turbine
dimple separation
transition flow control
