摘要
引入双时间方法,计算了某三维平板振荡叶栅的非定常流场.在虚拟时间步上用LU-SGS隐式方法做时间推进,对流项采用空间三阶的加权无波动无自由参数耗散差分(WNND)格式离散.湍流模型采用低雷诺数q-ω模型.计算得到了叶栅不同叶高处的升力系数频谱、非定常压差系数以及叶尖处不同振动时刻的熵等值线.对3个叶高处的升力系数频谱分析表明,流场存在显著的振动诱发的非线性扰动,其频率高于升力系数基频.叶尖处不同振动时刻的熵等值线图显示了大振幅下流场强烈的非定常属性.
A dual-time method was introduced to calculate the unsteady flow in a certain oscillating flat cascade. An implicit LU-SGS scheme was applied for time stepping in pseudo time domains, and the convection items were discretized with the spatial three-order and weighted non-oscillatory and non-freeparameter dissipation difference （WNND） scheme. The turbulence model adopts q- ω low-Reynolds-number model. The frequency spectrums of lift coefficients and the unsteady pressure difference coefficients at different spanwise heights as well as the entropy contours at blade tips on different oscillating instants were obtained. By the analysis of frequency spectrums of lift coefficients at three spanwise heights, it is considered that there exist obvious non-linear perturbations in the flow induced by the oscillation, and the perturbation frequencies are higher than the basic frequency. The entropy contours of blade tips at different times display an intensively unsteady attribute of the flow under large amplitudes.
出处
《上海交通大学学报》
EI
CAS
CSCD
北大核心
2006年第12期2147-2150,2154,共5页
Journal of Shanghai Jiaotong University
关键词
振荡叶栅
加权无波动无自由参数耗散差分格式
升力系数频谱
非定常压差系数
oscillating cascade
weighted non-oscillatory and non-free-parameter dissipation difference （WNND） scheme
frequency spectrum of lift coefficient
unsteady pressure difference coefficient
