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通过直接数值模拟研究竖直平板间温差湍流自然对流的相干结构．研究表明，流场中同时存在大尺度展向涡结构和螺旋羽流结构．螺旋羽流结构对应于流场中相对螺度、法向涡量及脉动温度较大的位置．定性分析了螺旋羽流结构的形状、特点、成因以及与Ｒａｙｌｅｉｇｈ－Ｂｅｎａｒｄ对流的异同，并应用条件采样分析说明了螺旋状热羽流结构的主要特性．
The direct numerical simulation is used to study the coherent structure of turbulent natural convection between vertical plates. The results show that both the large-scale vortex structure and the spiral plume structure exist in the flow field. The spiral plume structure corresponds to the position of relative helix, normal vorticity and pulsation temperature in the flow field. The shape, characteristics, genesis and the similarities and differences of the Rayleigh-Benard convection were analyzed qualitatively, and the main characteristics of the spiral-shaped thermal plume structure were illustrated by applying the conditional sampling analysis.