【摘要】 通过流体力学方程组的数值模拟，研究了侧向周期加热条件下普朗特数Pr=0.703的流体对流对格拉晓夫数Gr的依赖性。结果表明：随着格拉晓夫数Gr的增加，腔体中出现3种对流斑图阶段，即稳态对流、周期性对流和非周期性对流。从稳态对流向周期性对流过渡的临界格拉晓夫数Gr=1.448×10~4，从周期性对流向非周期性对流过渡的临界格拉晓夫数Gr=1.348×10~6。在稳态对流阶段，对流特性参数（水平流速和垂向流速）随着时间不变化，在两个高温度差区域各存在一个稳定的对流圈。在周期性对流阶段，对流特性参数随着时间周期性变化。两个低温度差区域各存在多个稳定的对流圈，在两个高温度差区域各存在一个周期移动的对流圈，移动周期随着格拉晓夫数Gr的增加而减小。两个高温度差区域的上部存在明显的温度羽。在非周期性对流阶段，对流特性参数随着时间非周期性变化。在3个对流阶段的变化范围内，平均努塞尔数、最大水平流速和最大垂向流速随着格拉晓夫数Gr的增加而增加。更多还原

【Abstract】 The dependence of convection under lateral periodic heating with Prandtl number Pr = 0.703 on Grashof number Gr is studied by numerical simulation of hydrodynamic equations.The results show that with the increase of Grashof number, there are three stages of convection pattern in the cavity, namely steady convection, periodic convection and non-periodic convection. The critical Graschof number for transition from steady convection to periodic convection is Gr = 1.448×10~4, and the critical Graschof number for transition from periodic convection to non-periodic convection is Gr = 1.348×10~6. In the steady convection stage, the convection characteristic parameters(horizontal velocity and vertical velocity) do not change with time, and there is a stable current loop in two regions with high temperature difference. In the periodic convection stage, the convective characteristic parameters change periodically with time. Several stable convective rolls exist in the two regions with low temperature difference, and there is a periodic moving current loop in the two regions with high temperature difference. The moving period decreases with the increase of Grashof number. The temperature plume exists in the upper part of two regions with high temperature difference. In the non-periodic convection stage, the convective characteristic parameter changes aperiodically with time. Within the range of three convective stages, the average Nusselt number,the maximum horizontal velocity and the maximum vertical velocity increase with the increase of Grashof number.更多还原