对底部等温加热、上端开口多孔介质中粘弹性流体进行了线性稳定性分析。使用了修正后的Darcy定律用于描述粘弹性流体在多孔介质内的流动特征，并引入了等压边界条件描述开口特征。使用了特征松弛时间（λ）和延迟时间（ε）表征粘弹性流体性质，并选择了4组不同的（λ）和（ε）作为算例对热对流启动时的临界瑞利数进行了数值求解。结果显示，松弛时间的增大会使得流体更易失稳，从而提前热对流的启动；而延迟时间的增大则会起到稳定流动的作用，使得热对流启动推迟。流动模式仅与延迟时间有关。扰动温度等值线图显示，其样式与边长（ a）和弹性参数有关。%This paper performed a linear stability analysis for investigating the onset of oscillatory convection of a viscoe -lastic fluid in an open-top porous medium heated from below .The modified Darcy ’ s law was used to describe the flow of the viscoelastic fluid in porous media and isobaric boundary conditions were introduced to describe the open features The relaxation time and retardation time were introduced to describe the viscoelastic behaviors .Four different combinations of and were selected to calculate the critical Rayleigh numbers corresponding to the onset of thermal convection .The results reveal that the increase of the relaxation time may make it easier to destabilize the flow ,leading to an earlier onset of ther-mal convection .In contrast ,the increase of retardation time tends to stabilize the flow and postpone the onset of convec-tion .The flow mode is only related with retardation time .The pattern of temperature disturbance is influenced by the geo-metric scale of the porous media and the viscoelastic parameters .
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