In the present paper an effect of gravity modulation in a horizontal parallel flat plate having micropolar nanofluid saturated by a porous medium is examined. Local thermal nonequilibrium (LTNE) has been observed for the problem, i.e., the fluid, particle, and solid matrix are at different temperatures. Onset of convection and heat and mass transfer for both the cases, i.e., linear stability and nonlinear stability, is analyzed. We conclude that rate of convection in the LTNE case is faster than in the LTE case. Effect of porosity is observed in the LTNE region, which is opposite to the effect observed in the LTE region. Increase in value of A, K₁, and δ delay the rate of convection. Small value of frequency of gravity modulation forms a greater number of small periods which delay the rate of convection. On increasing the value, heat transfer increases. At higher frequency of modulation we obtain the case similar to unmodulated case.

中文翻译：

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局部热非平衡和重力调制对微极纳米流体饱和多孔介质热不稳定性的综合影响

在本文中，研究了具有被多孔介质饱和的微极性纳米流体的水平平行平板中的重力调制效应。该问题已观察到局部热非平衡（LTNE），即流体、颗粒和固体基质处于不同的温度。分析了两种情况（即线性稳定性和非线性稳定性）的对流和传热传质的开始。我们得出结论，LTNE 情况下的对流速率比 LTE 情况下更快。在 LTNE 区域观察到孔隙率的影响，这与 LTE 区域观察到的效果相反。_{A、K 1}和δ值的增加会延迟对流速率。较小的重力调制频率值会形成大量的小周期，从而延迟对流速率。增加该值时，传热增加。在较高的调制频率下，我们获得与未调制情况类似的情况。