摘要
基于局部热不平衡模型(LTNE),本文研究了流体-多孔介质双层系统中Oldroyd-B流体双扩散对流的不稳定性问题,利用线性稳定性分析和Chebyshev配点法,得到了振荡对流下的临界瑞利数和临界波数以及中性曲线。文中主要分析了厚度比、溶质Rayleigh数、流固热传导系数比率、流固界面换热系数和粘弹性参数对系统稳定性的影响。经研究发现:较大的厚度比会破坏双层系统的稳定性,且会导致系统双峰特性消失;增加流固热传导系数比率时,系统会变得更不稳定,而增加流固界面换热系数则相反,且局部热不平衡对系统稳定性的影响发生在小波数区域;溶质Rayleigh数增强了系统的稳定性,同时促进了振荡对流的发生。
Based on the local thermal non-equilibrium(LTNE)model,this paper investigated the instability of double-diffusive convection for an Oldroyd-B fluid in a fluid-porous system.The linear stability analysis and the Chebyshev collocation method were used,and the critical Rayleigh number,the critical wavenumber,and the neutral curves under oscillatory convection were obtained.The effects of the thickness ratio,the solute Rayleigh number,the fluid-solid thermal conductivity ratio,the fluid-solid interfacial heat transfer coefficient,and the viscoelastic parameters on the system’s stability were analyzed.The results show that a greater thickness ratio destabilizes the two-layer system and results in the disappearance of the system’s bimodal characteristics.Increasing the fluid-solid thermal conductivity ratio makes the system more unstable,while increasing the fluid-solid interfacial heat transfer coefficient has the opposite effect.Local thermal non-equilibrium(LTNE)mainly influences the system’s instability in the lower wavenumber region.The solute Rayleigh number enhances the system’s stability and promotes the occurrence of oscillatory convection.
作者
李明
LI Ming(College of Mathematics,Nanjing University of Aeronautics and Astronautics,Nanjing 211106,China)
出处
《中北大学学报(自然科学版)》
2025年第6期818-826,共9页
Journal of North University of China(Natural Science Edition)
基金
江苏省青年基金(BK20170775)。
