Abstract The steady mixed convection flow along a vertical surface embedded in a porous medium with hybrid nanoparticles are examined. Both assisting and opposing flows are considered. We consider alumina (Al2O3) and copper (Cu) as the hybrid nanoparticles which are suspended in water to form Al2O3-Cu/water hybrid nanofluid. The similarity equations are gained from the governing equations using the similarity variables, and their solutions are obtained by the aid of the bvp4c solver in Matlab software. We found that there exist dual solutions for the case of opposing flow. Besides, it is noticed that the added hybrid nanoparticles delay the separation of the boundary layer. In addition, the velocity of the hybrid nanofluid is increased for the upper branch solutions, but the observation is reversed for the lower branch solutions as Cu nanoparticle increases.

中文翻译：

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混合纳米流体沿嵌入多孔介质中的垂直表面流动的混合对流

摘要 研究了沿嵌入多孔介质中的垂直表面的稳定混合对流流动，其中混合纳米粒子。辅助流和反向流都被考虑。我们将氧化铝 (Al2O3) 和铜 (Cu) 作为混合纳米粒子，它们悬浮在水中形成 Al2O3-Cu/水混合纳米流体。相似方程是利用相似变量从控制方程中得到的，它们的解是借助于Matlab软件中的bvp4c求解器获得的。我们发现对于逆流的情况存在双重解。此外，注意到添加的混合纳米粒子延迟了边界层的分离。此外，混合纳米流体的速度对于上分支溶液增加，