The study is concerned with entropy minimization on three-dimensional magnetohydrodynamic Oldroyd-B fluid flow with relaxation–retardation viscous dissipation and a mixed chemical reaction. A numerical solution of the nonlinear transport equations is obtained using an overlapping grid spectral collocation numerical scheme. We investigate strategies for entropy generation minimization in terms of system parameters such as the mixed convection parameter and changes in thermal and concentration fields under different conditions. Further, the findings on changes in the axial and transverse skin friction coefficients, the Nusselt number and the Sherwood number are presented.

中文翻译：

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不可逆比和熵产生对具有松弛缓释粘性耗散的三维Oldroyd-B流体流的影响

该研究涉及具有弛豫延迟粘性耗散和混合化学反应的三维磁流体动力学Oldroyd-B流体的熵最小化。非线性输运方程的数值解是通过使用重叠网格谱配值数值方案获得的。我们根据系统参数（例如混合对流参数）以及在不同条件下热场和浓度场的变化，研究使熵产生最小化的策略。此外，提出了关于轴向和横向皮肤摩擦系数，努塞尔数和舍伍德数变化的发现。