caa a22 4500 445812508 CHVBK 20180317145216.0 cr unu---uuuuu 170323e20111101xx s 000 0 eng 10.1007/s00419-011-0512-5 doi (NATIONALLICENCE)springer-10.1007/s00419-011-0512-5 Linear and nonlinear stability of double diffusive convection in a couple stress fluid-saturated porous layer [Elektronische Daten] [I. Shivakumara, Jinho Lee, S. Suresh Kumar, N. Devaraju] The linear and nonlinear stability of double diffusive convection in a layer of couple stress fluid-saturated porous medium is theoretically investigated in this work. Applying the linear stability theory, the criterion for the onset of steady and oscillatory convection is obtained. Emphasizing the presence of couple stresses, it is shown that their effect is to delay the onset of convection and oscillatory convection always occurs at a lower value of the Rayleigh number at which steady convection sets in. The nonlinear stability analysis is carried out by constructing a system of nonlinear autonomous ordinary differential equations using a truncated representation of Fourier series method and also employing modified perturbation theory with the help of self-adjoint operator technique. The results obtained from these two methods are found to complement each other. Besides, heat and mass transport are calculated in terms of Nusselt numbers. In addition, the transient behavior of Nusselt numbers is analyzed by solving the nonlinear system of ordinary differential equations numerically using the Runge-Kutta-Gill method. Streamlines, isotherms, and isohalines are also displayed. Springer-Verlag, 2011 Double diffusive convection nationallicence Couple stress fluid nationallicence Porous medium nationallicence Nusselt number nationallicence Shivakumara I. School of Mechanical Engineering, Yonsei University, 120-749, Seoul, South Korea aut Lee Jinho School of Mechanical Engineering, Yonsei University, 120-749, Seoul, South Korea aut Suresh Kumar S. Department of Mathematics, Siddaganga Institute of Technology, 572103, Tumkur, India aut Devaraju N. UGC-Centre for Advanced studies in Fluid Mechanics, Department of Mathematics, Bangalore University, 560 001, Bangalore, India aut Archive of Applied Mechanics Springer-Verlag 81/11(2011-11-01), 1697-1715 0939-1533 81:11<1697 2011 81 419 https://doi.org/10.1007/s00419-011-0512-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00419-011-0512-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Shivakumara I. School of Mechanical Engineering, Yonsei University, 120-749, Seoul, South Korea aut NATIONALLICENCE 700 1- Lee Jinho School of Mechanical Engineering, Yonsei University, 120-749, Seoul, South Korea aut NATIONALLICENCE 700 1- Suresh Kumar S. Department of Mathematics, Siddaganga Institute of Technology, 572103, Tumkur, India aut NATIONALLICENCE 700 1- Devaraju N. UGC-Centre for Advanced studies in Fluid Mechanics, Department of Mathematics, Bangalore University, 560 001, Bangalore, India aut NATIONALLICENCE 773 0- Archive of Applied Mechanics Springer-Verlag 81/11(2011-11-01), 1697-1715 0939-1533 81:11<1697 2011 81 419 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer